Patent application title: LAUNCHING DEVICE FOR CLAY TARGETS
Ferris Whidborne (Alton, GB)
IPC8 Class: AF41J920FI
Class name: Mechanical spring rotating about vertical axis
Publication date: 2012-06-07
Patent application number: 20120138034
A launching device for a clay target including a throwing arm supported
to be rotatable continuously about an axis, and including means to load a
clay target substantially at said axis, wherein the throwing arm includes
an escapement mechanism operable between a first position in which a clay
target is prevented from being launched from the throwing arm and a
second position in which a clay target is permitted to be launched from
the throwing arm. Loading means may be provided including a resilient
loading receptacle located substantially at the axis to provide
cushioning to a clay target as it is loaded. Further, the throwing arm
may include a base portion for bearing a clay target and a top cover
spaced from the base portion and adapted to disrupt the airflow over the
1. A launching device for a clay target including a throwing arm
supported to be rotatable continuously about an axis, and including means
to load a clay target substantially at said axis, wherein the throwing
arm includes an escapement mechanism operable between a first position in
which a clay target is prevented from being launched from the throwing
arm and a second position in which a clay target is permitted to be
launched from the throwing arm, the escapement mechanism including: a cam
member mounted to the throwing arm, the cam member carrying obstructing
means which, in the first position, obstructs the passage of a clay
target along the throwing arm, and in the second position, permits a clay
target to move along the throwing arm to be launched; and biasing means
for biasing the cam member towards the first position, wherein the
biasing means is a projection defined by the cam member on which
centrifugal force acts during rotation of the arm to bias the cam member
towards the first position.
3. The launching device of claim 21, wherein the throwing arm defines an internal volume and wherein the obstructing means is a resilient rod which, in the first position, projects into the said internal volume defined by the throwing arm so as to block the passage of a clay target therethrough.
4. The launching device of claim 1, wherein the rod is of plastics such as Nylon®, PTFE, or polyethylene.
7. The launching device of claim 1, wherein the biasing means further including a spring.
8. The launching device of claim 1, wherein the cam member is held in the first position against a clay target by a catch member, a portion of which is engageable with a first stop defined on a cam surface of the cam member thereby to limit angular movement of the cam member.
9. The launching device of claim 8, wherein the catch member is adapted to engage a trigger at a predetermined angular position as the throwing arm rotates, in use, so as disengage the catch member from the stop thereby to allow the cam member to move to the second position enabling a clay target to be thrown from the arm.
10. The launching device of claim 8, wherein the catch member is pivotably mounted and cooperates with the cam surface so as to adopt a position in which the cam member does not engage with the trigger circumstances where there is no clay target loaded in the throwing arm.
11. The launching device of claim 1, wherein the throwing arm includes an opening substantially at the axis through which opening sequential clay targets are loaded onto the arm by the loading means during rotation of the throwing arm.
15. The launching device of claim 1, wherein the loading means includes a resilient loading receptacle located substantially at the axis to provide cushioning to a clay target as it is loaded.
16. The launching device of claim 15, the loading receptacle including a base defining an impact zone for a clay target and a wall surrounding at least a part of the impact zone, and an open region opposing the wall that permits a clay target to travel in a launching direction.
17. The launching device of claim 16, wherein the base and the side wall together define one or more openings to permit debris to escape from the loading receptacle.
18. The launching device of claim 17, wherein a portion of the surface in the impact zone is inclined relative to the base whereby to provide a ramp to urge a loaded clay target in the launching direction.
19. The launching device of claim 18, wherein the inclined surface extends between a portion of the base and a portion of the side wall and defines first and second of the openings either side thereof.
20. The launching device of claim 19, wherein the loading receptacle includes a mounting flange that extends generally orthogonal to the base, the flange and the base defining a hinge therebetween.
21. The launching device of claim 16, wherein the base is provided with a resilient coating and/or low friction coating.
22. The launching device of claim 1, wherein the throwing arm includes a base portion for bearing a clay target and a top cover spaced from the base portion and adapted to disrupt the airflow over the clay target.
23. The launching device of claim 22, wherein the throwing arm includes an opening substantially at the axis through which opening clay targets are loaded onto the arm as it rotates.
24. The launching device of claim 23, including loading means to load sequential clay targets through the opening as the throwing arm rotates.
25. The launching device of claim 23, wherein a resilient loading receptacle is located at the opening thereby to offer cushioning to a clay target loaded thereon.
26. The launching device of claim 22, the top cover including one or more apertures to provide access to the internal volume of the throwing arm.
27. The launching device of claim 22, wherein the throwing arm further includes a runner to bear against a clay as it is launched, the runner including one or more openings to permit debris to be cleared from the throwing arm through rotation thereof.
29. The launching device of claim 8, wherein the cam surface of the cam member is provided with a second stop which stop is set a predetermined distance along the cam surface from the first stop in the direction of the projection for providing a two-stage release of the clay target, whereby with the clay target in the loaded position the throwing arm must revolve twice in order for the clay target to be launched.
30. The launching device of claim 29, wherein the catch member is adapted to engage the trigger at a predetermined angular position as the throwing arm rotates, in use, so as to disengage the catch member from the first and second stops thereby to allow the cam member to move to the second position enabling a clay target to be thrown from the arm.
