US2724593A

US2724593A - Back stop for bowling alley

Info

Publication number: US2724593A
Application number: US252107A
Authority: US
Inventors: Sherman Kenneth Clark
Original assignee: General Dynamics Corp
Current assignee: General Dynamics Corp
Priority date: 1951-10-19
Filing date: 1951-10-19
Publication date: 1955-11-22
Anticipated expiration: 1972-11-22

Description

Nov. 22, 1955 c. SHERMAN BACK STOP FOR BOWLING ALLEY Filed Oct. 19. 1951 United States Patent BACK STOP FOR BOWLING ALLEY Kenneth Clark Sherman, Stonington, Conn, assignor, by mesne assignments, to General Dynamics (Iorporation, New York, N. Y., a corporation of Delaware Application October 19, 1951, Serial No. 252,107

11 Claims. (21. 273-s3 This invention relates to improvements in back stops such as are used in the pits at the rear end of bowling alleys to receive the impact of balls which have been bowled and of pins which have been knocked across the pit by bowled balls. It is an object of the invention to provide a back stop structure which is very durable, which does not vary in its manner of functioning, and which can be readily modified to have the particular characteristics desired for any particular variety of bowling game. For example, in one type of game if a hard-hit pin strikes the back stop and bounces back onto the alley in such a Way as to knock down another pin, that other pin or pins so knocked down must be replaced on the alley before the next ball is bowled, whereas in another type of game all fallen pins are counted including those which are knocked down by pins bouncing back from the back stop.

A further object of the invention is to provide a back stop which is substantially thinner than the customary structure. This feature may be of great value in cases where it is desired to install in an alley a pin-setting apparatus which includes a mechanism for mechanically retrieving the bowled balls and fallen pins from the pit. It often happens that when alleys are built, the back stops are practically against the wall of the building in which the alleys are located. Since the rules require that the front face of the back stop he thirty inches from the rear end of the alley, the substitution of a back stop having a thickness several inches less than that of the conventional back stopnow in use provides precious inches back of the back stop for the installation of mechanism for elevating balls and pins from the pit.

According to the invention, a back stopis provided which has an upper portion, roughly half, differing from the lower portion, the upper portion being designed to receive the impact of hard-hit pins which fly across the pit with a horizontal or rising flight. The lower portion of the back stop is designed to receive the impact of the bowled balls and such of the pins as may be knocked across the pit in a descending path.

The upper portion of the improved back stop includes a rigid plate having a resilient front face. The lower portion includes a thick sheet of rubber or the like which is flexible and is secured to the bottom edge of the rigid plate. In front of both plate and sheet hang a series of thin, flexible sheets of suitable tough material such, for example, as canvas. The upper parts of the sheets may, if desired, be stitched together, but the lower parts hang free with thin air spaces between successive sheets to act as air cushions in helping to absorb the kinetic energy of the balls which strike the back stop.

The back stop may be supported by being hung from a shelf in the usual manner or by being secured by fastening elements to the side walls of the alley pit. The choice of support will depend on the degree of rebound desired for pins which strike the upper portion of the back stop. A rigid mounting of the plate will result in a greater rebound of pins which hit it.

For a more complete understanding of the invention, reference may be had to the following description thereof and to the drawing, of which Figure 1 is a partial sectional view of a bowling alley including an embodiment of the invention;

Figure 2 is a front elevation of the invention from the direction indicated by the line 2-2 of Figure 1;

Figure 3 is a section on the line 3-3 of Figure 2, on a larger scale;

Figure 4 is a fragmentary section on the line 44 of Figure 3;

Figure 5 is a fragmentary horizontal section on the line 55 of Figure 3;

Figure 6 is a section somewhat similar to Figure 3, of a modified form of the invention;

Figure 7 is a fragmentary horizontal section on the line 7-'7 of Figure 6; and

Figure 8 is a fragmentary section on the line 8-8 of Figure 6.

