US3248110A - Instantaneous backstop elevating apparatus - Google Patents
Instantaneous backstop elevating apparatus Download PDFInfo
- Publication number
- US3248110A US3248110A US256890A US25689063A US3248110A US 3248110 A US3248110 A US 3248110A US 256890 A US256890 A US 256890A US 25689063 A US25689063 A US 25689063A US 3248110 A US3248110 A US 3248110A
- Authority
- US
- United States
- Prior art keywords
- backstop
- elevating
- pit floor
- cylinder
- ball
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63D—BOWLING GAMES, e.g. SKITTLES, BOCCE OR BOWLS; INSTALLATIONS THEREFOR; BAGATELLE OR SIMILAR GAMES; BILLIARDS
- A63D5/00—Accessories for bowling-alleys or table alleys
- A63D5/02—Apparatus for trapping or lifting the balls; Separate devices for returning the balls
Definitions
- This invention relates to apparatus for elevating a backstop, and more particularly to apparatus responsive the backstop usually includes a cam arrangement which is timed in with the pin-spotting cycle of the pinspot'ter equipment. Hence, it is normal in this arrangement to have a delay in the elevation of the backstop, and hence, a delay in the return of the bowling ball to the player. This delay normally is in the range of 1 to 4 seconds.
- a further object of this invention is to provide backstop elevating apparatus which may be used in existing automatic pin-spotting equipment.
- Another object of this invention is to provide backstop elevating apparatus which is relatively inexpensive to manufacture and operate.
- Still another object of this invention is to provide backstop elevating apparatus which is reliable in operation.
- FIGURE 1 is an elevation view of the present backstop elevating apparatus, as used in the pit area of the bowling alley, with the backstop lowered into a ball
- FIGURE 2 is an elevation view, similar to FIG. 1, of the present backstop elevating apparatus but with the backstop in a raised position;
- FIGURE 3 is a schematic illustration of the control circuit of the present backstop elevating apparatus.
- a pit area which includes a pin deck 12,- a pit floor '14, a backstop 16, a curtain 18, a kickback 20 and kickback plate 22.
- the pit floor 14 is of the vibratory type and is sloped downwardly from the pin deck 12 toward the rear of the pit area 10.
- the pit floor 14, by virtue of its slope and vibratory motion, serves to convey the pins under the backstop 16 to the automatic pin-setting equipment and when it is raised as in FIG. 2, to convey bowling balls to the ball return equipment (not shown), respectively.
- the kickback 20 and the kickback plate 22 serve among other things to deflect flying Patented Apia-26, 1966 to be elevated vertically'w-ith respect to the pit floor 14.
- backstop 16 may be supported in vertically adjustable relation with the pit floor 14, it should be evident that any suitable means may be employed.
- a backstop elevating apparatus 30 is shown comprising elevating means 32 and switch means 34.
- the elevating means 32 preferably comprises a pneumatically operated cylinder 36 pivotally supported at its upper end by a hinge connection 38 which is secured to a suitable support structure.
- the cylinder 36 includes a shaft 40 having a first end 42 extending into the cylinder 36 and connected to a piston 44; and a second end 46 extending downwardly therefrom and connected to an angle member 48 which is rigidly secured to the backstop 16.
- the second end 46 of the shaft 40 preferably is connected to the angle member 48 in a manner which will permit the backstop 16 to be elevated by the existing backstop elevating mechanism of the automatic pin-spotting equipment independent of the elevating means 32. This is accomplished, in the present apparatus, by providing a nut on the second end 46 which is adapted to be engaged by the angle member 48 only from above. Notice, then, that the angle member 48 is free for vertical longitudinal movement with respect to the shaft 40.
- the present backstop elevating apparatus may be used in existing automatic pin-spotting equipment.
- a conduit 50 preferably of the flexible type, is connected to the cylinder 36 at a point below the piston 44.
- the conduit 50 serves to introduce and exhaust a working fluid, preferably comprising compressed air, from the interior of the cylinder 36 in a manner which will be described later in conjunction with FIG. 3.