 This invention relates to a launching device for clay pigeons, also known as clay targets, or skeets.
BACKGROUND TO THE INVENTION
 Whilst the term "game bird" may include partridge, pigeon, pheasant or fowl for example, in this specification the term pheasant will be used for game bird as the sport of pheasant shooting is currently the most popular and widespread.
 The majority of pheasant shooting in United Kingdom (UK) occurs on private estates and by far the largest number of these birds are harvested on `driven shoots`. Generally, a driven shoot involves a line of `guns` or `marksmen` who are positioned in formation in a location close to an area of wooded or covered land. A team of beaters proceeds to flush the pheasants from cover whereby the pheasants are urged to fly over the formation of guns and so are presented as flying targets to the row of marksmen below.
 In a sporting sense, it is preferable to have wild pheasant as targets. This is because wild pheasant exhibit more favourable characteristics such as eagerness to fly, high flight speed, and erratic flight paths, such characteristics contributing to a challenging target and improved overall enjoyment for the participants.
 The popularity of the sport of pheasant shooting has exploded over recent years encouraged, amongst other things, by the increasing use of the sport for corporate entertainment and business purposes and participation in the sport by high profile celebrities. Today, the scale of the sport of pheasant shooting is such that stocks of wild pheasant cannot sustain the vast numbers of organised shoots that occur. As a result, it has become necessary to rear pheasant artificially in captivity in order to supply the high numbers of pheasant that the sport requires. Nowadays, the pheasant is the most abundant game bird in the UK.
 Pheasant rearing has become a multi-million pound business in this country and pheasants are intensively reared on a large scale. During rearing, pheasant hens are typically kept in large numbers in a controlled environment and as a result, unnaturally large numbers of eggs are laid. These eggs are subsequently removed and artificially incubated until hatching occurs. The hatched chicks are transferred into multi-pen brooder systems typically designed to hold in the region of one to two hundred chicks. Following the brooder system, the chicks are moved to enclosed grass sites and finally onto a release site in order to acclimatise the chicks to increased freedom.
 The process outlined above enables a large number of pheasants to be reared in a short time period to replace the elevated numbers of pheasants killed in organised shoots. It is estimated that between 20 and 40 million pheasants are released each summer in the UK to support the annual pheasant harvest.
 Specific aims of artificially rearing pheasants in captivity for subsequent release are to supplement wild stocks and increase wild production, encourage the creation and management of habitat, and to provide economic considerations such as employment generation and sustainability of an industry. However, artificially rearing pheasants in close proximity and in increasingly large numbers and releasing them into the wild creates problems and carries with it a number of consequences, as will now be explained.
 Evidence shows that overstocking of captivity reared pheasants tends to suppress rather than supplement wild bird productivity. There is also evidence of negative ecological consequences. Firstly, habitat degradation tends to result from the increased number of birds in a given area as the pheasants forage for food and root up various indigenous woodland plant species, so depleting the soil and removing various species of insect that provide a food source to native birds and mammals.
 In addition, unnaturally high bird populations and high ground density increases the pheasants susceptibility to parasitic infections and other diseases and thereby the number of cases and types of infections and disease resulting in the significant growth in usage of medical compounds to combat the occurrence of such infections and disease. However, there are concerns about the direct effect of the favoured chemicals on the pheasants and the wider effect on general animal and human populations. One such compound, called Emtryl®, was claimed as the only available treatment for a number of game bird afflictions.
 However, Emtryl® was banned by the European Union in 1995 since its active ingredient DMZ (dimetridazole) was found to be carcinogenic, with there being no set safe maximum residue level and so posing a possible risk to human health whatever the concentration.
 As will now be appreciated, the intensive farming techniques employed to produce the elevated numbers of pheasants to sustain the pheasant shooting industry with live targets has numerous negative effects. It is indeed arguable that these practices are justified if, as a result, a sustainable stock of good quality pheasants is achieved, to provide a challenging target to the marksman. Unfortunately, however, these practices are dubious to say the least because they not only affect the environment but also the behaviour and performance of the pheasants as will be more readily apparent from the following.
 Crowded breeding units are an integral part of general intensive farming techniques and their use is well known by the public and heavily publicised and criticised by animal rights activists and action groups. As a corollary to this technique, artificially reared pheasants are also kept in cramped conditions in close proximity with other birds, so depriving the birds of the natural open-air environment for which they are biologically programmed. For instance, in the wild, pheasants tend to reside in groups of less than a dozen. The general close proximity to other birds and frequent movement from breeding unit to acclimatisation runs to release sites are a subsequent cause of stress among the birds, such stress manifesting itself in various ways. As an example, stress can interrupt feeding patterns and can also lead to aggression and bird-on-bird fighting.
 In an attempt to eliminate these behavioural traits, so-called "remedies" have been devised by the breeder including partially amputating beaks to dissuade fighting, fixing blinkers on the pheasants by means of pins through the nasal septum to limit forward vision, fitting plastic or metal `bits` to prevent closure of the beak and tying at least one wing to prevent escape.
