DE1926389A1 - Machine for stringing tennis rackets - Google Patents

Description

Patent application Court and Slope, Inc., 6O6 Devon Avenue, Park Ridge, 111. USA Machine for stringing Tennis rackets

The invention relates to a machine for stringing tennis rackets with a racket holder for holding a tennis racket in a predetermined plane, a tension holding device with a clamping device carrier, the opposite the racket holder is movable in directions parallel to said plane, and a clamping device associated with the said carrier is movable in said directions and its clamping jaws continue to move towards or from the plane movable away to grasp a tensioned string, means for closing the jaws for gripping a string and locking means for locking the carrier.

Although machines of this type have long been known, these are far from being entirely satisfactory work. A tennis racket could be fully hand-strung by a skilled worker more quickly than with Using a machine and also with more uniform tension on the strings. Although the most advanced machines Have clamping devices for holding the string after each pull, there the clamping devices are difficult to operate and its holder can only withstand a pull in one direction.

909849/0045

stand. A tennis racket had to be re-clamped for the other direction.

The invention is based on the object of avoiding the disadvantages of previously known machines.

According to a basic feature of the invention, locking means are for locking against forces set up in all directions parallel to said plane while holding the fingered string.

According to the present invention, various features contribute to uniform tension and faster Work at. The holding clamp device is automatically lowered below the covering level when it is released, and is then freely movable into the correct position for your next operation, with an actuation of a Clamping lever or handle both the. Clamping device lifts into its working position and locked it with a turntable so that ax withstands any direction of pull. The combination of a laterally displaceable pull-and-clamp device and an automatic locking of a rotary yoke on which the tennis racket is clamped, allows the string to be pulled at the most favorable angle so that the Friction has the least possible disruptive influence on the equality of successive clamping processes. The pulling takes place with hydraulic power through precisely set and readable pressure on a manometer. The cylinder also controls a locking brake so that the turntable is locked at the start of the clamping process. The brake or The locking force is automatically increased by the reaction of the train.

909849/0046

An exemplary embodiment of the invention is shown in the figures iSarcastellt and described below

Fig. I is a perspective view of the machine, at the one cover is removed and the one with the covering a tennis racket is shown.

Fig. 2 is a top plan view of the machine of Fig. 1; at the cover and the racket jaws are away.

Fig. 2A is a similar view on an enlarged scale, with some / parts removed or shown in section while cylinder 18 is retracted.

Fig. 3 is a fragmentary sectional view essentially

borrowed on line 3.3 of Fig. 2A '

Figures 4 and 5 show a side view and top view, respectively, of the Racket holder and the lockable attachment for the retaining clamp, where some parts are used Sectional view broken away.

I? Ig. 6,7 and 8 are joi views from two sides and top of the Ealteklessne, supporting parts being shown in FIG.

Fig. S is a schematic, which essentially the hydraulics, but / shows some electrical controls / with

general description

As shown in Fig. 1, includes the one selected for illustration Machine a base 11, one of the base 11 rotatable

- Worn and essentially formed from a yoke 13,., · Turntable 12, on the upper side of which the tennis racket 14 to be strung is clamped. The one to be drawn for the purpose of bracing Page is placed in terminal 16, which by pressing your: Handle 82 is closed by hand. Then a button 17 pressed, whereupon the cylinder 18 to the rear of the piston therein-pressure medium is fed to the pull rod 19 to the outside - .. pushes to the operator. Since this pull rod carries the clamp 16, the string is pulled, one from the check valve control button 22 set exact tensile stress, set on it

fc is practiced on the pressure gauge 21 on the front control panel 2o " can be read. While the string is held under this tension, the holding clamp released from its first cold function is released 23 moved to a position under the string being drawn just inside the frame close to the tension clamp 16. When closing the handle of the clamp 23 this is in a. The raised position in which the string is gripped closes then around the string and at the same time locks the clamp base 68 on the turntable 12. The clamp 16 is now manually opened, and by means of the button 17, the pressure medium is fed to the other end of the cylinder 18, so that the pull rod 19 returned and the brake previously holding the turntable 12 is released. The turntable 12 is now by hand to approximately

'13o pivoted with the clamp · 23 moving with it to. to keep the tension of the string. The free end of the string is now threaded through the next opening and between the jaws from terminal 16, whereupon the work cycle described above. starts all over again.