- the switch means 34 preferably comprises a suitable electrical switch 52 rigidly supported on the structure of the pit area 10 and a switch operating means or probe 54 extending therefrom.
- the probe 54 comprises a rod slidably supported in a tube 56 which is rigidly secured to the structure of the pit area 10.
- the probe 54 preferably includes an enlarged end portion 58 engaged with a slide plate 60 secured to the back of the backstop 16.
- the slide plate 60 provides a smooth surface on which the enlarged end portion 58 will slide when the backstop -16 is elevated (see FIG. 2).
- the pneumatic and electrical control circuits of the backstop elevating means 32 are schematically illustrated in FIG. 3.
- Thepneumatic control circuit includes the conduit 50 extending from the cylinder 36 to one outlet ofa twoway valve 62; a supply conduit 64 extending from a second outlet of the two-way valve 62 to a source of working fluid schematically represented at 66; and a vent conduit 68 extending from a third outlet of the two-way valve 62.
- the two-Way valve 62 has a first position wherein the working fluid may be introduced into the cylinder 36 by way of conduits 50, 64; and a secondposition wherein the supply conduit 64 is sealed off and wherein the working fluid in the cylinder 36 may be vented to the atmosphere by way of conduits 50, 68.
- the coil 72 may be connected to the switch 52 through a second pair of contacts 78 which connect a time delay circuit80 into the control circuit.
- the time delay circuit 80 provides this slight delay. The selection of which pair of contacts, 76 or 78, is to be used is afforded by the manually operated pushbutton switch 82.
- the operation of the present backstop elevating apparatus is as follows.
- the manually operated pushbutton'switch 82 is positioned so that contacts 76 are used to directly connect the solenoid 70 Y to the switch. 52.
- the switch 52 will be closed to instantaneously energize the solenoid 70 whereupon the working fluid is communicated to the operating cylinder 36 to raise the backstop 16. Meanwhile, the ball 24' will drop to the position indicated at 24.
- the backstop 16 is raised, as shown in FIG. 2, the slope and vibratory motion of the pit floor 14 will convey the ball 24 under the backstop 16 to theball return mechanism.
- the manually operated pushbutton switch 82 When a slight delay isrequired in the elevation of the backstop 16, the manually operated pushbutton switch 82 is depressed 'to connect the contacts 78 which interpose the time delay circuit 80 into the control circuit. Thus, when the ball 24 hits the backstop 16, theswitch 52 will be closed. However, since the time delay circuit 80 is operative in this circuit, a very slight delay will occur before the energization of the solenoid 70. When the solenoid 70 is energized, the working fluid is communicated to the operating cylinder 36 to raise the backstop 16'. Meanwhile, the ball 24' will drop to the position indicated at 24 and the slight delay provided by the time delay circuit 80 will permit the ball 24'to be engaged with the backstop 16 preparatory to its passing thereunder. When the backstop 16 is raised, as shown in FIG. 2, the mechanized pit floor 14 will convey the ball 24 under the backstop 16 to the ball return mechanism.
- a backstop suspended above a adjustable relation therewith; elevating means for rapidly elevating said backstop pit floor in vertically a fluid operated cylinder pivotallysupported at one end to extrinsic support structure and a piston shaft extending from said cylinder and connected to said backstop; switch means actuable by the impact of a bowling ball with said backstop; and v circuit means responsive to the actuation of said switch means for energizing said elevating means whereby said backstop is elevated immediately to permit said bowling ball to pass.
- elevating means for rapidly elevating said backstop above said pit floor, comprising a fluid operated cylinder means pivotally supported at one end to extrinsic support structure and piston shaft extending therefrom and connected to said backstop;
- switch means actuable by the impact of a bowling ball with said backstop, said switch means including a switch operating probe connecting said backstop directly with said switch means;
- circuit means responsive-to the actuation of said switch means for energizing said elevating means whereby said backstop is elevated immediately to permit said bowling ball to pass.