 Because of their higher susceptibility to disease, captivity-reared pheasants suffer a greatly increased mortality rate when in the wild and in consequence comparatively few birds survive to continue to breed. Therefore, greater reliance is placed upon the stocks of introduced birds to sustain the shooting requirement. Generally, the quality of pheasants has declined and as such they tend to exhibit undesirable flight characteristics such as slowed flight, a lower flight path and an unwillingness to take flight and so are less challenging as flying targets.
 Clearly the practice of artificially rearing pheasants in captivity, for what some would contest as essentially a blood sport, has many disadvantages and numerous negative effects on the environment, health of native wildlife, humans, not to mention the humanitarian issue of the cruelty experienced by the pheasants whose only purpose to their short life is to be driven into the air to be shot down. In addition, as the numbers of birds destroyed per year grows, increasing proportions of birds are simply buried by virtue of the decreasing market for pheasant meat, so reducing the justification for such a sport still further.
 All this goes to show that there is undoubtedly a need for an alternative to the sport of shooting using live pheasants. However, any viable alternative must retain the enjoyment and entertainment of a live pheasant shoot whilst not requiring wounding or death of the pheasant. It is certainly conceivable that an individual may want to experience the enjoyment and exhilaration of shooting without suffering the moral dilemma of destroying large numbers of live flying targets.
 Alternatives to live flying target shooting are well known, the most widely recognised alternative being so-called "clay pigeons". A clay pigeon is typically a concave disc-shaped body of clay or other frangible material, which is usually coloured fluorescent orange or black, although other colours such as white, or yellow are frequently used in order that the clay pigeon can be clearly seen against varying backgrounds and/or light conditions.
 A clay pigeon is launched from a launching device called a "trap" causing it to rotate about its central axis to provide stability in the air where it presents a flying target for a marksman which shatters when hit by shotgun pellets. Such traps most commonly comprise a swinging arm powered by a stored energy means in the form of a spring, with the swinging arm pivotably mounted to a base and imparting the rotating motion to the target upon release of the spring. The throwing arm is manually cocked by pivoting the throwing arm about 180 degrees by which action the spring is extended or compressed.
 The clay pigeon and its use with traps is an accepted method for individuals to improve their shooting abilities of live pheasants and as a sport in its own right, generally known as clay pigeon shooting, and also as skeet shooting. Although clay pigeons avoid many of the above mentioned problems with live captivity reared pheasants, they also exhibit a number of characteristics that are undesirable from the view of an exponent of the sport of pheasant shooting.
 Firstly, since the typical clay pigeon has a relatively low mass and relatively high drag coefficient, velocity and rotational energy is eroded rapidly following initial release from the trap. This causes a clay pigeon to lose a significant amount of flight speed and hence height in the vicinity of the marksmen. This bears no resemblance to the behaviour of a live bird whatsoever which tends to fly fast and straight over the head of marksmen if driven directly in that direction. The typical flight range of a clay pigeon launched by a conventional spring-loaded trap from the ground is in the region of 50 to 60 metres and is appropriate for representing or simulating the flight path of a pheasant crossing the line of, or flying away from, the guns. Commonly however, pheasants are driven over the heads of the line of marksmen and it is in this scenario that clay pigeons are most ineffective. For example, if a typical effective range of a shotgun is taken to be in the range of 30 to 40 metres and if the clay pigeon is released around 20 metres from the gun, the clay pigeon will still be in range of a shotgun when it has landed.
 The fragile nature of the clay pigeon limits both its speed and range and the power that may be used to launch it. Firstly, increasing the initial velocity imparted to the clay pigeon raises the likelihood of it disintegrating upon release. However, simply making a clay pigeon heavier and stronger is undesirable since this reduces the chance of the clay pigeon fracturing when hit. Secondly, a clay pigeon is commonly manufactured with ridges or sharp angles in order to register hits from shot gun pellets with substantially shallow angles of incidence, such features reducing its aerodynamic properties.
 Another problem is presented by the nature of the trap itself. The launching arm of a conventional trap is spring-loaded and reciprocates from a cocked position to a released position whereby it launches the clay pigeon into the air. Once the launching arm has been released from its cocked position, it requires re-cocking, either manually by an operator, or automatically by an electrically driven system associated with the trap. This action is time consuming and limits the firing speed of the trap undesirably.
 Furthermore, the potential energy stored by the cocked throwing arm is a significant danger to the operator and accidents are common.
SUMMARY OF THE INVENTION
 An object of the present invention is to provide a trap, herein referred to as a `launching device` that can launch a clay target over a greater flight range than is possible using conventional traps, and to increase the rate at which it is possible to launch clay targets into the air accurately along a predetermined trajectory. Moreover, a further object is to provide a safer launching device with a reduced risk of injury to the operator.
 To this end, and from one aspect, the invention provides a launching device for a clay target including a throwing arm supported to be rotatable continuously about an axis, and including means to load a clay target substantially at said axis, wherein the throwing arm includes an escapement mechanism operable between a first position in which a clay target is prevented from being launched from the throwing arm and a second position in which a clay target is permitted to be launched from the throwing arm.