Turntable structure

The attachment of the turntable is best seen in FIG. Üra the upper stub end of a fixed shaft 27 is a Coil 26 rotatably mounted. A horizontal channel-shaped rod 23

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is attached to the coil 26 and carries the yokes 13, the upper ends of which have the fixed 3-prongs for supporting and clamping the stringed tennis racket. From each jaw 29 runs a threaded pin 31 upwards, and a movable jaw that is moved by a nut 33, which can be a plug screw completes the clamp in any case. The yokes 13 are on the channel-shaped rod 20 for adaptation to various Tennis rackets adjustable and screws 34 hold them in the set positions. Through the channel-shaped rod 23 runs a threaded pin 36 and is welded to her, its Head 37 is guided into the sink 26, and thereby the pen and centering the channel-shaped rod 23 and perhaps arranging the threaded pin 36 more rigidly. By screwing it is channel-shaped Rod attached to spool 26.

A deeply slotted coil 38 is screwed onto the pin 36 and held in position with a lock nut 39. By loosening the lock nut, the coil 33 can be adjusted perpendicular to the ground Adjustment of the height of the retaining clip 23 carried by it.

The entire turntable 12 can therefore move freely on the shaft 27 turn, except when locked by the brake rod 4.1.

Combined braking and pulling

The pulling of the string and braking of the turntable are performed by the pressure cylinder 13. : jie best in Fig. 2 too As can be seen, the cylinder 13 (with its hexagonal heads 14 and 44) is channel-shaped between the upright flanges 46 of the two Angle 47 housed. The heads 43 and 44 are ■ not attached to the channel-shaped angles, and therefore the cylinder 13 can move freely in the longitudinal direction and can move perpendicular to the position determined by its working connections adjust, ; ■ ·

«09849/00 *«

If pressure medium is supplied to the rear head 44, it tries to push the piston 43 and the piston rod 49 outward. The pressure medium pressure is also applied to the rear head 44 and tries to push this and the cylinder 10 backwards. The rear head 44 is designed as a pin 51 which is firmly attached to the brake rod 41, for example by screwing it in. The brake rod 41 is also urged rearwardly by sliding actuating rods 52 loosely fitted therein and biased by springs 53. "If the supply of pressure medium to the cylinder 13 'is permitted, the Peclers 53 press the sliding actuating rods 52, which in turn press the brake rod 41 into engagement with the coil 26. The breech rod has sloping end faces 56 and - as shown in FIG. 3 - the coil 26 has correspondingly beveled end faces 57 / "which form the sides of a circumferential groove in it. Therefore, the Brensstange 41 engages the coil nit a curative effect, by which it is firmly locked, us a suitable ZLbschrägung of 3 °. / ~ on ..

A sustained flow of pressure medium to the head 44 moves the pull rod 19 outwards or forwards, which also causes the pull clamp IS is moved to pull the string to which the Sugklemme is clamped by hand. / While the string resists the pull, the pressure medium pressure builds up in the cylinder 13 to the maximum Uert for which the tension regulator 22 has been set, and the same maximum pressure medium presses cylinder 1 * 3 to the rear to increase the pressure of the brake rod 41 on the Coil to ensure that the tension does not cause the turntable to twist.

Before the string is clamped i-Jird in the tension clamp 16, can the tension clamp is pushed to a desired position on the rod 19 and the turntable is rotated by hand at the same time,

909849/0048

in order to achieve a pull at the best possible angle with respect to the frame of the tennis racket and thus to reduce as much as possible reductions in the tension of the strings due to various friction conditions.

It is important that the suc-rod 19 be guided in such a way that friction is reduced to a ϊ-iinäestaäß resulting from the fact that the tension of the string tends to impede the bankrupt structure. Any reliable form of device can be used with parallel motion "may be used, and here is shown the shape which has been found to be satisfactory under the manifold and compound boom forces present. Feed rods 61 are fixedly secured (e.g. Each of the pulling guide rods 61 slides in a bearing cylinder 63 which runs through flanges 46 and is fastened therein with snap rings 64. The bearing cylinder 63 is provided at each end with bearing sleeves 66 with which the guide rod 61 is smoothly guided Friction must be fairly even in all positions of the tension clamp 16. This is very difficult, but can be achieved by using "a line aren THiOHBSOS ball bearing idler bushing for each of the bearing sleeves 66 can be achieved.

