US3652088A

US3652088A - Tethered ball baseball batting practice device

Info

Publication number: US3652088A
Application number: US868095A
Authority: US
Inventors: Loyal F Marsh
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-10-21
Filing date: 1969-10-21
Publication date: 1972-03-28
Anticipated expiration: 1989-03-28

Abstract

A baseball or softball batting practice device has a rope trackway along which a pulley carriage is adapted to travel freely. A simulated baseball or softball is suspended by a length of nylon cord from the carriage. A batter strikes the ball to cause the carriage to travel along the trackway and endeavors to hit the ball again as the carriage returns toward the batter along the trackway. In a preferred embodiment the ball has a solid cork center core and a molded urethane elastomer shell surrounding the cork core. One end of the nylon cord extends through and is wrapped once about the core and embedded in the urethane shell.

Description

[451 Mar. 28, 1972 United States Patent Marsh 7 n" 2 knflm "00m oh d mm o-l. DNPZW 29934 66635 99999 HHHH M7756 1 00522 797 2 ,923 92470 655000 2 2 333 2 [22] Filed:

Primary Examiner-Richard C. Pinkham Assistant Examiner-Theatrice Brown [2]] Appl. No.:

Attorney-Buckhorn, BLore, Klarquist and Sparkman [52] US. Cl. ...................273/26 E, 273/DIG. l, 273/DIG. 2,

273/DIG. 4, 273/DlG. 5, 273/DIG. 6, 273/DIG. 8, ABSTRACT 273/DIG. 10,273/DIG. 12,273/DIG. 15,273/DIG. A baseball or softball batting practice device has a ro trackway along which a pulley carria freely. A simulated baseball or soft ge is adapted to travel 16, 273/58 C ....A63b69/40 .273/26, 95 A, 200 A, 58 A,

ball is suspended by a [58] Field of length of nylon cord from the carriage. A batter strikes the ball to cause the carriage to travel along the trackw deavors to hit the ball again as the carria ay and enge returns toward the 273/58 BA, 58 C, DIG. 8

References Cited batter along the trackway. In a preferred embodiment the ball has a solid cork center core and a molded urethane elastomer shell surrounding the cork core. One end of the n ylon cord excore and em- UNITED STATES PATENTS tends through and is wrapped once about the bedded in the urethane shell.

1,502,058 Quinn 2,086,094 7/1937 Reach..... 2,242,455 5/1941 De Beer......

8 Claims, 3 Drawing Figures RUBBER OR RESILIENT PLASTIC CORK OR RESILIENT PLASTIC TETI-IERED BALL BASEBALL BATTING PRACTICE DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a baseball or softball batting practice device including an inclined rope trackway and a ball suspended by a line from a carriage freely movable along the trackway. The invention more particularly relates to a ball construction for use with such a device.

2. Description of Prior Art Although baseball batting practice devices of the aforemen tioned general type have been suggested, they are not in common use. A principal reason for their lack of acceptance is thought to reside in the inability of the balls of such devices to withstand the great physical abuse which they receive from repeatedly being struck with a bat. Another probable reason is the lack of a suitable means for attaching the suspension cord to the ball in a manner so that the ball and cord remain intact under repeated usage.

SUMMARY OF THE INVENTION The present invention overcomes the deficiencies of the prior art by providing a batting practice device of the general type mentioned in which the simulated baseball or softball has a solid cork or hollow plastic center and a molded elastomer main outer body portion surrounding the core. This combination of materials has been found to withstand the severe pounding which such a ball undergoes.

Also in accordance with the invention the cord suspending the ball from the carriage is permanently attached to the ball by extending an end portion of the cord through the core and then wrapping it at least once around such core and embedding the wrapped portion of the cord in the molded outer material.

Principal objects of the invention are to provide:

1. a batting practice device of the general type described having a simulated baseball or softball that withstands repeated severe poundings without deterioration;

2. a batting practice device as aforesaid having a simulated baseball or softball that does not separate from its suspension cord; and

3. a ball as aforesaid which is economical to produce.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects and advantages of the invention will become more apparent from the following detailed description which proceeds with reference to the accompanying drawings wherein:

FIG. I is a schematic view of a batting practice device in ac cordance with the invention;

F IG. 2 is an enlarged vertical sectional view through the ball of the batting practice device of FIG. 1; and

FIG. 3 is a horizontal section taken along the line 3-3 of FIG. 2.

DETAILED DESCRIPTION General Arrangement With reference to FIG. 1 of the drawings the batting practice device includes an inclined rope trackway anchored at its lower ends to a ground stake 12 and at its upper end to a tree, side of a house, or standard 14 or the like. A wheel-supported carriage 16 is mounted to travel freely along the rope trackway. The carriage is limited in its upward and downward travel along the trackway by screw-type stops 18, 20, both of which may be placed at various positions along the trackway. A cord 22 made of nylon or other suitable high-strength material suspends a simulated baseball or softball 24 from carriage 16.

