US3466865A - Apparatus for stopping a brakeequipped spindle rotor in a predetermined position - Google Patents

Description

Sept. 16, 1969 G FRANZEN ETAL 3,465,865

APPARATUS FOR STOPPING A BRAKE-EQUIPPED SPINDLE ROTOR IN A PREDETERMINED POSITION Filed June 24. 1968 5 Shee'cs-Sheet 1 /IVVE/Y T 0173 5 Sept. 16, 1969 G, FRANZEN ET AL 3,466,865

APPARATUS FOR STOPPING A BRAKE-EQUIPPED SPINDLE ROTOR IN A PREDETERMINED POSITION Filed June 24, 1968 5 Sheets-Sheet 2 Sept. 16, 1969 G. FRANZEN ET AL 3,466,865

APPARATUS FOR STOPPING A BRAKEEQUIPPED SPINDLE ROTOR IN A PREDETERMINED POSITION Filed June 24, 1968 5 Sheets-Sheet 5 /36 l r I'l fl] Sept. 16, 1969 G. FRANZEN ETA'- 3,466,865

APPARATUS FOR STOPPING A BRAKEPEQUIPPED SPINDLE ROTOR IN A PREDETERMINED POSITION Filed June 24, 1968 5 Sheets-Sheet 4 5 Sheets-Sheet 5 Mfrs/ron. s

Sept. 16, 1969 G, FRANZEN ETAL APPARATUS FOR s'roPPING A BRAKE-EQUIPPED SPINDLE Ro'roR 1N A PREDETERMINED POSITION Filed June 24, 1968 United States Patent O 3,466,865 APPARATUS FOR STOPPING A BRAKE- EQUIPPED SPINDLE ROTOR IN A PRE- DETERMINED PGSITION Gustav Franzen, Neersen, and Ulrich Lossa and Willi Heimes, Krefeld, Germany, assignors to Palitex Project-Company G.m.b.H., Krefeld, Germany Filed June 24, 1968, Ser. No. 739,244 Claims priority, application Germany, June 23, 1967, P 42,444 Int. Cl. D01h 13/18 U.S. Cl. 57-88 12 Claims ABSTRACT F THE DISCLOSURE Stop arrangement for rotor which is rotatable on a shaft in which a brake disposed between the shaft fand rotor is actuatable to slow the rotor down to a low speed. A stop arrangement consisting of cooperating elements on the rotor and shaft is inoperative due to centrifugal force when the rotor is rotating at operating speeds but becomes effective when the rotor is slowed down and halts the rotor in a predetermined rotated position.

The present invention relates to an apparatus for stopping a 'brake-equipped spindle rotor in a predetermined position. When threading the thread into the spindle rotor, for instance, of a multiple twisting operation, or in view of a thread break, it is necessary to stop the spindle rotor, and it is also necessary that when the spindle rotor stops, the thread exit opening of the thread storage disc will point in the direction toward the side where the operator stands.

Various spindle brakes are known for braking the spindle rotor. In addition to spindle rotors equipped with braking jaws adapted from the outside to brakingly engage the whorl, there are also known spindle rotors which are equipped with two braking jaws adapted to engage the inner braking surface of the whorl and for purposes of braking to spread radially outwardly, said last mentioned Ibraking jaws being adapted when spreading to exert a braking pressure upon the inner surface of the whorl to thereby brake the spindle.

After the spindle rotor has been completely braked to a standstill, in most instances the thead exit opening of the thread storage disc does not occupy the desired rotated position necessary for threading the thread. Consequently, it is necessary to disengage the brake, to rotate the rotor by a corresponding angle so that the thread exit opening faces the operator, and then again to engage the brake. These rather time consuming and costly operations are disadvantageous. Especially with otherwise automatic machines it is the tendency to have the thread exit openings of all spindles at a standstill thereof point precisely in a predetermined direction.

The same problem is also encountered with prespinning machines. The placing of the flyer into a predetermined direction is, in connection with prespinning machines, solved in such a way that all flyers continue rotating at a low speed until by means of a setting relay the desired flyer position is determined in which all iiyers are then stopped together.

With yer spinning frames the spindle drive is alternately engaged and disengaged by means of an electric magnetic switch until the desired yer position has been obtained. With these heretofore known machines, however, always an entire group or even an entire side of spinning stations is stopped by stopping the entire drive of the liyers.