 The centrally/axially loaded throwing arm lends itself to efficient launching of clays since it avoids the time consuming process of re-cocking of a conventional spring-loaded trap. Moreover, once a clay target has been loaded onto the arm by the loading means, the escapement mechanism serves to arrest movement of a clay target along the arm until the arm reaches a predetermined radial position, whereby the escapement mechanism moves to its second operating position to allow the clay target to be launched into the air. In this way, successive clay targets that are launched from the throwing arm have predictable and consistent launch trajectories.
 In one embodiment, the escapement mechanism includes a cam member mounted to the throwing arm, the cam member carrying obstructing means or a `retaining member` which, in the first position, obstructs the passage of a clay target along the throwing arm, and in the second position, permits a clay target to move along the throwing arm to be launched.
 The escapement mechanism acts to arrest movement of the clay target along the throwing arm until the arm is in a suitable position to launch the clay target. To reduce the likelihood of a clay target breaking when it impacts the obstructing means, in one embodiment the obstructing means takes the form of a resilient rod which, in the first position, projects into an internal volume defined by the throwing arm so as to block the passage of a clay target therethrough. So that the rod has the correct degree of resilience, preferably the rod is of plastics such as Nylon®, PTFE or polyethylene.
 Once the cam member has rotated to permit a clay target to push past it, biasing means preferably are included to urge the cam member to return to the first position. Although the biasing means may be a spring, in one embodiment the biasing means is a projection defined by the cam member on which centrifugal force acts during rotation of the arm to move the cam member angularly towards the first position.
 An additional spring may be provided to ensure that the cam member is moved angularly when it is in an extreme angular position so as to complement the biasing force provided by the projection.
 In order to make sure that the cam member is held in its first position until the appropriate time, it may be provided with a catch member, a portion of which is engageable with a stop defined on a surface of the cam member. Engagement between the catch member and stop therefore limits angular movement of the cam member until the catch member engages triggering means, preferably associated with a frame to which the throwing arm is mounted, at a predetermined angular position as the arm rotates. Interplay between the triggering means and the catch member causes the catch member to lift clear of the stop which allows a clay target to push against the rod, which moves the cam member and allows the clay target to be launched from the arm under the action of centrifugal force.
 In order to enable a succession of clay targets to be loaded onto the throwing arm as it rotates, the arm is provided with an opening substantially located at its axis. The opening enables manual loading of clay targets or, more preferably, and more safely, clay targets may be loaded by an automatic loading mechanism such a magazine of the type used with conventional clay target traps.
 Expressed in another way, the invention provides a method of launching a clay target including rotating a throwing arm about an axis thereof, loading successive clay targets substantially at the axis of the throwing arm during rotation of the arm, arresting movement of each one of the clay targets, in turn, against centrifugal force exerted thereon and permitting said arrested clay target to be launched from the arm at a predetermined angular position thereof.
 In order to reduce breakage of clay targets as they are loaded onto the throwing arm, the method may also include cushioning the landing of each one of the clay targets as they are loaded at the axis of the throwing arm.
 Furthermore, in order to encourage each of the succession of clay targets to fly straight and level the method may include disrupting the airflow over each one of the clay targets as it is launched along the throwing arm. Disrupting the airflow in this way guards against en edge of the clay target lifting clear of the throwing arm, which tends to result in the clay target being launched on a tilt reducing the likelihood of a consistently straight flight trajectory.
 The invention provides a way to launch a succession of clay targets along a predetermined flight path quickly and accurately which is a great advantage over conventional clay target traps which are based on the technology of a spring loaded pivotable arm which fires clay targets one-by-one.
 However, an important consideration associated with launching successive clay targets at a high `rate of fire` is to reduce the incidence of clay targets breaking, as they are loaded, or during a launch. Therefore, in another aspect, the invention provides a launching device for a clay target including a throwing arm supported to be continuously rotatable about an axis, and including loading means to load a clay target substantially at said axis, wherein the loading means includes a resilient loading receptacle located substantially at the axis to provide cushioning to a clay target as it is loaded.
 Since clay targets are fragile items, prone to breaking, cushioning the landing of the targets in this way contributes greatly to reducing the number of clay targets that tend to break.
 The loading receptacle may include a base defining an impact zone for a clay target and a side wall surrounding at least a part of the impact zone, and a open region opposing the side wall that permits a clay target to travel in a launching direction. The impact zone may provide cushioning itself, for example by carrying a resilient coating of rubber, foam or the like, or be spring loaded to provide a degree of give when a clay targets lands on it. In one embodiment however, the loading receptacle includes a mounting flange that extends generally orthogonal to the base, the flange and the base defining a hinge therebetween that provides the impact zone with the necessary cushioning.
 Because it is possible that some clay targets will still break despite the provision of cushioning, the loading receptable also may be provided with means to clear any debris away from the impact zone quickly. To this end, the base and the side wall may together define one or more openings to permit debris to escape from the loading receptacle.
 Since the clay targets are loaded substantially at the axis of the throwing arm, the centrifugal force acting of the targets at the point of loading will be negligible. Therefore, in order to provide an initial pulse to move the clay targets in the direction of launch, a portion of the surface in the impact zone may be inclined relative to the base so as to provide a ramp which urges a loaded clay target in the launching direction. Conveniently, the inclined surface may extend between a portion of the base and a portion of the side wall to define the first and second of the openings either side thereof.