In using the device the batter stands near the lower limit of travel of the ball and bats the ball in a direction toward the upper end of trackway l0, whereupon the ball and carriage ascend the trackway. After striking stop 20, the carriage and ball descend the trackway under the influence of gravity. As the ball again approaches the batter, he swings again and attempts again to hit the ball up the trackway. In this manner the device develops the batter's skill in hitting the moving ball.

A suitable material for the rope trackway is a vinyl-clad cotton rope of approximately A-inch diameter which minimizes friction. Of course, other suitable rope materials could also be used.

Carriage 16 includes a carriage body portion 160 which rotatably mounts a carriage wheel 16b which engages an upper portion of the trackway 10. If desired a second pulley wheel (not shown) could be mounted within the carriage casing 16a below wheel 16b and the rope trackway to increase the stability of the carriage in its travel.

Ground stake 12 preferably should be 3 feet or more in length to securely anchor the lower end of the trackway 10. The trackway itself may be 50 to feet in length, depending upon the space available for use. It has been found that a rope inclination of between 30 and 40 from the horizontal should be used, with an inclination of about 35 giving the best results.

Suspension cord 22 is at least about 2 feet in length to provide the necessary clearance between the ball 24 and the trackway when the batter swings at the ball. The cord may be covered by a tubular plastic sheath (not shown) for protection.

The trackway can also be suspended horizontally if desired, to enable two batters at opposite ends of the trackway to hit the ball back and forth.

If desired, the opposite ends of the trackway may be provided with suitable quick connector means such as clips to facilitate rapid assembly and disassembly of the trackway.

Construction of Ball It has been found that an ordinary baseball or softball does not withstand for long the repeated pounding which the ball receives when used in the manner described. Difficulties have also been encountered in attaching an ordinary baseball, softball or other ball to suspension cord 22 in a manner so that the ball remains attached to the cord for long repeated usage of the device.

Accordingly I have developed a special type of simulated baseball or softball that has been found to outlast conventional softballs and baseballs when used with the practice device. I have also developed a means for attaching the ball to its suspension cord that retains the ball on its cord under repeated hard usage.

The ball of my invention, as shown most clearly in FIGS. 2 and 3, includes an inner core 30, preferably formed of a solid cork material. A homogenous outer shell or body portion 26 surrounds the core and receives the impact of a bat. Body portion 26 is made of a molded elastomer material such as rubber or a resilient plastic.

Cord 22 is connected to ball 24 by extending an end portion 32 of the cord through a center opening in core 30, wrapping end 32 at least once around the periphery of the core, and stapling or otherwise affixing the extreme end of the cord to core 30 with a staple 28 or other suitable fastener. Then the core wrapping is embedded in outer shell 26 by pouring and molding the shell about the preassembled core and wrapping. The result is an extremely durable simulated ball 24 having a substantially permanent connection to suspension cord 22.

Ball 24 is made in a size and weight approximating the size and weight of a conventional baseball or softball to be simulated. The weight of the ball can be accurately controlled by controlling the size of the center core.

EXAMPLE Urethane has been found to be a highly satisfactory material for use as the elastomer shell. For example, in manufacturing a satisfactory shell of this material, 15 parts of DuPont Adiprene L-100 were mixed with 1 part DuPont Moca" catalyst. A catalyst in the ratio described enables curing of the shell at room temperature. The ball was made according to the following procedure:

A Sir-inch nylon cord was used as the suspension cord. One end of this cord was first stapled to a spherical cork core and then wrapped once around the core. Then the free end of the cord was threaded through a center opening in the core and extended outwardly of an epoxy mold for the ball. The assembled core and wrapping was centered on a pin support within the mold. Then the liquid urethane mixture was evacuated of air bubbles, and poured under atmospheric pressure into the mold at a temperature of between 200 and 250 F. It is, of course, important that the temperature of the urethane or other casting material be maintained below the melting point of the cord. The urethane was then permitted to cure at room temperature.

The shell could also be compression-molded about the core and wrapping. A metal mold would be used. The liquid urethane would be injected into the mold under a pressure of approximately 20,000 p.s.i. and temperature of between 240 and 250 F. In compression-molding the shell as described, the preliminary step of evacuating the liquid under a subatmospheric pressure could be eliminated.

Other suitable elastomer materials for the outer shell would include natural rubber (natural polyisoprene), synthetic rubber (synthetic polyisoprene), styrene butadiene rubber, isobutyiene isoprene rubber, polybutadiene rubber, ethylene propylene rubber, neoprene (chloroprene) rubber, acrylonitrile butadiene rubber, polyethylene, polypropylene, and ethyl vinyl acetate.