- elevating means for rapidly elevating said backstop above said pit floor comprising a fluid operated cylin- P der pivotally supported at one end to extrinsic support structure and a piston shaft extending therefrom and connected to said backstop;
- conduit means connecting said source of pressurized fluid with said cylinder
Landscapes
- Jib Cranes (AREA)
Description
A ril 26, 1966 E. c. WEEB INSTANTANEOUS BACKSTOP ELEVATING APPARATUS Filed Feb. '2, 1963 INVENTOR.
E/P/VEST CT WEBB 7M deflecting position;
United States Patent 3,248,110 INSTANTANEOUS BACKSTOP ELEVATING APPARATUS Ernest C. Webb, Bay Village, Ohio, assignor to Lakewood Manufacturing Company, Westlake, Ohio, at corporation of Ohio Filed Feb. 7, 1963, Ser. No. 256,890
3 Claims. (Cl. 273-49) This invention relates to apparatus for elevating a backstop, and more particularly to apparatus responsive the backstop usually includes a cam arrangement which is timed in with the pin-spotting cycle of the pinspot'ter equipment. Hence, it is normal in this arrangement to have a delay in the elevation of the backstop, and hence, a delay in the return of the bowling ball to the player. This delay normally is in the range of 1 to 4 seconds.
It is a primary object of this invention to provide a backstop elevating apparatus which will instantaneously elevate the backstop thereby decreasing the time involved in returning the bowling ball to the player.
It is another object of this invention to provide backstop elevating apparatus which is responsive to the impact of a bowling ball with the backstop for instantaneously elevating the backstop.
A further object of this invention is to provide backstop elevating apparatus which may be used in existing automatic pin-spotting equipment.
Another object of this invention is to provide backstop elevating apparatus which is relatively inexpensive to manufacture and operate.
Still another object of this invention is to provide backstop elevating apparatus which is reliable in operation.
These and other objects and advantages of the present invention will become apparent from the following detailed description by reference to the accompanying drawings, and in which:
FIGURE 1 is an elevation view of the present backstop elevating apparatus, as used in the pit area of the bowling alley, with the backstop lowered into a ball FIGURE 2 is an elevation view, similar to FIG. 1, of the present backstop elevating apparatus but with the backstop in a raised position; and
FIGURE 3 is a schematic illustration of the control circuit of the present backstop elevating apparatus.
Referring to 'FIG. 1, a pit area is shown which includes a pin deck 12,- a pit floor '14, a backstop 16, a curtain 18, a kickback 20 and kickback plate 22.
In this illustration, the pit floor 14 is of the vibratory type and is sloped downwardly from the pin deck 12 toward the rear of the pit area 10. The pit floor 14, by virtue of its slope and vibratory motion, serves to convey the pins under the backstop 16 to the automatic pin-setting equipment and when it is raised as in FIG. 2, to convey bowling balls to the ball return equipment (not shown), respectively. The kickback 20 and the kickback plate 22 serve among other things to deflect flying Patented Apia-26, 1966 to be elevated vertically'w-ith respect to the pit floor 14.
Although a specific means has been illustrated by which the backstop 16 may be supported in vertically adjustable relation with the pit floor 14, it should be evident that any suitable means may be employed.
A backstop elevating apparatus 30 is shown comprising elevating means 32 and switch means 34.
The elevating means 32 preferably comprises a pneumatically operated cylinder 36 pivotally supported at its upper end by a hinge connection 38 which is secured to a suitable support structure. The cylinder 36 includes a shaft 40 having a first end 42 extending into the cylinder 36 and connected to a piston 44; and a second end 46 extending downwardly therefrom and connected to an angle member 48 which is rigidly secured to the backstop 16. The second end 46 of the shaft 40 preferably is connected to the angle member 48 in a manner which will permit the backstop 16 to be elevated by the existing backstop elevating mechanism of the automatic pin-spotting equipment independent of the elevating means 32. This is accomplished, in the present apparatus, by providing a nut on the second end 46 which is adapted to be engaged by the angle member 48 only from above. Notice, then, that the angle member 48 is free for vertical longitudinal movement with respect to the shaft 40. Hence, the present backstop elevating apparatus may be used in existing automatic pin-spotting equipment.