When the pressure means is under pressure through the front head 43 of the Cylinder 13 is promoted, the piston rod 49 and the Cross head 62 is moved inward (rearward) until the cross head 62 strikes the guide cylinder 63. At this point it builds up the pressure in cylinder 18 to the maximum Uert (the higher than that allowed by controller 22). This pressure medium pressure pushes the cylinder 18 outward in the direction in which the brake rod 41 is pulled away from the spool 26, and the available pressure medium should be so high / around this achieve, the force of the springs 53 is overcome. Of the

90 9 849/004 4 bath original

Turntable can therefore be rotated freely again and is operated by Hand turned approximately 130 ° in preparation for the pull of the next string in the opposite direction.

Combined effect of the IZ old clamps

! One string held under tension by the tension clamp 16 during the year is, the retaining clamp 23 is by hand from the point on the previous string action to which it was attached, pivoted by 130 ° and attached to a new string action applied to keep it taut while the ZugHemme loosened and the turntable is swiveled by 130 ° in preparation for pulling the next string. When swiveling the Turntable ura 13o, the retaining clamp on the turntable must be locked be.

As shown in FIG. 6, the retaining clip 23 is a self-locking articulated clip carried by a movable but lockable base 63. This base 63 is provided with an upright connecting piece 69. A terminal punch 71 is provided with a shaft sleeve 62 fitted tightly into the connecting piece 69 and is rotatable and vertically movable therein. The upward movement is limited by a snap ring 73 which is seated in a hat in the shaft 72. The upper end of the clamp body 71 is equipped with a fixed jaw (74). A movable jaw 76 cooperating with jaw 74 is hinged to body 71 by a pin 77 which is held in position by a snap ring 78. A compression spring 79 arranged in a suitable connecting piece can be provided in order to press the jaws into the open position. The jaws are preferably provided with friction face plates 31.

A clamp handle 82 is by means of an actuation pin 83 and a knee joint 04 floating associated with the body 71.

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$ 800649/004

The actuating pin 33 presses the movable jaw 76 afterwards at the top when the handle 02 is operated towards the body 71 or inward. Uenn the pin 33 for the sake of convenience the rib carrying it protrudes 3S, it can be in a for move it freely in the recess provided in the body 71.

The knee joint 84 is articulated on the lower part of the rib 35 on the handle 32 and on the upper end of the push rod 37. The push rod 37 pushes a set screw 80 through which it interacts adjustable with the locking lever 39.

When the handle 82 is pivoted downward, it connects with the knee joint 34 to a double knee joint linkage, which lifts the clamp body 71 during alignment and thereby lifts jaws 74 and 76 into position on opposite sides of the string being clamped. In so far as When clamp body 71 and handle 32 are gripped together with one hand, this quickly becomes an automated assembly process. By sustained downward and inward movement of the handle 3, the knee joint linkage is further aligned, but since the Upward movement of the body 71 now through the snap ring 73 is limited, the knee linkage exerts an upward pressure on the movable jaw 76 and a downward pressure on the Lock lever 89 off. The upward pressure causes the String that is under tension due to the tension applied to it, firmly clamped. The locking lever 39 locked the retaining clip 23 fixed against relative movement between it and the turntable. So call the turntable rotate freely can, then he move .the clamped tennis racket and the clamp 23 holding the tensioned string together as Unit.

/ "from the tension clamp 16 ...

¹⁰ "'■ 909849 / 004S'". "/

BATH ORIGINAL

As shown in Fig. 4, the Kleiiutuiebel 3 9 through the Pin 91 is hinged to the slidable l'Clernnensockel 68, the both are forked for arrangement in a deep groove of the coil 33 but for movement in this over a substantial one Route. This distance is through the depth of the slot 92 in one direction and through the pin 91 in the opposite direction Direction limited to the hatred of movement in which one Locking takes place. Uenn the locking device 39 through the thrust pin 07 is pressed down, Verriecrelungsansätze 93 pressed onto the lower flange of the Sr-ule 33, P with an essentially equal pressure through the displaceable Base 63 is exerted against the upper flange. The holding clamp arrangement is thus firmly locked to the coil 30, which in turn is firmly locked to the wire table arrangement. At the same time, the set screw C! G sets the pressure of the jaws 74, 75 on the string and the locking pressure on the lugs 93 a.

