US3645370A

US3645370A - Apparatus for raising and lowering a tennis court net

Info

Publication number: US3645370A
Application number: US882607A
Authority: US
Inventors: John Rodwell; Harry Marsden
Original assignee: TENNIS UNLIMITED Inc
Current assignee: TENNIS UNLIMITED Inc
Priority date: 1968-12-09
Filing date: 1969-12-05
Publication date: 1972-02-29
Anticipated expiration: 1989-02-28
Also published as: JPS4840026B1; CH516095A; DE1960803A1; BE742869A; DE6947390U; ES374702A1; IE33669L; FR2025722A1; IE33669B1; NL6918473A

Abstract

Apparatus for raising and lowering the net of a tennis court which is incorporated in the post supporting the net. The apparatus includes a hydraulically operable ram and cylinder device, the ram of which is connected to the cord of the net so that the net is raised when the ram is extended. The ram is extended by a manually operable pump. A valve biassed to the open position is located so that fluid pumped from a reservoir into the cylinder is returned to the reservoir through the valve. The valve is closed to trap fluid in the cylinder to enable the ram to be extended by insertion of appropriate coin in a coinoperable mechanism. Operation of the coin-operable mechanism starts a timing device which is operative to open the valve at a predetermined time, usually one hour, after the valve has been closed. When the valve is opened the ram retracts under the weight of the net and/or the effect of a spring to cause the net to be lowered.

Description

United States Patent Rodwell et al. Feb. 29, 1972 [54] APPARATUS FOR RAISING AND FOREIGN PATENTS OR APPLICATIONS LOWERING A TENNIS COURT NET 213,749 '4/1924 Great Britain ..273/29 R [72] Inventors: John Rodwell, Homchurch; Harry Marsden, n nf d both f England Primary Examiner-Stanley H. Tollberg Attorney-Ostrolenk, Faber, Gerb & Sofi'en [73] Asslgneez Tennis Unlimited Incorporated, New

York, 57] ABSTRACT [22] Filed: 9 Apparatus for raising and lowering the net of a tennis court [21] Appl. No.: 882,607 which is incorporated in the post supporting the net. The apparatus includes a hydraulically operable ram and cylinder o 0 device, the ram of which is connected to the cord of the net so Ffllelgll Appllmlion Priority Dita that the net is raised when the ram is extended. The ram is ex- Dec 9 1968 Great Britain 58 340/68 tended by a manually operable pump. A valve biassed to the open position is located so that fluid pumped from a reservoir Mar. 26, 1969 Great Britain ..l5,778/69 into the cynnder is rammed to the reservoir through the valve- [52] U S CL 194/91. 273/29 BB The valve is closed to trap fluid in the cylinder to enable the [51] 5/10 ram to be extended by insertion of appropriate coin in a coin- [58] Fie'ld search' 273/29, 194/9 30 50 9 T operable mechanism. Operation of the coin-operable mechanism starts a timing device which is operative to open the valve at a predetermined time, usually one hour, after the [56] Reterences cued valve has been closed. When the valve is opened the ram UNITED STATES pATENTS retracts under the weight of the net and/or the effect of a spring to cause the net to be lowered. 1,998,454 4/1935 Gordon ..273/29.4 BB

Blanchet..

16 Claims, 4 Drawing Figures PATENTEBFEB 29 1972 SHEET 1 BF 3 ATTORNEY) PAIENTEDFEBZQ I972 SHEET 2 OF 3 APPARATUS FOR RAISING AND LOWERING A TENNIS COURT NET This invention relates to apparatus for raising and lowering a tennis court net and particularly to apparatus having control means including a coin operated mechanism.

Such control means may be used with fluid pressure ram devices associated with equipment available for use by the public on payment of a fee, the operation of the ram device placing a component of the equipment in a position enabling the equipment to be used. For example, in a tennis court, the ram may operate to move the tennis court net to a playing position.

According to the present invention there is provided apparatus for raising and lowering a tennis court net, the apparatus including a coin-operable mechanism operable to place the apparatus in a condition in which the net can be raised, and a timing device operative to cause the net to be lowered at a predetermined time after the apparatus has been placed in said condition.