 Optionally, the base may be provided with a suitable low friction coating such as PTFE or FEP (TEFLON®), or also a graphite-based low friction paint for example. Such a coating will encourage clay targets to move from the base of the loading receptacle into the internal volume of the throwing arm.
 In connection with continuously rotatable throwing arms, but also relating to convention spring-loaded reciprocating throwing arms, the Applicant observed that clay targets are inclined to launch at a tilt to the plane of the throwing arm. The effect of this is that the clay target tends not to fly on a straight trajectory, as is preferable, but instead tends to fly in a curved trajectory in the general direction of the tilt.
 To this end, and in another aspect, the invention provides a launching device for a clay target including a throwing arm supported to be rotatable about an axis, wherein the throwing arm includes a base portion for bearing a clay target and a top cover spaced from the base portion and adapted to disrupt the airflow over the clay target.
 The invention has particular utility to the type of launching devices described herein, that is to say those having throwing arms that rotate continuously in use and having an opening substantially at the axis of the throwing arm through which opening successive clay targets are loadable onto the arm as it rotates. Preferably, to enable a succession of targets to be launched quickly to provide a challenge to the shooters, there may be provided loading means configured to load a plurality of targets onto the loading arm through the opening one-by-one.
 In order to provide access to the internal volume of the throwing arm, the top cover may be provided with one or more apertures. Furthermore, the throwing arm may be provided with a runner against which a clay target bears as it is launched, the runner including one or more openings to permit debris to be cleared from the throwing arm through rotation thereof.
 It should be appreciated that preferred and/or optional features of the various aspects of the invention may be combined with one another.
BRIEF DESCRIPTION OF THE DRAWINGS
 In order that the invention may be more readily understood, some embodiments in accordance therewith will now be described, by way of example, with reference to the accompanying drawings, in which:--
 FIG. 1 is a perspective view from the right hand side of a launching device for a clay target in accordance with an embodiment of the invention;
 FIG. 2 is a perspective view of a loading receptacle for the launching device of FIG. 1;
 FIG. 3 is a view from above of a throwing arm of the launching device of FIG. 1;
 FIG. 4 is a perspective view of an escapement mechanism of the launching device of FIG. 1;
 FIG. 5 is a view from above of the escapement mechanism in FIG. 4 in a first operating position;
 FIG. 6 is a view from above of the escapement mechanism in a second operating position; and
 FIG. 7 is a view from above of the escapement mechanism in a third operating position.
 In the drawings, the same reference characters designate the same or similar parts.
DETAILED DESCRIPTION OF THE EMBODIMENTS
 A launching device, generally indicated at 2, comprises a supporting base 4 from which depends three legs 6 supporting the launching device on the ground (not shown), and a launch assembly 8 rotatably mounted on the base 4.
 The legs 6 are fixed to the base 4 by bolts 10 which allows the legs 6 to swing between a closed position, in which the legs 6 lie substantially parallel to one another, to an open position so as to define a stable triangular footprint, as shown in FIG. 1.
 The rotatable mounting for the launch assembly 8 comprises a box-section steel hub 12 having a rigid, circular in cross-section, shaft 14 that depends downward from the centre of the hub 12 and extends through a tubular bearing collar 16 defined by the base 4. The hub 12 is therefore moveable angularly about the axis of the shaft 14.
 The launch assembly 8 is mounted to the hub 12 via a frame-like support platform 18 comprising a laterally extending box-section steel beam 20 that is mounted to two upwardly extending flanges 22 provided at either end of the hub 12.
 The beam 20 includes a bracket 24, also of box-section steel, that is attached to the beam 20 by welding. The bracket 24 is provided with two tabs 26 (only one of which is shown in FIG. 1) extending perpendicularly away from the bracket 24, each tab 26 being pivotably mounted as by bolts 28 to a respective one of the flanges 22 so as to form a hinge. Therefore, the support platform 18 is pivotable about the hinge such that the pitch of the launch assembly 8 can be varied.
 To allow an operator to control the pitch and angular position of the launch assembly 8, the support platform 18 also comprises an attitude control arm 30, of box-section steel, which extends perpendicularly away from the approximate mid point of the lateral beam 20. The attitude control arm 30 has a length sufficient to enable an operator to stand clear of the launch assembly 8 when it is in operation, and provides leverage on the support platform 18 enabling the operator "aim" the launching assembly 8 angularly, and in pitch, without a great deal of effort.
 The principal function of the support platform 18 is to carry a throwing arm 32 of the launch assembly 8. The throwing arm 32 is rotatably mounted to the support beam 20 by way of a mounting pin (not shown) that depends from the rotational axis of the arm 32 and projects through a through-hole provided in the lateral beam 20 and the bracket 24. The mounting pin is secured to the beam 20 and bracket 24 by respective upper and lower mounting collars 34, 36, respectively.
 In order to rotate the throwing arm 32, the lower collar 36 is concentrically mounted to a pulley wheel 38 that cooperates with an endless drive belt 40. The drive belt 40 also cooperates with a driving pulley wheel which is attached to an electrically driven DC motor that is mounted on the lateral beam. It should be appreciated that the driving pulley wheel and the DC motor are not shown in FIG. 1 but are conventional.
