Patent application title: Articulated Kneeboard for Concrete Finishers
Darrell Mcdaniel (Flowery Branch, GA, US)
IPC8 Class: AA41D1306FI
Class name: Guard or protector leg knee pads or rests
Publication date: 2008-12-04
Patent application number: 20080295213
Patent application title: Articulated Kneeboard for Concrete Finishers
SHOEMAKER AND MATTARE, LTD
Origin: SILVER SPRING, MD US
IPC8 Class: AA41D1306FI
A kneeboard for concrete worker has a knee pan which contains a cushioned
knee pad, and a toe pan. The pans are interconnected by links which
permit them to pitch with respect to one another, so that the pans can
remain flush even when they are on different non-coplanar surfaces. This
enables a concrete finisher to move over steps and obstacles without
damaging the surface of the concrete.
1. An articulated kneeboard for concrete finishers, said kneeboard
comprisinga knee pan,a toe pan, andstructure interconnecting said pans in
a way that permits each of the toe pans to pivot with respect to the
other about at least one axis, whereby the pans can rest flush on
respective non-coplanar surfaces.
2. The invention of claim 1, wherein the interconnecting structure is a pair of laterally spaced links, each extending between the knee pan and the top pan, and the links are connected to each pan by a movable joint.
3. The invention of claim 2, wherein each movable joint is a pin joint.
4. The invention of claim 2, wherein each movable joint is a universal joint.
5. The invention of claim 2, wherein each of said links is length adjustable.
6. The invention of claim 1, further comprising a resilient knee pad secured in said knee pan.
7. The invention of claim 1, further comprising an accessory holder attached to said knee pan.
8. The invention of claim 1, wherein each of said pans has a broad flat bottom.
9. The invention of claim 8, where the knee pan has sloping surfaces extending front and rear from said flat bottom.
10. The invention of claim 1, wherein each of the pans has slots for receiving respective retaining straps.
11. The invention of claim 1, wherein said pivot axis is transverse to a longitudinal axis extending between said pans.
This application claim benefit of provisional patent application
60/932,152, filed May 29, 2007.
BACKGROUND OF THE INVENTION
This invention relates to a kneeboard for concrete finishers.
After concrete pads are poured, while they are still wet, they have to be finished to have a smooth, flat surface.
Prior inventors have proposed various kneeboards, all intended to permit a worker to move about a wet concrete floor without sinking into it, so as to minimize disturbance to the floor surface while it is being finished. Representative patents include U.S. Pat. No. 6,347,404 to Iskra, U.S. Pat. No. 5,125,479 to Nemes et al., U.S. Pat. No. 4,789,046 to McDowall, U.S. Pat. No. 4,747,470 to Fernandez and U.S. Pat. No. 4,346,784 to Hammond.
U.S. Pat. No. 2,719,576 discloses a knee-board for cement finishers. There is a single strap, halfway between the knee pad and the toe holder.
U.S. Pat. No. 3,025,526 discloses a kneeling device which straps to the leg, behind the knee and the ankle. There is a link which can pivot and when it does, the knee socket slides along the board.
U.S. Pat. No. 6,347,404 discloses a cement finishing board which has a floating knee holder in combination with a toe holder.
U.S. Pat. No. 3,084,458 shows a two-part float, with one part for the knee and one for the toe.
While all of the above are useful, they do not solve a common problem: that of negotiating steps and obstacles on uncured concrete surfaces.
SUMMARY OF THE INVENTION
An object of the invention is to provide a comfortable kneeling apparatus for a concrete floor finisher, designed so that all parts of the apparatus remain flush with the floor surface even as the worker moves over an obstacle such as step between surfaces of different heights. A related object is to keep the weight-supporting components of the apparatus flush with the respective surfaces, so as not to mar either, and also to protect the top edge of the step from damage.
The present invention differs from the above patents in that it has articulated front and rear pans joined by a pair of links which permit the pan at either end to pitch or pivot with respect to the other.
These and other objects are attained by a kneeboard for a concrete worker, as described below.