According to a preferred embodiment of the present invention the apparatus comprises control means for a fluid pressure ram device including a pump which, in operation, draws fluid from a reservoir and delivers it to a ram cylinder to move the ram in a predetermined direction, the ram cylinder being connected to the reservoir through valve means so that, only when the valve means is closed can the ram be moved in said predetermined direction, the control means including a coinoperated mechanism, operation of which closes the valve, and a timing device operative to cause the valve to be opened at a predetermined time after it has been closed.

The movement of the ram in said predetermined direction may be movement in a direction to extend the ram.

The timing device may include a disc rotatable by a motor at a predetermined rate, the disc having means thereon engageable by a pivotable lever to constrain the disc from movement, insertion of a coin enabling the lever to be moved to a second position to permit the disc to be rotated, the lever reengaging the said means after a predetermined degree of rotation of the disc, the lever being pivotally connected to said valve means so as to maintain the valve closed when the lever is in said second position.

The means may comprise at least one notch formed in the periphery of the disc, the notch being engageable by the lever so that the lever when in the second position is in contact with the peripheral surface of the disc. The disc or each notch may have associated therewith an associated element of magnetic material, a magnet being positioned so that when the notch is engaged by the lever the associated element lies within the magnetic field of the magnet, the arrangement being such that when the lever is moved out of the notch by the operation of the coin-operated mechanism, the effect of the magnet causes the disc to rotate so that the lever then abuts the peripheral surface of the disc adjacent to the notch thereby to maintain the lever in the second position.

The motor may comprise a spring motor controlled by an escapement mechanism or alternatively may comprise an electric motor in which case insertion of a coin in the coinoperated mechanism may actuate a switch to supply electric current to drive the timing device, the timing device, when so driven, causing a current to be applied to means for closing the valve. The means for closing the valve may be a solenoid, cnergization of which causes closure of the valve against a resilient bias.

A further valve may be provided, the further valve being normally biased to the closed position and being openable manually to allow fluid to flow from the ram cylinder to the reservoir.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:

F IG. 1 shows a tennis post containing the control means and adapted to raise and lower the net of a tennis court,

FIG. 2 shows a part sectional view of part of the control mechanism,

FIG. 3 shows a reverse view of FIG. 2, and

FIG. 4 shows a part sectional view of part of the control system illustrated in FIGS. 2 and 3.

The post 1 is intended to be used in public parks and the like having tennis courts open to the public on payment of a fee, usually for a predetermined period. It is not always practical to have an attendant present and the post about to be described enables a revenue to be obtained in the absence of an attendant. Thus, an income may be obtained from such facilities as tennis courts without the expenses of an attendants wages and other overheads.

The tennis post 1 has a tubular upstanding member 1 within which is located a hydraulic ram and cylinder device 2 controlled by a coin-operated control unit shown generally at 3. The ram has a main housing containing a chamber 4 and a ram element 5 extendable with respect to the character 4. The ram element 5 is connected to a piston (not shown) slidable in the chamber 4 in the housing in a conventional manner. A fluid reservoir 6 is also contained in the housing and a manually operable pump 7 is provided to enable fluid to be pumped under pressure from the reservoir 6 to the chamber 5 in the housing to thereby move the piston and extend the ram element 5. Fluid is returned from the chamber 4 to the reservoir 6 through a return system comprising a pipe 8, a hydraulic junction box 9, a main control valve 10 and a further pipe 11. The control valve 10 controls the flow of fluid through the return system, the control valve 10 being normally biased to the open position so that fluid pumped into the chamber 4 is free to return to the reservoir 6 through the return system. If the valve is urged to the closed position, the fluid pumped into the chamber 4 is trapped therein and the ram 5 is thereby extended.