A conduit 50, preferably of the flexible type, is connected to the cylinder 36 at a point below the piston 44. The conduit 50 serves to introduce and exhaust a working fluid, preferably comprising compressed air, from the interior of the cylinder 36 in a manner which will be described later in conjunction with FIG. 3.
The switch means 34 preferably comprises a suitable electrical switch 52 rigidly supported on the structure of the pit area 10 and a switch operating means or probe 54 extending therefrom. The probe 54 comprises a rod slidably supported in a tube 56 which is rigidly secured to the structure of the pit area 10. The probe 54 preferably includes an enlarged end portion 58 engaged with a slide plate 60 secured to the back of the backstop 16. The slide plate 60 provides a smooth surface on which the enlarged end portion 58 will slide when the backstop -16 is elevated (see FIG. 2).
The pneumatic and electrical control circuits of the backstop elevating means 32 are schematically illustrated in FIG. 3.
Thepneumatic control circuit includes the conduit 50 extending from the cylinder 36 to one outlet ofa twoway valve 62; a supply conduit 64 extending from a second outlet of the two-way valve 62 to a source of working fluid schematically represented at 66; and a vent conduit 68 extending from a third outlet of the two-way valve 62. The two-Way valve 62 has a first position wherein the working fluid may be introduced into the cylinder 36 by way of conduits 50, 64; and a secondposition wherein the supply conduit 64 is sealed off and wherein the working fluid in the cylinder 36 may be vented to the atmosphere by way of conduits 50, 68.
The positions of the two-way -valve 62, that is, supplying 52 will instantaneously energize the solenoid 70 to raise the backstop 16. p
It is sometimes desirable to have a very slight delay between the closing of the switch 52 and the energization of the solenoid 70 for raising the backstop 16. Alternatively then, the coil 72 may be connected to the switch 52 through a second pair of contacts 78 which connect a time delay circuit80 into the control circuit. The time delay circuit 80 provides this slight delay. The selection of which pair of contacts, 76 or 78, is to be used is afforded by the manually operated pushbutton switch 82.
'When an instantaneous elevation of the backstop16 is desired, the operation of the present backstop elevating apparatus is as follows. The manually operated pushbutton'switch 82 is positioned so that contacts 76 are used to directly connect the solenoid 70 Y to the switch. 52. Thus, when a ball 24', illustrated in phantom outline in FIG. 1, hits the backstop 16, the switch 52 will be closed to instantaneously energize the solenoid 70 whereupon the working fluid is communicated to the operating cylinder 36 to raise the backstop 16. Meanwhile, the ball 24' will drop to the position indicated at 24. When the backstop 16 is raised, as shown in FIG. 2, the slope and vibratory motion of the pit floor 14 will convey the ball 24 under the backstop 16 to theball return mechanism.
When a slight delay isrequired in the elevation of the backstop 16, the manually operated pushbutton switch 82 is depressed 'to connect the contacts 78 which interpose the time delay circuit 80 into the control circuit. Thus, when the ball 24 hits the backstop 16, theswitch 52 will be closed. However, since the time delay circuit 80 is operative in this circuit, a very slight delay will occur before the energization of the solenoid 70. When the solenoid 70 is energized, the working fluid is communicated to the operating cylinder 36 to raise the backstop 16'. Meanwhile, the ball 24' will drop to the position indicated at 24 and the slight delay provided by the time delay circuit 80 will permit the ball 24'to be engaged with the backstop 16 preparatory to its passing thereunder. When the backstop 16 is raised, as shown in FIG. 2, the mechanized pit floor 14 will convey the ball 24 under the backstop 16 to the ball return mechanism.
Although the invention has been shown in connection with a certain specific embodiment, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention,
I claim as my invention:
1. In apparatus for momentarily elevating a backstop suspended above the pit floor of a bowling alley, the combination comprising:
a backstop suspended above a adjustable relation therewith; elevating means for rapidly elevating said backstop pit floor in vertically a fluid operated cylinder pivotallysupported at one end to extrinsic support structure and a piston shaft extending from said cylinder and connected to said backstop; switch means actuable by the impact of a bowling ball with said backstop; and v circuit means responsive to the actuation of said switch means for energizing said elevating means whereby said backstop is elevated immediately to permit said bowling ball to pass.