 The throwing arm 32 takes the form of an elongate member somewhat shorter that the length of the lateral beam 20 and which is defined by two halves; each one of the halves extending radially from the centre of the throwing arm 32. A loading aperture 42 is defined at the centre of the throwing arm 32 by which means clay targets can be loaded into the throwing arm as it rotates to be flung from an operating portion 44 of the arm 32 as will be described further herein. The other half portion 46 of the throwing arm 32 constitutes a counterbalance weighted to ensure that the throwing arm 32 is balanced as it is rotated at an operational speed of up to approximately 500 rpm.
 In order to keep operators and bystanders safe from the rotating launch arm a generally semi-circular protective cover 50 (shown in FIG. 1 in dashed-lines) is mountable to the launch assembly 8 at mounting lugs 52 provided at each end of the lateral beam 20 and a further lug 54 provided on the end of the attitude control arm 30 remote from the lateral beam 20. To secure the cover, the lug 54 is provided with a screwable handle 56 which is turnable to secure the cover 50 to the support platform 18.
 Although not shown in FIG. 1, it should be noted that a front cover may also be mounted to at further lugs 53 provided on the main cover 50 for providing protection to the throwing arm 32 during transportation of the device. The further cover may also be provided with a suitable aperture to permit clays to be launched through it, such an aperture allowing the cover to remain in place during operation. It should be noted at this point that the cover could be formed from any material that has sufficient rigidity to withstand potential impacts with the throwing arm, or impacts from objects striking the cover. For example, the cover could be metallic, such as sheet steel/aluminium or, alternatively, the cover could be a vacuum moulded plastics such as HDPE.
 Although clay targets may be loaded into the loading aperture 42 by hand, an automatic loading means is provided on the cover 50 in the form of a magazine assembly 58 (also shown in dash-lines) for holding a plurality of clay targets and dispensing targets one-by-one into the loading aperture. It should be noted that the precise details of the protective cover 50 and the loading magazine assembly 58 are not essential to the present invention and will not be described in further detail here.
 The loading aperture 42 of the throwing arm 32 is defined by a tray-like receptacle 60, shown more clearly in FIG. 2, which includes a substantially flat base 62 having an open front end (to the left in the orientation shown) and a rear end that is closed by a raised semi-circular wall 64 that is attached to the platform base 62 by two tabs 66, one extending upwards from either side of the base 62. An oblong flange 68 depends downwardly from the front edge of the base 62 substantially at right angles along a hinge line 70 and provides a means to mount the loading receptacle 60 to the superstructure of the throwing arm 32 by way of two mounting holes 72. The hinged relationship between the base 62 and the mounting flange 68 imparts the loading receptacle 60 with a degree of resilience or `give` that provides a relatively cushioned landing to a clay target that is dropped onto the loading receptacle 60. This reduces the likelihood of a clay target breaking on impact, which is beneficial since a high number of broken clay targets is wasteful and can lead to blockages. Further, although the resilience of the loading receptacle 60 could be provided by other configurations, for example the base 62 could be sprung loaded or be formed of or carry a resilient/shock absorbing material such as dense foam or rubber, the hinged base 62 provide a simple and elegant solution to the problem of breaking clays.
 The loading receptacle 60 also includes two cut-outs 74 defined towards the rear end which extend from the base 62 to the raised wall 64. The two cut-outs 74 define an inclined tongue 76 between them that is integral with the base 62 and extends at an oblique angle therefrom so as to join to the raised wall 64. The tongue 76 serves to impart a lateral force to a clay target as one is dropped onto the base 62 since the edge of the clay target will contact the tongue 76 before contacting the base 62 which will incline the clay target and "push" it towards the open end of the base 62. This action moves the clay target away from the axis of rotation of the throwing arm 32 thus ensuring that centrifugal force acts on the clay target to launch it from the arm. To facilitate this, the base 62 may be provided with a low resistance coating, for example of Teflon (trade mark) or a graphite-based paint so that a clay target will slide over the base more easily. Although in this embodiment, the base 62 is substantially flat and lies in the same plane as the throwing arm, the base 62 may also be inclined slightly relative to the plane of the throwing arm to help a clay slide off the tray and along the throwing arm.
 Although the resilience of the loading receptacle 60 cushions the fall of a clay target so as to reduce the likelihood of breakage, in the event that a clay target does break on impacting the zone defined by the base 62, the cut-outs 74 provide a means for any fragments to be flung away from the loading area thus guarding against the possibility of fragments travelling along the throwing arm 32 potentially blocking the passage of a subsequently loaded clay target. The loading receptacle 60 can therefore be considered to be self-cleaning by virtue of the holes defined by the cut-outs 74.
 Although one specific structure of loading tray is described above, the reader will appreciate that it is not essential that the loading tray be a separate component that is attachable to the throwing arm and that the main functional features of the loading tray could be incorporated into other tray-like structures. For example although in the embodiment in FIG. 2 the flange 68 allows the loading tray 60 to be mounted to a part of the throwing arm, it should be noted that the feature of the resilient inclined base 62 could be made as integral components to a suitable throwing arm, as could the semi-circular end wall 64 and the cleaning holes 74.