The housing containing the chamber 4 of the ram and cylinder device 2 is secured to the upper portion of the post and the extensible ram 5 is arranged to extend downwardly within the post. A tennis court net supporting cord 12 is secured to the ram 5 and passes upwardly over a pulley 13 located adjacent to the top of the post and then horizontally across the tennis court to a conventional post on the far side thereof. Thus when the ram 5 is extended the cord 12 is pulled downwardly by the ram 5 and the net is raised to the correct position. The ram 5 is extended manually by the manually operable pump 7 when the control valve 10 is closed by operation of the coin-operated mechanism, the valve being maintained in the closed position by a timing device 14, shown in greater detail in FIGS. 2 and 3, for a predetermined period, usually 1 hour.

The coin-operated control unit 3 has a selector arrangement of known type (shown in outline in FIG. 2 reference 15) to ensure the use of the correct coin. The selector arrangement 15 is mounted on a housing 16 of the control unit 3. A lever 17 is pivotally mounted on the housing 16 so as to pivot about an axis 18, the lever 17 carrying a cam follower 19 in the form of a small roller rotatably mounted on the lever 17. The cam follower 19 is arranged to cooperate with notches formed in the periphery of a timing disc 27. An edge face 20 of the pivotable lever 17 is arranged to cooperate with an edge face 21 on a control lever 22 mounted on the housing 16 so as to pivot about an axis 23. The edge faces 20 and 21 are positioned adjacent a coin outlet 36 of the selector arrangement 15 so that an appropriate coin, on leaving the selector, lodges between the edge faces, 20, 21, of the levers l7 and 22. The control lever 22 is biassed by a coil spring 24 away from the edge face 20 of the lever 17, a control knob 25 being provided by which the control lever 22 may be pivoted inwardly against the resilient bias. The pivotable lever 17 .is biassed by a coil tension spring 26 so as to urge the edge face 20 towards the control lever 22 and the cam follower 19 into engagement with the periphery of the timing disc 27. The rotatable timing disc 27 is formed of a nonmagnetic material such as a synthetic plastics material and has six notches 28 disposed equidistantly around its periphery. A series of magnetic elements 29, formed of soft iron, are disposed equidistantly about the disc adjacent the periphery thereof, each of the magnetic elements 29 being associated with a respective one of the notches 28. The magnetic elements 29 are riveted to the timing disc 27. A magnet 30 is positioned adjacent to the periphery of the disc in such a position that when the cam follower 19 is located in a notch 28 the soft iron element associated with that notch lies within the magnetic field of the magnet 30 in such a way that when the cam follower 19 is withdrawn from the notch, the magnetic force causes the disc 27 to rotate to align the element and the magnet 30 so that the cam follower l9 abuts the peripheral surface of the disc 27 adjacent to the notch and thus cannot fall back into the notch. The disc 27 is mounted so as to be freely rotatable on a shaft 31. The disc 27 is rotatable by a spring motor 32 of known type which is controlled by a convention escapement mechanism so as to cause the disc to rotate at predetermined rate. The motor 32 is engageable with the disc 27 through a peg 33 which projects into an annular slot 34 formed in the disc.

The selector arrangement has an inlet 35 through which coins are inserted into the mechanism, an operative outlet 36 through which coins may pass to fall between the faces and 21 of the levers l7 and 22 respectively and a reject outlet 37 through which rejected coins are returned to the inserter. A collection box 38 is located below the operative outlet 36 to collect coins which are not rejected.

As shown in FIG. 3 the pivotable lever 17 is connected to a further pivotable member 39 pivotable about the axis 18. The member 39 has two arms, one arm 40 operating a counter 41 each time the lever 17 is pivoted to its second position where it abuts the periphery of the timing disc 27, the second arm 42 abutting a control member 43 of the main control valve 10 so that pivotable movement of the arm 42 about the axis 18 causes the control member 43 to move between an open and a closed position. The arm 42 also operates an antistacking linkage 44 which prevents more than one coin being held in the coin-operated mechanism at a time. The linkage comprises a first member 45 slidably mounted on the housing 16 so as to be slidable longitudinally into and out of engagement with one end 46 of a further member 47 pivotally mounted on the housing so as to pivot about an axis 48. A projecting arm 49 projects at right angles from the other end of the member 47 so as to engage part of the mechanism of the selector arrangement 15. Thus, when the pivotable lever 17 has been moved to its second position abutting the periphery of the timing disc 27 the arm 45 is moved to cause the pivotable member 47 to pivot clockwise as viewed in FIG. 3, so that the projecting arm 49 moves part of the selector arrangement to a position such that further coins inserted therein are automatically rejected whether they are appropriate coins or not.