We use the aeronautical terms pitch and roll to define possible movements of the pans of this invention, with respect to the longitudinal axis of the device which is defined as an imaginary line drawn between the centers of the two pans.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings,
FIG. 1 is an isometric view of an articulated kneeboard embodying the invention;
FIG. 2 is a top plan view thereof, and
FIG. 3 is a front elevation thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1-3, an articulated kneeboard embodying the invention has two major components: a knee pan 10 and a toe pan 30. The knee pan contains a resilient knee pad 12, which is secured to the pan by a bracket 14 in a way that makes pad replacement possible when the pad becomes wet, worn or dirty.
The toe pan 30 is smaller than the knee pan, and has an elevated railing 32 supported by four tabs 34 which extend upward from the sides 36 and ends 38 of the pan. The depth of the pan is about two inches and the railing, which preferably is made from 1/4'' round stock, is about and inch above the top of the pan. The railing circumscribes an irregular polygon designed to receive the toe of a worker's boot.
The two pans are interconnected by at least one articulating link, preferably by a pair of laterally spaced links 20 that are attached by joints such as pins or bolts 22 at either end to the left and right sides 12, 14 of the pans. The pins or bolts pass through holes formed in U-shaped brackets 40 affixed to the opposed front and rear walls of the toe and knee pans, respectively. The pins or bolts define axes "A" and "B" about which each pan can pitch with respect to the other pan. On a flat floor, the pans remain coplanar and do not need to pitch with respect to one another; however, the fact that they can pitch enables them to remain flat on the floor even when they straddle a step "S" (FIG. 3) between floors of different heights. That is a particular advantage of this invention.
While pin-type joints are presently preferred, it should be understood that other types of joints such as universal ball joints could be used, and in fact those might be preferable for certain applications. Ball joints would enable the pans not only to pitch relative to one another, but also to roll relatively, in which case the articulated kneeboard could straddle a step between non-parallel (skewed) surfaces, while nevertheless remaining flush with each surface.
Preferably, the links can be adjusted for length to accommodate different size users. In the example illustrated, each link has two telescoping parts 23, 24 can be incrementally adjusted by inserting one or more pins or bolts 26 into selected spaced holes 28 in the telescoping parts. Alternative length adjustment schemes might be used. For example, the telescoping parts could be joined by helical threads so that their combined length could be changed by turning one with respect to the other.
It is also conceivable that the two links illustrated might be replaced by a single element, for example a broad horizontal plate having hinges at either end, or a bar having universal joints (e.g., ball-and-socket) at either end.
An accessory holder 50 is preferably affixed to the front end of the knee pan, to provide a convenient receptacle or retainer for beverage containers, tools, product cans and the like. The illustrated accessory holder has four upwardly extending fingers 52 to retain a container within the holder as the worker moves about. The holder is connected to the knee pan by bolts 54.
The depth of the knee depression is about two inches, and the center lines of the links are slightly lower. These preferred dimensions are not critical and can be varied if necessary to provide a particular clearance as the link passes over step edges. The link could be arched vertically, if desired, to increase that clearance.
Each of the pans is made of sheet metal, and has a broad, flat bottom surface with upwardly bent left and right sides. Sloping surfaces lead into the flat bottom at its front and rear.
Strap-retaining slots 56 are formed in each of the left and right sides of each pan. Flexible fabric straps (not shown) are inserted through the slots.
In use, a worker straps the knee pan to one shin so that the knee is held against the knee pad, and places his toe in the toe pan. While the person is working on the floor, his weight is broadly distributed by the large areas of the pans, particularly the knee pan, which bears most of his weight as he leans forward. The knee pan is therefore the larger.
Because the flat bottoms of the articulated kneeboards can always remain flush against the surface on the concrete slab, less time is needed on the job fixing the bumps and creases that makeshift solutions usually cause.
The materials and dimensions mentioned above are merely preferred, and it should be understood that modifications and variations are expected. For example, the pans might be made of a non-metallic material. Since the invention is subject to modifications and variations, it is intended that the foregoing description and the accompanying drawings shall be interpreted as only illustrative of the invention defined by the following claims.
Patent applications in class Knee pads or rests
Patent applications in all subclasses Knee pads or rests