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It is an object of the present invention to provide a device for stopping each individual brake-equipped spindle rotor of a multiple twisting machine, by means of which the spindle rotors can selectively be stopped individually and independently of each other in a certain predetermined position.

It is another object of the invention to provide a device, as set forth in the preceding paragraph, in which it is not necessary manually to move the spindles into a predetermined position for purposes of threading.

These and other objects and advantages of the invention will appear more clearly from the following specilication, in connection with the accompanying drawings, in which:

FIGURE l is an isometric view of a spindle within the area of the spindle rail.

FIGURE 2 is a section through the spindle bearing of the spindle according to FIG. l, but with a stopping device modified over that of FIG. 1.

FIGURE 3 is an exploded view of the stopping device according to FIG. 2.

FIGURE 4 represents a section through the spindle bearing of the spindle according to FIG. 1, but with a still further modified stopping device.

FIGURE 5 is a perspective view of the bearing stock of the spindles according to FIGS. 1-4.

FIGURE 6 illustrates a section through the spindle bearing with still another stopping device.

FIGURE 7 is a section through the spindle bearing similar to that of FIG. 6, but with a still further modification of the stopping device.

FIGURE 8 illustrates partially in view and partially in section, the spindle bearing of FIG. 2 on a reduced cale with regard to FIG. 2, and equipped with a braking ever.

FIGURE 9 shows the spindle bearing of FIG. 8 with a modified braking lever.

FIGURE l0 is a partial view of the braking lever according to FIG. 9 with modified positive guiding means for the slide.

It has been attempted heretofore to solve the problem underlying the present invention by means of an inner jaw brake in such a way that a stationary locking mechanism is connected with the actuating lever for the inner brake of the spindle rotor while a bolt of said locking mechanism is adapted to move against the thrust of a spring into an arresting recess of the whorl. Thus solution, however, has the drawback that the locking mechanism will, during the entire braking operation, frictionally engage the rotating whorl, thereby bringing about an undue wear of the whorl and a loss in energy during the rotation of the spindle rotor.

According to a further heretofore known suggestion to solve the above outlined problem, the spindle rotor restarted after a first stoppage is held in the respective predetermined position not by means of a mechanically operable locking mechanism, but by a magnet which operates Contact free and thereby free from frictional wear.

In an effort to provide a mechanically effective device for stoppin gthe spindle rotor in a predetermined position to facilitate the threading of the thread in the spindle rotor and the thread storage disc, which device will be effective automatically in conformity with the rotation of the spindle rotor, the present invention starts with a device of the above mentioned type and is characterized in that a stationary portion of the spindle is provided with a recess adapted to be closed by a filling body while an arresting element supported by the spindle rotor and movable radially outwardly by centrifugal force will engage said recess when the spindle rotor is braked, and is adapted to be withdrawn from said recess by displacement of the lling body into said recess.

The above makes possible the following working operation: The arresting member which is freely movably held by the spindle rotor is during the rotation of the spindle rotor, due to the centrifugal force, kept away from the recess in the stationary portion of the spindle. During the braking operation the arresting member will, due to the lack of centrifugal force, move into the area of the recess and is able directly prior to the stopping of the spindle rotor to engage said recess. In this way the spindle rotor will be safely arrested in a predetermined position thereof without expensive or complicated mechanical devices with springs and locking means which at least during the braking operation continuously frictionally engage the spindle rotor. Only when again starting the rotor last arrested in a certain position, the arresting member must move out of the recess to which end, in conformity with the present invention, the iilling body may be in the form of an axially displaceable slide.

The arresting member may be arranged at various areas of the spindle rotor, and the recess may be provided at various portions of the stationary part of the spindle. Thus, in conformity with the present invention, the recess may be provided in a collar surrounding the bearing stock, and the arresting member may be held by the inner wall of the whorl.

According to a specic embodiment of the invention, the arresting member may be in the form of a lever on the inner wall of the whorl above the said collar, and may be tiltable radially outwardly.

According to another embodiment of the invention, the arresting member may be in the form of a lock or latch which at the level of the collar is radially outwardly displaceable against the thrust of a spring.

According to a further development of the invention, the arresting member may be designed as ball or roller which is guided in an inclined upwardly radially outwardly direction bore provided in the marginal area of the lower wall portion.

If desired, the arresting member may also be designed in the form of an upwardly tiltable lever.