The control lever 22 is coupled through a sliding connection 50 to a lever 51 mounted on the housing 16 so as to pivot about a pivotable connection 52, the lever 51 abutting a control member 53 of an adjusting valve 54, the hydraulic junction box 9 being mounted on the adjusting valve 54. The adjusting valve 54 is biassed to the closed position.

As shown in greater detail in FIG. 4, the junction box has an inlet port 56 connected to the chamber 4 of the hydraulic ram device 2 through the pipe 8 an outlet port 57 leading to the main control valve 10, an outlet 58 leading to the adjusting valve 54, and an outlet 59 leading to the reservoir 6. A pressure relief valve 60 is interposed in the path between the inlet 56 and the outlet 59. The pressure relief valve 60 comprises a ball 61 resiliently biassed into engagement with a valve seat 62 and is arranged to open when greater than a predetermined pressure prevails in the chamber 4 of the hydraulic ram device 2.

The operation of the tennis post is as follows:

If the correct coin is inserted in the selector arrangement 15, the coin falls from the coin operative outlet 36 and lodges between the

faces

20 and 21 of the

levers

17 and 22 respectively. If the control knob is then pushed in, the control lever 22 pivots against its resilient bias and this motion is transmitted through the coin to the pivotable lever 17 to thereby cause the lever to pivot about the axis 18 against its abutting the periphery of the timing disc, the arm 42 is moved resilient bias. This pivotal movement of the lever 17 causes the follower 19 to be withdrawn from the notch in which it is located. The timing disc 27 is thus free to rotate on its shaft, and due to the magnetic influence of the magnet 30 on the magnetic element associated with the notch, the disc 27 is rotated slightly to align this element with the magnet 30. Thus, when the control knob 22 is released the control lever 22 returns to its initial position under the action of its resilient bias while the pivotable lever 17 is urged by its resilient bias until the cam follower 19 contacts the peripheral surface of the timing disc 27. Since the disc 27 has been rotated slightly by the magnet the follower 19 abuts the peripheral surface adjacent to the notch in which it was located. The pivotable lever 17 is thus located in its second position and the coin is free to fall from between the control lever 22 and the pivotable lever 17 into the collection box 38.

Since the timing disc 27 is not constrained from movement by the follower engaging in the notch the spring motor 32 is then able to rotate the disc 27. Since the magnet has already rotated the disc 27 slightly, the drive peg 33 through which the disc is driven by the spring motor does not abut the end of the annular slot and, therefore, there is an initial period in which the motor 32 is rotating the peg but in which the disc does not move. However, as this is the same for every cycle it does not affect the accuracy of the time in which the disc is being rotated by the motor. When the peg 33 contacts the end of the annular slot 34 the disc 27 is rotated by the motor 32 until the follower 19, which follows the peripheral surface of the disc 27 drops into the next notch thus preventing the disc from rotating further. When the lever 17 is in its second position to a position in which it maintains the control valve 10 in the closed position. Thus fluid may be pumped from the reservoir 6 into the chamber 4 of the ram and cylinder device 2 to extend the ram 5 to thereby raise the tennis net.

The fluid pressure generated in the chamber 4 is applied to the inlet port 56 of the hydraulic junction box 9 but is prevented from passing back to the reservoir since the main control valve 10 is in the closed position, and the adjusting valve 54 is normally biased to the closed position. If greater than a predetermined pressure is generated in the chamber 4 by excessive pumping of the pumping handle 7, the ball 61 of the pressure release valve 60 is lifted from its seat by this pressure and the excess fluid is allowed to pass through the outlet port 59 back to the reservoir 6 to thus relieve the pressure.