The rear portion of a bowling-alley 10 is illustrated in Figure 1, together with a pit 12' in which bowled balls and fallen pins are disposed. The back wall of the alley is indicated at 14. A heavy plank shelf 16 customarily projects forward from the back wall between the side walls or kickbacks i8 and 24) of the alley. A back stop or pad is customarily suspended from the under face of the shelf 16 to receive the impact of bowled balls and of pins which are knocked from the alley and across the pit. This pad heretofore has usually consisted of a rectangular board or frame to the front face of which is secured a thick padding of any suitable material with a cover of leather, canvas or the like to hold the padding in place. According to the present invention a back stop is provided which comprises a rigid plate 22 suspended by eyes 24 from loops 26 which project downward from the under face of the shelf 16. The plate 22 may be of any suitable material such, for example, as aluminum, steel, or wood. To the front face of this plate is secured a facing layer 30 of resilient material such as soft rubber, this layer being of substantial thickness so as to provide resilience to cause a rebound 0n the part of the pins which may strike the plate area of the back-stop. The height of the plate is a little more than half the total height of the back stop.

The lower portion of the back stop comprises a flexible sheet 32 of soft rubber or the like, this sheet being of considerable weight and thickness. In order to reinforce the lower margin of the sheet 32, a transverse bar 34 of magnesium or other suitable material is secured to the rear face of the sheet near its lower edge.

A plurality of thin flexible sheets 36 hang down in front of and adjacent to the front 30 of the plate 22 and the heavy sheet 32. The sheets 36 may be of any suitable material such as canvas, each she-et being suspended from its upper margin which is secured to the upper margin of the plate 22. The bottom edges of the sheets 36 are preferably hemmed as at 38 so that the lower portions of the successive sheets are slightly spaced from each other. Each sheet has a rectangular area of approximately the same size as the combined shape and area of the plate 22 and heavy sheet 32. If desired, the upper portions of the sheets 36 which cover the plate area of the back-stop may be secured together by quilt stitching, as indicated at 40 in Figures 5 and 7. The lower portions of the sheets 36 are not connected in any way but hang independently. The front sheet 42 is preferably not stitched to the other sheets but hangs freely from its upper margin.

In order to add to the inertia of the back stop as a whole when it is mounted to swing at its upper edge, as indicated in Figure 3, an inertia member 46 may be hung edgewise from the shelf 16 immediately behind the plate 22. This inertia member 46 may conveniently be in the form of a rectangular plate of metal, such as steel, of sufficient thickness to give the desired added inertia so that when the back stop is struck by a flying pin, it will not-be swung too far back as a result of the impact. In order to prevent clashing between the plate 22 and the inertia member 46, I provide suitable cushions between these two members, the cushions being mounted on either one or the other as found convenient. As shown, the cushions consist of two or more vertical strips 50 of rubber or other resilient material which are fastened by cement orotherwise to the rear face of the plate 22, one strip being provided for each side margin of the plate 22. The freedom of the back stop to swing results in the absorption of a considerable portion of the kinetic energy of rapidly moving pins and balls which strike the back stop by the conversion of some of this kinetic energy into swinging movement of the back stop, such movement being checked by the inertia of the backing member 46.

In case the back stop is to be mounted in an alley which is to be used for a game permitting pins to be knocked down by other pins rebounding from the back stop, greater rebound may be had by rigidly mounting the plate 22 so that it will not yield at all. This may be done as indicated in Figure 6 by providing a plate 52 which is similar to the plate 22 except that it has a flange 54 extending around its periphery and may also have reinforcing ribs 55, the plate being of suflicient size to fit between the kickbacks 18 and 20 so that it can be firmly secured thereto and to the shelf 16 by lag screws or other suitable fastening elements. The heavy rubber sheet 32 is preferably suspended from an inertia plate 46 instead of from the fixed plate 52. Thin flexible sheets 36 may be suspended from their upper margins as hereinbefore described so as to hang down in front of and adjacent to the plate 52 and the heavy sheet 32. The upper portions of these sheets, except for the outermost, may be quilt stitched as indicated at 40 in Figure 7.