A hollow sphere of plastic material can also be substituted for the solid cork center core. Suitable materials for such a hollow plastic core include acrylonitrile butadiene styrene (ABS), acrylonitrile styrene, styrene, acrylate, methacrylate, methyl methacrylate, acrylic, polyvinylchloride (PVC), nylon, carbonate, polypropylene, methyl styrene, cellulose acetate, cellulose triacetate, and cellulose propionate.

Having illustrated and described the principles of my invention with reference to a preferred embodiment and several possible equivalent constructions, it should be apparent that my invention permits of modification in arrangement and detail. It is my intention not to limit my invention to the embodiments specifically disclosed but to include within its scope all obvious modifications and equivalent constructions.

I claim:

1. in a baseball or softball batting practice device including a track means, a carriage means movable freely along said track means and a spherical member simulating a baseball or softball suspended by a cord means from said carriage means,

said spherical member comprising:

a preformed spherical center core portion,

an outer bat-engaging spherical shell portion surrounding and engaging said core portion,

said spherical shell portion being formed of a resilient elastomer material,

said cord means including a cord end portion extending axially into said spherical member and axially through said shell and core portions and being wrapped in engagement with and with at least substantially one full wrap around said core portion and being embedded in an inner peripheral portion of said outer shell portion.

2. Apparatus according to claim 1 wherein said outer shell portion comprises a resilient molded urethane material cast in liquid form about said core portion and about an end portion of said core means connected to said core portion.

3. Apparatus according to claim 1 wherein said outer shell portion is formed of a rubber or rubberlike material selected from the group: polyisoprene, an interpolymer of styrene butadiene, an interpolymer of isobutyiene isoprene, polybutadiene, an interpolymer of ethylene propylene, chloroprene, an interpolymer of acrylonitrile butadiene, polyethylene,

po laypropylene, ethyl vinyl acetate and urethane.

. Apparatus according to claim 1 wherein said outer shell portion is molded of a cured cast liquid material consisting of 15 parts urethane to 1 part catalyst enabling said material to cure at room temperature.

5. Apparatus according to claim 1 wherein said spherical center core is formed of a material selected from the group: cork, an interpolymer of acrylonitrile butadiene styrene, an interpolymer of acrylonitrile styrene, polystyrene, methyl methacrylate, acrylic, polyvinylchloride, nylon, carbonate, polypropylene, methyl styrene, cellulose acetate, cellulose triacetate, and cellulose propionate.

6. Apparatus according to claim 1 wherein said center core comprises a solid cork material.

7. Apparatus according to claim 1 wherein said center core comprises a hollow sphere formed of a plastic material.

8. Apparatus according to claim 1 wherein said center core comprises a cork material and said outer shell portion comprises a urethane material, said core and body portion together having a total weight and size approximating the weight and size of a conventional softball or baseball.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,652,088 g Dated March 225 1972 Inventor(s) LOYAL SH It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the references cited:

"Quinn" should be -Quin-.

"3,554,275" should be "3,454,275".

Column 4, line 24 claim 2 "core means" should be ---cord meansw.

Column 4, line 45 claim 8 body portions" should be shell portion-a Signed and sealed this 8th day of August; 1??2.

( SEAL) Attez: is:

,EJDWARD I EIFLYEF FC 7:313:13 ROBERT GUTTSGHALK 21 meeting; Office-r Commissioner of Patents FORM PC4050 (10-69) USCOMIWDC 5o376 p69 n u 5 GOVERNMENT PRINTING ornc: was o-ass-aaa

Claims

1. In a baseball or softball batting practice device including a track means, a carriage means movable freely along said track means and a spherical member simulating a baseball or softball suspended by a cord means from said carriage means, said spherical member comprising: a preformed spherical center core portion, an outer bat-engaging spherical shell portion surrounding and engaging said core portion, said spherical shell portion being formed of a resilient elastomer material, said cord means including a cord end portion extending axially into said spherical member and axially through said shell and core portions and being wrapped in engagement with and with at least substantially one full wrap around said core portion and being embedded in an inner peripheral portion of said outer shell portion.

3. Apparatus according to claim 1 wherein said outer shell portion is formed of a rubber or rubberlike material selected from the group: polyisoprene, an interpolymer of styrene butadiene, an interpolymer of isobutylene isoprene, polybutadiene, an interpolymer of ethylene propylene, chloroprene, an interpolymer of acrylonitrile butadiene, polyethylene, polypropylene, ethyl vinyl acetate and urethane.

4. Apparatus according to claim 1 wherein said outer shell portion is molded of a cured cast liquid material consisting of 15 parts urethane to 1 part catalyst enabling said material to cure at room temperature.