1f the ram is extended to such an extent that the net is raised to a level higher than that required, the control lever 22 may be pressed to pivot the lever 51 to thereby open the normally closed adjusting valve 54. When the adjusting valve is open hydraulic fluid flows from the chamber 4 in the device 2 through the inlet port 56 of the junction box 9 and out of the outlet port 58 through the opened adjustment valve 54 and hence to the reservoir 6. This release of fluid allows the ram 5 .to contract slightly thus causing the net to be lowered.

At the end of the predetermined time the cam follower 19 drops in the next notch preventing the disc 27 rotating further, and this causes the pivotable lever 17 to pivot to its first position causing the control arm 42 to pivot away from the control member 43 of the main control valve 10 and the member 45 of the antistacking linkage 44 to thus enable the main control valve 10 to return to the open position and the antistacking linkage 44 to return to its initial position. Thus, the control valve 10 is opened to allow fluid to flow from the chamber to the reservoir and the hydraulic ram 5 retracts, either under the weight of the net or other resilient means, to thereby move the net to a lowered position.

in an alternative embodiment, it is envisaged that the timing device may be an electric motor and in this case, an appropriate coin inserted in the mechanism is arranged to contact a microswitch, actuation of the microswitch causing electric current to be supplied from an electrical supply to the timing device. Operation of the timing device causes an electric current to be applied to a solenoid which controls the operation of the main control valve. The control valve is normally biassed to the open position by a spring.

An override switch is provided to override the electrical current from the timing device to the solenoid controlling the control valve to enable the control valve to be opened to enable the height of the net to be adjusted as described previously.

The operation of this embodiment is as follows:

If the correct coin is inserted in the selector arrangement, the coin falls to a position in which it actuates the microswitch. When the switch is actuated electric current is supplied to the timing device. The timing device is arranged to supply electric current to a solenoid for a predetermined period, usually 1 hour. The supply of electric current to the solenoid energizes the solenoid which moves the main control valve to a position in which the control valve is closed. Thus, by operating the manually operable pump the tennis court net may be raised to its raised position.

If the pump is pumped to an extent to raise the net above the desired position the override switch may be operated to deenergize the solenoid and thus open the control valve. This causes the net to be lowered. Release of the override switch causes the solenoid to be reenergized and the control valve is closed again and the net is located in a new lower position. If the net is too low it may be raised in the usual way by operation of the manually operable pump.

At the end of the period for which the solenoid is energized by the timing device, the timing device is switched off, the solenoid is deenergized and hydraulic control valve is opened to cause the net to be lowered. The switching off of the timing device causes the microswitch to be reset so that no electric current is supplied to the timing device until a further coin is inserted in the coin-operated mechanism.

Although this invention has been described with respect to a tennis post it will be appreciated that the invention could equally well be applied to all types of net such as those used on badminton courts and also to other equipment components such as the lighting sets provided over billiard tables which are raised and lowered to an operating position. It will also be appreciated that the term coin'-operated mechanism may include the use of tokens and the like and is not to be construed as being limited to the use of coins of the Realm.

We claim:

1. Control apparatus for moving a sports barrier such as a tennis net, or the like, in different directions, which apparatus comprises valve means;

a coin-actuated mechanism operably connected to said valve means to shut said valve means;

a fluid reservoir;

a pump;

means flowably connecting said reservoir and said pump, said pump being operable for producing fluid pressure;

means flowably connecting said pump to said valve means for supplying fluid pressure thereto;

a fluid pressure ram in a ram cylinder actuated by said fluid pressure, said ram being operably connected with said barrier, said ram being movable in a predetermined direction to move said barrier in one direction;

a timing device;

means connecting said timing device to said valve means, said timing device being operable to open said valve means at a predetermined time after said valve means have been shut, said open valve means being adapted to bleed said cylinder of said fluid pressure thereby to cause said ram to move in a direction opposite to said predetermined direction, which opposite directional movement of said ram causes said barrier to move in a direction opposite said one direction.