 It should be noted that although the loading receptacle has particular utility in the launching device described herein, it is also applicable to conventional traps such as those using a spring-loaded reciprocating arm.
 Returning to the throwing arm 32 as shown in FIG. 1, and as shown from above in FIG. 3, the operating portion 44 of the throwing arm 32 includes a lower plate 80 along which a clay target 81 rides as it is launched from the throwing arm 32, and an guide rail or runner 82 which provides an upright surface that bears on a corresponding upright surface of the clay target 81. Note that the guide rail defines one or more openings to allow debris to be cleared from the arm automatically, in use. A cover plate 84 is attached to the lower plate 80 as by bolts 86 along both its leading edge 88 and its trailing edge, namely the guide rail 82, and encloses substantially the entire length of the lower plate 80 in this particular embodiment. The cover plate 84 includes a plurality of apertures 90 (four of which are shown in FIG. 3) which serve to reduce the weight of the throwing arm 32, as well as to provide access to the internal volume of said arm. Alternatively, a single aperture may be provided running generally along the length of the throwing arm 32.
 A purpose of the cover plate 84 is to reduce the airflow over a clay target during launch so as to disrupt its aerodynamic properties, as a result of which the clay target is discouraged from lifting off of the lower plate 80 as it gathers speed along the throwing arm 32. This helps to ensure that the clay target is launched substantially co-planar with the lower plate 80 thereby encouraging a straight flight path avoiding "hook" or "slice". Furthermore, the cover plate 84 also prevents the clay target lifting of the lower plate by providing a physical barrier to vertical movement of the target. Although in this embodiment, the plate is shown running the length of the arm, it should be appreciated that this is not essential and the plate may instead extend a along a lesser portion of the arm, so long as the aerodynamic properties of the clay target are still disrupted sufficiently to prevent it lifting whilst on the arm.
 To ensure that a clay target is released from the throwing arm 32 at the correct point during its rotation an escapement means or mechanism 90 is provided, which is shown generally in FIG. 3, and in more detail and in various operating positions, in FIGS. 4 to 7.
 The escapement mechanism 90 includes a cam release assembly 92 that is mountable to the throwing arm 32 by way of a mounting plate 94 as by the illustrated bolt holes 96 shown in FIG. 4, and includes a downwardly depending pivot pin 98 that extends through a hexagonal boss 100 that is coupled to one end of the mounting plate 94 as by welding. The cam release assembly 92 includes a generally semi-circular cam member 102 having a rounded cam surface 104 which blends into a weighted projection 106, the purpose of which will become clear in the foregoing description.
 A planar flange 108 extends from the boss 100 at an angle to the mounting plate 94 and provides a mounting point at a pivot bolt 110 for a catch member or `plate` 112 that is biased into engagement with the cam surface 104 by way of a spring 114. The catch plate 112 includes a dog 112a arranged to abut a stop notch 116 defined by the cam surface 104 by which means anti-clockwise angular movement of the cam member 102 is limited. The catch plate 112 is engageable with trigger means 118 (shown in FIG. 3) that is mounted to the support platform 18 and so remains stationary relative to the throwing arm 32. The trigger means 118 comprises a rotatable trigger wheel attached via a mounting tab 120 to an arcuate positioning plate 122 which, in turn, is mounted to the support platform 18 between the beam 120 and the control arm 30. The positioning plate 122 includes a plurality of elongage apertures 124 which enable the angular position of the trigger wheel 118 to be altered by mounting the tab 120 to a different one of the apertures.
 Returning to the escapement mechanism 90, a clay target obstructing means in the form of an elongated rod 130 is mounted to the cam so as to project into the throwing arm 32. More specifically, the rod 132 is received by a bore 132 defined in a mounting block 134 which is carried on an upper surface of the cam member 102 and secured thereto as by welding/brazing. A portion of the rod 130 is secured in the bore 132 by fixing screw 131 that extends through the mounting block 134 to impinge on the rod 130, whilst a free end of the rod 130 is arranged to project through an aperture in the side of the throwing arm 32 into its internal volume and is operable between three positions, in use, to arrest movement of a clay target within the throwing arm or to release a clay target from the throwing arm as will now be described in detail with reference to FIGS. 5, 6 and 7. Other means of mounting the rod relative to the arm would be apparent to the skilled person.
 In FIG. 5, the cam assembly 90 is shown in a position in which there is no clay target in the throwing arm 32 and so the cam assembly adopts an "unloaded" position in which the cam member 102 is at maximum angular position in the clockwise direction, having the mounting plate 94 as a frame of reference. It should be noted that the cam assembly is shown bolted to the throwing arm 32, a portion of which is shown ghosted for clarity.
 The cam member 102 is urged into the aforesaid position by two principal forces acting on it: firstly, a force due to a biasing spring 136 and, secondly, the centrifugal force exerted on the weighted projection 106 as the throwing arm 32 is spinning. It should be noted that in FIG. 5, the cam member 102 is shown in its maximum clockwise position which is determined by a portion of the planar flange 108 that is shaped to cooperate with a raised portion of the cam surface 104 thus limiting further clockwise movement. Although not shown in FIG. 5, alternatively the cam member 102 may be provided with a stub or lobe located towards the projection 106 against which the flange 108 may abut to define the maximum limit of clockwise rotation of the cam member 102.