2. In apparatus for momentarily elevating a backstop suspended above the pit floor of a bowling alley, the combination comprising:
a backstop suspended above a pit floor in vertically.
adjustable relation therewith;
elevating means for rapidly elevating said backstop above said pit floor, comprising a fluid operated cylinder means pivotally supported at one end to extrinsic support structure and piston shaft extending therefrom and connected to said backstop;
switch means actuable by the impact of a bowling ball with said backstop, said switch means including a switch operating probe connecting said backstop directly with said switch means; and
circuit means responsive-to the actuation of said switch means for energizing said elevating means whereby said backstop is elevated immediately to permit said bowling ball to pass. 7
3. In apparatus for momentarily elevating a backsto suspended above the pit floor of a bowling alley, the combination comprising:
a backstop suspended above a pit floor in vertically adjustable relation therewith; elevating means for rapidly elevating said backstop above said pit floor, comprising a fluid operated cylin- P der pivotally supported at one end to extrinsic support structure and a piston shaft extending therefrom and connected to said backstop;
a source of pressurized fluid;
conduit means connecting said source of pressurized fluid with said cylinder;
unitary valve means in said conduit means for com-' References Cited by the Examiner UNITED STATES PATENTS 2,621,930 12/1952 Mead 27342 2,705,146 3/1955 Montooth et al 273-43 2,890,886 6/1959 Dumas 273-43 -2,9' 73,204 2/1961 Huck 6t al. 273-43 2,99 1 ,078 7/ 1961 Hedenskoog et al. 273-43 RICHARD C. PINKHAM, Primary Examiner.- DELBERT B. LOWE, Examiner.
Claims (1)
1. IN APPARATUS FOR MOMENTARILY ELEVATING A BACKSTOP SUSPENDED ABOVE THE PIT FLOOR OF A BOWLING ALLEY, THE COMBINATION COMPRISING: A BACKSTOP SUSPENDED ABOVE A PIT FLOOR INVERTICALLY ADJUSTABLE RELATION THEREWITH; ELEVATING MEANS FOR RAPIDLY ELEVATING SAID BACKSTOP ABOVE SAID PIT FLOOR, SAID ELEVATING MEANS COMPRISING A FLUID OPERATED CYLINDER PIVOTALLY SUPPORTED AT ONE END TO EXTRINSIC SUPPORT STRUCTURE AND A PISTON SHAFT EXTENDING FROM SAID CYLINDER AND CONNECTED TO SAID BACKSTOP; SWITCH MEANS ACTUABLE BY THE IMPACT OF A BOWLING BALL WITH SAID BACKSTOP; AND
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US256890A US3248110A (en) | 1963-02-07 | 1963-02-07 | Instantaneous backstop elevating apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US256890A US3248110A (en) | 1963-02-07 | 1963-02-07 | Instantaneous backstop elevating apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3248110A true US3248110A (en) | 1966-04-26 |
Family
ID=22974024
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US256890A Expired - Lifetime US3248110A (en) | 1963-02-07 | 1963-02-07 | Instantaneous backstop elevating apparatus |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3248110A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3375006A (en) * | 1965-08-12 | 1968-03-26 | Quick Ball Return Inc | Mechanical backstop for pin setting machines |
| US3790167A (en) * | 1972-07-03 | 1974-02-05 | Zot Mfg Co | Control system and cushion mount for bowling machines |
| US4239234A (en) * | 1979-01-23 | 1980-12-16 | Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National Defence | Pneumatic target system |
| US4530501A (en) * | 1983-07-01 | 1985-07-23 | Eastern Bowling Equipment Company | Conversion apparatus for bowling pin setting machine |
| US4540182A (en) * | 1983-03-23 | 1985-09-10 | Clement Tommy G | Power operated targets for shooting ranges |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2621930A (en) * | 1948-05-08 | 1952-12-16 | Theodore E Mead | Power-actuated pin-setting apparatus |