Zuc; klemne

The pull clamp 16 can be essentially like the retaining clamp. 23 be formed. However, the screw 83A is in the bottom of the shaft sleeve 72A k of the body 7IA g ^e unscrewed, not ai · ³ in the nozzle S9A rotate freely, but in and can move up and down ,, The stub 69A is part of a Glaittrelgers 94 on the Pull rod 19 can slide. ^{As shown} in FIG. 3, the slide carrier 94 is normally in the vertical position, resting on the transverse head 52. LJr can, however, be swiveled down into the position shown by the broken line so that the racket handle can be swiveled past the 'Klemr.ie 15' _ffl

Hydraulic and electrical circuit

The hydraulic and electrical circuit are sufficient in Figure 9 _e

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SO9049 / Ö04I BAD ORIGINAL

-I-

c-ezeirt. The parts not yet described contain an in the figure correspondingly labeled pump and container and a pressure relief valve 96, which the pump conveyed maximum pressure determined. The pump is preferably a positive displacement pump. Cie is driven by an electric motor, not shown, which is controlled by a main switch. A Needle valve 97 regulates the speed of the pressure medium flow and thus the working speed of the parts. A hydraulic valve with two positions and four passage openings 93 is controlled by a solenoid 99 which in turn is actuated by button 17. The valve 90 is for example by a The spring is preloaded into the position in which the pressure medium source with the head 43 and the head 44 connected directly to the container are. Then the circuit operated by button 17 is closed is, the solenoid 99 controls the valve 93 in its other position, in which the pressure medium source with the head 44 and the head 43 are connected directly to the container. The adjustable pressure relief valve 22 limits the flow through the head 44 pressure exerted on the set TTert, whereby the pressure is indicated on the Drudunesser /. The button 17 / The switch shown is preferably closed and opened by successively pressing the button, it can however, if necessary, it can also be operated with the Pu3 so that both hands are free.

3s a second DrucJanesser lol is preferably provided, so that the operator can be certain that the pump is working efficiently and that there is sufficient pressure to overcome the Springs 53 provides, as well as a safe excess pressure to be supplied via the setting of the suction pressure regulator 22. : 7enn the pressure relief valve 96 is adjustable, the pressure gauge lol can also be used as a guide when making adjustments.

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Working method e -. '■

The way of working can be seen for the most part from the description under the heading "General Description".

"Tor is familiar with the stringing of tennis rackets gissen, da.3 after the snap frame was clamped on the turntable the first step in the stringing process is to anchor the part of the string from which the string is to be pulled when tensioned. Usually this is a medium one Point of a string that anchors to a central point of the frame will. For this 3: any suitable starting pin or one Start terminal are used, and, this has; .no connection with the machine. At the moment, nan prefers a small one with one Screw operated clamp, but not shown In view of the fact that the invention of the details this Klexuae is independent. vJenn the tensioning of a Sait-3 from the beginning skler.irae in one direction through consecutive Pull the tension clamp 16, the string being held by the retaining clamp 23 between successive pulling operations is finished, and when the string is attached at this end, the stringing runs from the retaining clip to the other end of the string, "venii the first gear in this direction is drawn from the tension clamp 16 to the desired tension, the Änfangsklemme is removed and the Holding clamp 23 applied to hold the tension until the next gear is pulled by the tension clamp to the desired tension has been.

' Result achieved

From the foregoing, it can be seen that all of the string pulling is by force, and not by operator-supplied work, directly or indirectly. Great uniformity can be achieved when clamping, partly because the clamping

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force is determined by the precisely set pressure medium pressure, and partly because the tennis racket is rotated and held at such an angle with each pull, and the clamp is in the side can be moved to a suitable position so that the pull is in the least frictionally affected direction. The automatic locking of the turntable when pulling prevents wasting time at this point. It is important, that not even seconds are wasted in an operation that is repeated many times in stringing a tennis racket must be grounded repeatedly. Moving the holding clamp between successive aisles is also minimal Working time in that the opening process of the clamp releases it at the same time and lowers it for the purpose of free movement, and closing the lilemmenhebels the jaws in the plane of the Lifts the strings, closes them around the string held by the tension clamp and the clamp against relative movement with respect to the The turntable is locked, again without losing precious seconds.

This results in a beneficial effect that the quality of the stringing process with a little practice it is comparable to, or better than, in the stringing of tennis rackets specialized workers who clamp by hand, and is considerably better than that achieved with the help of previously known machines Quality. An operator quickly develops a speed that is comparable to that of a specialized string tensioner, which clamps by hand, and is again significantly faster than the speed achieved with previously known machines.