 Once a clay target has been dropped into the loading receptacle 60 of the throwing arm 32, it is flung along the arm 32 under the action of centrifugal force and therefore will come into contact with the retaining rod 130. The rod 130 is a suitable plastics material, such as PTFE or Nylon®, having sufficient strength and rigidity to hold the clay target in place, whilst having a degree of resilience so that it `gives` on impact to guard against undesirable breakage of the clay target at this point.
 As the clay target encounters the retaining rod 130, the cam assembly 90 is caused to move angularly anti-clockwise during which movement the dog 112a of the catch plate 112 rides over the cam surface 104 until it comes into contact with the stop notch 116: FIG. 6 shows the cam assembly 90 in this first or `loaded` operating position, in which circumstances the cam assembly is ready to be triggered to release the clay target (partly shown as 140) from the throwing arm 32.
 The cam surface 104 has a region 137 of reducing radius as it approaches the stop notch 116 which causes the catch plate 112 to move angularly around its mounting pivot bolt as it rides over the cam surface 104. The end of the catch plate 112 remote from the cam surface 104 therefore swivels outwardly into a position having a radius from the axis of the throwing arm 32 substantially the same as the radial position of the trigger wheel 118.
 As the throwing arm 32 rotates, the catch plate 112 comes into contact with the trigger wheel 118 which causes the catch plate 112 to swivel about the pivot bolt 110 such that the dog 112a lifts clear of the stop notch 116. This "releases" the cam assembly 90 and the clay target 140 is able to push past the retaining rod 130 which moves the cam assembly 90 angularly in an anti-clockwise direction, as is shown in FIG. 7.
 Once the clay target has been thrown from the arm 32, past the rod 130, the cam member 102 is urged angularly in a clockwise direction by way of the action of the biasing spring 136 and due to the centrifugal force acting on the cam projection 106 and so the cam member 102 returns to the position shown In FIG. 5, ready for to receive the next clay target. The process described above with reference to FIGS. 5, 6 and 7 will repeat each time a clay target is loaded into the throwing arm 32, the escapement mechanism 90 and the trigger wheel 118 cooperating to ensure that each clay target is thrown from the arm 32 at the same angular position as the arm rotates, thus providing that subsequent clay targets are launched with consistent flight paths.
 In an alternative embodiment (not shown), the cam surface 104 is provided with a further stop notch set a predetermined distance along the cam surface 104 in the direction of the projection 106; a suitable distance between the stop notches is between approximately 5 mm to 10 mm, and preferably about 6 mm to 8 mm. The effect of this modification is to provide a two-stage release of the clay; in other words, with the clay target in the loaded position, the throwing arm 32 must revolve twice in order for the clay target to be launched. This enables the clay target to `bed in` to the loaded position for a longer period ensuring greater accuracy in the launch trajectory and better shot-to-shot consistency. A further benefit is that the impact force between the clay target and the rod 132 is lessened since the clay target first comes into contact with the rod 132 at a position closer to the axis of the throwing arm 132 so the clay is moving more slowly at the point of impact thus reducing the risk of breakage.
 The skilled reader will appreciate that various modifications may be made to the specific embodiments described with reference to the drawings without departing from the scope of the invention as defined in the appended claims. Some are explained above; others will now be described.
 Although several components of the launching device are described as being made from tubular or box-section steel, for example the lateral beam 20, the attitude control arm 30, the hub 12, and others, it should be appreciated that this need not be the case and other materials and, moreover, shapes are appropriate. The main objective of the aforesaid components is to provide a supportive platform to which the rotating throwing arm may be mounted and to enable it to be aimed by an operator.
 Furthermore, although the escapement mechanism includes wire springs to bias the catch plate and the cam member, these should not be considered to limit the scope of the invention as defined by the claims and it should be appreciated that forms of springs other than those shown in the drawings are considered equally appropriate. For example, the cam member may instead be biased by a coil spring housed internally within the hexagonal boss.
 Although the drive arrangement has been described above as comprising an electric motor that drives the pulley wheel 38, it should be noted that this particular configuration is not essential and that other drive arrangements would be apparent to the skilled person. For example, the drive arrangement could comprise a DC motor which drives the central shaft of the throwing arm directly, the motor including an electronic speed controller to provide a range of rotation speeds for the throwing arm.
 In the embodiment described above, the trigger wheel 118 is attached to the positioning plate by bolts. However, it should be noted that the positioning plate could be replaced with an electronically controlled moveable rack system which is operable to vary the angular position of the trigger wheel, resulting in a variable release point for the clay target. Furthermore, the trigger wheel may instead by a wedge or something similar that achieves the same effect as a wheel.
 In an improvement to the launching device, a storage carousel for clay targets may be mounted to the device so as store several hundred clay targets and to provide an automatic loading function. In order to ensure that the launching angle of the clay targets is consistent shot-to-shot, the radial position of the trigger wheel may be linked to the rotation of the carousel so that as a clay target is dropped out of the carousel, the trigger wheel is held out of position by a cam. Once the carousel beings to turn, the trigger wheel would move into the correct radial position for engagement with the escapement mechanism thus allowing a clay target to be launched.