| US2705146A (en) * | 1948-03-11 | 1955-03-29 | Brunswick Balke Collender Co | Control circuit for a pin setting machine |
| US2890886A (en) * | 1954-02-24 | 1959-06-16 | American Mach & Foundry | Bowling pin spotting machine control mechanism |
| US2973204A (en) * | 1955-11-25 | 1961-02-28 | Brunswick Automatic Pinsetter | Automatic pinsetter |
| US2991078A (en) * | 1953-08-04 | 1961-07-04 | Brunswick Automatic Pinsetter | Completely automatic pin setting and ball return mechanism for bowling alley |
-
1963
- 1963-02-07 US US256890A patent/US3248110A/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2705146A (en) * | 1948-03-11 | 1955-03-29 | Brunswick Balke Collender Co | Control circuit for a pin setting machine |
| US2621930A (en) * | 1948-05-08 | 1952-12-16 | Theodore E Mead | Power-actuated pin-setting apparatus |
| US2991078A (en) * | 1953-08-04 | 1961-07-04 | Brunswick Automatic Pinsetter | Completely automatic pin setting and ball return mechanism for bowling alley |
| US2890886A (en) * | 1954-02-24 | 1959-06-16 | American Mach & Foundry | Bowling pin spotting machine control mechanism |
| US2973204A (en) * | 1955-11-25 | 1961-02-28 | Brunswick Automatic Pinsetter | Automatic pinsetter |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3375006A (en) * | 1965-08-12 | 1968-03-26 | Quick Ball Return Inc | Mechanical backstop for pin setting machines |
| US3790167A (en) * | 1972-07-03 | 1974-02-05 | Zot Mfg Co | Control system and cushion mount for bowling machines |
| US4239234A (en) * | 1979-01-23 | 1980-12-16 | Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National Defence | Pneumatic target system |
| US4540182A (en) * | 1983-03-23 | 1985-09-10 | Clement Tommy G | Power operated targets for shooting ranges |
| US4530501A (en) * | 1983-07-01 | 1985-07-23 | Eastern Bowling Equipment Company | Conversion apparatus for bowling pin setting machine |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3248110A (en) | Instantaneous backstop elevating apparatus | |
| IT8348587A1 (en) | PROCEDURE AND EQUIPMENT FOR CARRYING OUT A HYDRAULIC PRESSURE TEST ON A PIPE. | |
| US2019607A (en) | Automatic ball return for bowling alleys | |
| US3790167A (en) | Control system and cushion mount for bowling machines | |
| US2365147A (en) | Riveting machine | |
| US5630759A (en) | Device used with billiard table for sensing balls dropping into the pockets and scoring as well as collecting and arranging the ball | |
| US3138378A (en) | Automatic pinspotter spare practice device having selectively deactivated respottingunits | |
| US2295925A (en) | Multiple spot welder | |
| US3105684A (en) | Automatic apparatus for segregating returned bowling balls | |
| US3120956A (en) | Manually or automatically illuminated bowling guide | |
| US3123356A (en) | Spare selector apparatus and method for setting less | |
| US3215433A (en) | Control system for returning bowled balls to selected racks | |
| US2551023A (en) | Ball transfer mechanism for ball games | |
| GB1030192A (en) | Bowling lane signalling mechanism | |
| US3331603A (en) | Spring driven bowling ball propelling mechanism | |
| US2672340A (en) | Bowling pin setting mechanism | |
| US2621930A (en) | Power-actuated pin-setting apparatus | |
| US2210398A (en) | Bowling game | |
| US2967055A (en) | Individual pin spotter for bowling alleys | |
| US2611611A (en) | Bowling pin respotter | |
| US2329992A (en) | Golf yardage registering device | |
| US3411780A (en) | Automatic pinsetter circuit | |
| US2682404A (en) | Bowling ball return | |
| US2207206A (en) | Junior bowling game | |
| US1597974A (en) | Pin-setting machine for bowling alleys |