By locking the turntable and the ability to move the tension clamp for a selected tension line, works the machine is also satisfactory for certain tennis rackets for which previously known machines could not be used,

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For example when the wrong Sugwinkel a string from a notch or recess in which they should be harausbewegen, - would ■. This also contributes to the fact that the tennis racket can be completely strung (both with ouersaitan and main strings-) without being removed from the turntable.

BATH ORIGINAL

9 098 49/00 UB

Claims (1)

Claims Machine for stringing tennis rackets with a Racket holder for holding a tennis racket in a predetermined plane,! Its tension holding device with a clamping device strJägeix, the opposite the racket holder is movable in directions parallel to said plane, and a clamping device, which is movable with said carrier in said directions and whose jaws continue to be on the Level to or away from this can be moved in order to grip a tensioned string, means for closing the Clamping jaws for gripping a string and locking means for locking the carrier, characterized in, that the locking means for locking against Forces established in all directions parallel to said plane when holding the gripped string are. 2.) Machine according to claim 1, characterized in that that the clamping device is movably attached to the clamping device carrier perpendicular to said plane is so that they use their jaws for gripping a tensioned string towards and away from the plane moved, and is rotatably mounted to allow an adjustment to the string direction in each position. 9098A9 / 004S kk 3) Machine according to claim 1 or 2, characterized in that that the tension holding device includes a central structure which is rigid with the racket holder is connected, and that means for such locking of the beam to the central structure are intended to hold forces in any direction parallel to said plane withstand the strings being picked. ■.; '3v ~ i,'cA-; ■■ '- - ijj.K €? /. ^: - ■. ■ k ·) Machine according to one of claims 1 to j "J, characterized in that that the means for closing the jaws also actuate the locking means for the carrier. 5) Machine according to claim 4, characterized in that that the means for closing the jaws also generate a movement through which the jaws be moved into said plane before closing it. " 6.) Machine according to claim 5> characterized in that that the means for closing the clamping jaws said movement by reacting to the clamping jaws 90.9349 / 0QAS cause closing force and that the jaws with are biased towards the open position with sufficient strength that they withstand the closing force until the stroke movement has reached its end division. 7 ·) Machine according to one of the preceding claims, characterized, that the racket holder sits on a turntable and the means for locking said carrier lock this with the turntable. 8.) Machine according to claim 7, characterized by a Ztigklemmvorrichtung whose jaws are -in the plane of the tennis racket and is movable to tighten a string in one direction, and a hydraulic cylinder-piston combination for moving the train-clamping device in the pulling direction . · -,. ': ■ ■ .. ■ -.:..- 9.) Machine according to claim 8, characterized in that that the train clamping device is previously mounted displaceably transversely to the pulling direction. 10.) Machine according to claim 9, characterized in that that the turntable can be locked against rotation '■■■ -. ■■■ ·. ORIGINALiNSPECTED 909849 / ΟΟΛβ 192Ö38 11.) Machine according to claim ΙΌ, characterized in that that the locking DES turntable against ⁵ We.f- ^r rotation by the cylinder pistons combination is effected ^ /. - ''"■-'- · - -— - '^; - - - - · - ^l ii ~ s' ■■■ 12.) Machine according to one of the claims -8- 'to lly characterized in that "^; - - ■""·""-' ■ '''-'" ■ ' ■ - "" - - that the cylinder for pulling a string up to a predetermined tension by a hydraulic Pump system is acted upon, which is an adjustable device for regulating the on, the cylinder given hydraulic pressure. 13.) Machine according to one of claims 7 to 12, characterized marked, that the turntable has a bobbin, the axis of which is near the center of the tennis racket lies, which is firmly connected to the turntable and has a deep annular groove that the Clamping device carriers and the locking means both are fork-shaped and grip around the axis and clamp the clamp carrier takes place by spreading under force against the walls forming the groove. Machine according to Claim 13, characterized in that the means for closing the clamping jaws are arranged in this way are that they cause the spreading by the reaction of the closing force. - 5 -. ORIGINAL INSPECTED 909849 / $ 004 Kl 15 ·) Machine according to claim ik, characterized in that that the Klemmvorrxchtungstrager and the locking means are fork-shaped levers which grip around the axis and pivotable on the spool
are provided in such a way that they lock the Klemmvorrxchtungstrager by pivoting by
they interlockingly engage in the groove, and that the clamping device has a toggle lever arrangement which pushes in one direction when stretching and
so a pivoting of the lever in the opposite direction to close the clamping device acts be. ■ -ι ■ »* - * ■ Blank page