Without limiting myself to any particular dimensions, I have found that a plate 22 which is /1 inch thick is suitable for the purpose, such plate having a facing layer of rubber inch thick. The heavy flexible sheet 32 may be from /1 inch to an inch in thickness. The height of the plate 22 is preferably about 18 inches, the height of the rubber sheet 32 being approximately inches with an overlap of approximately 2 /2 inches. If the

flexible sheets

36 and 42 are of canvas, it is preferable to employ at least 10 such sheets and sometimes a few more. The stiffening strip 34 may be of any suitable material such as magnesium and may be two inches wide and inch thick. This strip stitfens the lower corners of the heavy sheet 32 so as to prevent rapidly moving balls from bending back a lower corner and passing beyond the back stop. It is to be understood, however, that the foregoing dimensions, and materials, are given by way of illustration only and may be varied as may be found desirable without departing from the scope of the invention defined in the following claims.

I claim:

1. A bowling alley back-stop comprising a rigid rectangular plate with a front facing of resilient material, a heavy flexible sheet secured to the lower edge of said plate and depending therefrom, and a plurality of thin flexible sheets in front of said plate and heavy sheet and secured along their upper margins to the upper margin of said plate.

2. A bowling alley back-stop as in claim 1, some of said thin flexible sheets being of canvas.

3. A bowling alley back-stop as in claim 1, some of said thin flexible sheets having hems along their bottom edges.

4. A bowling alley back-stop as in claim 1,- some of said thin flexible sheets having the portions thereof which overlie said plate joined together by quilt stitching, the lower portions of said sheets hanging independently.

5. A bowling alley back-stop comprising a rigid rectangular plate with a front facing of resilient material, a heavy flexible sheet depending from the lower edge of said plate, an elongated stiffening element secured to said sheet near the bottom edge thereof, and a plurality of thin flexible fabric sheets hanging in front of and adjacent to said plate and heavy sheet, said thin sheets being secured along their upper margin to said plate and extending sub.- stantially from the top margin of said plate to thebottom edge of said heavy sheet.

6. A bowling alley back-stop comprising a rigid rec.- tangular plate swingably suspended at its upper edge, a layer of resilient material overlying the front face of said plate, a rectangular sheet of heavyrubber hanging from the lower margin of said plate, an elongated stiffening element secured to said rubber sheet along the lower margin thereof, a plurality of thin flexible sheets secured along their upper margins to the upper margin of the plate, and an inertia member swingably suspended immediately behind said plate.

7. A bowling alley back-stop as in claim 6, said inertia member being a heavy metal plate suspended edgewise.

8. A bowling alley back-stop as in claim 6, and cushion elements mounted between said plate and inertia member.

9. A bowling alley back-stop comprising a rigid rectangular plate having a substantial layer of soft rubber secured to its front face, means supporting said plate in a vertical plane, an inertia plate swingably supported edgewise behind and parallel to said rigid plate, and a heavy flexible sheet suspended edgewise from one of said plates.

10. Apparatus-as in claim 9, and a plurality of thin flexible sheets suspended edgewise in front of and against said rigid plate.

11. A bowling alley back-stop comprising a rigid rectangular plate having a substantial layer of soft rubber secured to and covering the front face thereof, a thick sheet of soft rubber depending from the'lower margin of said plate, a metal stiffening bar secured to said rubber sheet along the lower margin thereof, a plurality of canvas sheets having their upper margins secured to the upper margin of said plate and their lower edges substantially on a level with the lower edge of said rubber sheet.

References Cited in the file of this patent UNITED STATES PATENTS 714,970 Talbert Dec. 2, 1902 720,533 Mellen Feb. 10, 1903 1,035,658 Talbert Aug. 13, 1912 1,976,932 Forsberg Oct. 16, 1934 2,531,167 Simpson Nov. 21, 1950