2. Control means as claimed in claim 1, wherein said barrier includes a supporting rope element secured to said ram such that movement of said ram in said predetermined direction draws upon said rope to move said barrier in one direction and movement of said rarn in the opposite direction moves said rope to cause said barrier to move in the opposite direction.

3. Control means as claimed in claim 1 in which the movement of the ram in said predetermined direction is movement in a direction to extend the ram.

4. Control means as claimed in claim 3 in which the timing device includes a disc rotatable by a motor at a predetermined rate, the disc having means thereon engageable by a pivotable lever to constrain the disc from movement, insertion of a coin enabling the lever to be moved to a second position to permit the disc to be rotated, the lever reengaging the said means after a predetermined degree of rotation of the disc, the lever being operatively connected to said valve means so as to maintain the valve closed when the lever is in said second position.

5. Control means as claimed in claim 4 in which the means comprises at least one notch formed in the periphery of the disc, the notch being engageable by the lever so that the lever when in the second position is in contact with the peripheral surface of the disc.

6. Control means as claimed in claim 5 in which the or each notch may have associated therewith an associated element of magnetic material, a magnet having positioned so that when the notch is engaged by the lever the associated element lies within the magnetic field of the magnet, the arrangement being such that when the lever is moved out of the notch by operation of the coin-operated mechanism the effect of the magnet causes the disc to rotate so that the lever then abuts the peripheral surface of the disc adjacent to the notch thereby to maintain the lever in the second position.

7. Control means as claimed in claim 6 in which the motor comprises a spring motor controlled by an escapement mechanism.

8. Control means as claimed in claim 6 in which the motor comprises an electric motor.

9. Control means as claimed in claim 8 in which insertion of a coin in the coin-operated mechanism actuates a switch to supply electric current to drive the timing device, the timing device, when so driven, causing a current to be applied to means for closing the valve.

10. Control means as claimed in claim 9 in which the means for closing the valve is a solenoid, energization of which causes closure of the valve against a resilient bias.

11. Control means as claimed in claim 4 in which the motor is engageable with the disc through a peg which projects into an annular slot formed in the disc.

12. Control apparatus as claimed in claim 1 in which a further valve is provided, the further valve being normally biassed to the closed position and being openable manually to allow fluid to flow from the ram cylinder to the reservoir.

13. Control means as claimed in claim 1 including a pressure relief valve by which the pressure generated by said pump is limited to a predetermined value.

14. Control means as claimed in claim 1 in which the coinoperated mechanism includes means for preventing coins falling to an operative position while the said valve is closed by operation of the coin-operated mechanism.

15. Control means as claimed in claim 1 in which the ram is adapted to raise and lower the net of a tennis court.

16. Control means as claimed in claim 13 in which the control means is incorporated in a tennis post adapted to support a net of a tennis court.

Claims

1. Control apparatus for moving a sports barrier such as a tennis net, or the like, in different directions, which apparatus comprises valve means; a coin-actuated mechanism operably connected to said valve means to shut said valve means; a fluid reservoir; a pump; means flowably connecting said reservoir and said pump, said pump being operable for producing fluid pressure; means flowably connecting said pump to said valve means for supplying fluid pressure thereto; a fluid pressure ram in a ram cylinder actuated by said fluid pressure, said ram being operably connected with said barrier, said ram being movable in a predetermined direction to move said barrier in one direction; a timing device; means connecting said timing device to said valve means, said timing device being operable to open said valve means at a predetermined time after said valve means have been shut, said open valve means being adapted to bleed said cylinder of said fluid pressure thereby to cause said ram to move in a direction opposite to said predetermined direction, which opposite directional movement of said ram causes said barrier to move in a direction opposite said one direction.

2. Control means as claimed in claim 1, wherein said barrier includes a supporting rope element secured to said ram such that movement of said ram in said predetermined direction draws upon said rope to move said barrier in one direction and movement of said ram in the opposite direction moves said rope to cause said barrier to move in the opposite direction.

14. Control means as claimed in claim 1 in which the coin-operated mechanism includes means for preventing coins falling to an operative position while the said valve is closed by operation of the coin-operated mechanism.