The braking of the spindle rotor by means of an inner jaw brake is most expediently effected in a manner known per se, through the intervention of a brake level pivotally connected to a spindle bearing housing. When said brake lever is tiled, it brings about a rotation of the spreading bolt, which in its turn, spreads the break jaws. For purposes of simplifying the braking operation which with the device according to the invention must be effected parallelly with a displacement of the filling body for freeing the recess, it is possible in conformity with the Iinvention to bring about the displacement of the filling body by means of an arm of the brake lever. Simultaneously, with the tilting of the brake lever, the filling body will automatically be displaced so that when braking, the recess will be freed, and when again starting the spindle, the said recess will be closed.

It may also be advantageous together with the tilting of the brake lever, in addition to braking the spindle rotor to a standstill, also to initiate a short term starting of the spindle rotor. Most expediently, the opening of the closed brake jaws is effected for a stort time restarting of the rotor, by means of the same tilting movement of the brake lever which tilting movement previously brought about a complete braking. According to the present invention this can also be realized by arranging the brake mandrel or brake bolt in a housing which is pivotally arranged on the brake lever and having its rearward end extending through said housing, said brake mandrel being rearwardly displaceable again a spring force. This end of the brake mandrel is displaceable against a rocker which arrests the housing against tilting. In this way the braking of the spindle rotor up to the stopping thereof in a predetermined position will be assured in a reliable 4 and simple manner. Only one single displacement of the brake lever for braking, restarting, and iinal stop of the spindle rotor in the desired rotor position is necessary.

Referring now to the drawings in detail, the arrangement shown therein comprises a spindle rail 1 extending along the spinning machine and having the spindle journalled in said spindle rail by means of its spindle shank. For the sake of clarity, FIG. l shows only the essential parts of the spindle, namely, the whorl 5 driven by the tangential belt 4, the thread storage disc 6 rotating with the whorl 5, the thread passage 7 leading radially out of the thread storage disc 6, the turntable 8 and the protective pot 9 extending around the delivery bobbin (not shown). The rotating parts form the spindle rotor 3. The whorl 5 in addition to surrounding the bearing stock 2 also surrounds an arresting device generally designated 10, while the lower marginal area 11 of said whorl 5 extends around an inner jaw brake generally designated 12.

The inner jaw brake 12 comprises the two brake jaws 14 and 15 which are outwardly tiltable around the pivot 16 supported iby the spindle rail 1. To this end, the spreading mandrel 17 axially extending between the brake jaws 14 and 15 and engaging the spreading gap thereof is rotated. The brake surfaces of the brake jaws 14 and 15 will thus engage the :brake surface 18 ofthe lower marginal portion of the whorl so that the whorl 5 and consequently also the spindle rotor 3 are `braked.

Above the lower marginal area 11 of the whorl 5 or above the inner jaw brake 12, according to the embodiment of FIGS. l to 4 an arresting device 10 is provided on the inner wall of the whorl and on the bearing stock 2. By means of this arresting device the spindle rotor 3 greatly reduced in its speed is arrested in such a position that the thread guiding passage 7 has its outlet opening directed to the operator side of the machine. To this end the stationary part of the spindle, namely, the collar 21 of the bearing stock 2 is provided with a groove 20 adapted to be closed by a slide 19. An arresting member supported by the whorl 5 and movable radially outwardly by centrifugal force is adapted when the spindle rotor 3 is braked to move into the said groove 20 and to tbe withdrawn from said groove by displacing the slide 19 into groove 20 for starting the spindle rotor.

The arresting device may be designed in different ways. According to FIG. l, above the collar 21 on the bearing stock 2 having the axial groove 20 milled therein, a radially outwardly pivotable lever 23 is pivotally connected to a radially inwardly protruding ring 22 of the whorl 5.

According to FIG. 2, the arresting member is formed by a locking member 24 which at the level of the collar 21 is radially displaceable on the inner wall of the whorl. The locking memberI 24 is embraced by a ring 26 which latter is connected to the inner wall of the whorl by means of screws 25 so as to be prevented from rotation, a recess 27 being provided to this end. VIn order to limit a radially inwardly directed displacement of the locking member by means of a spring 28 which is arranged in the center in a line bore and which rests against the inner wall of the whorl, the said locking member has its upper and lower end provided with shoulders 29 and 30 which, when the locking member 24 engages the groove 20 freed by the slide 19 and pertaining to ring 21, will engage the pertaining surfaces of the recess 27 of ring 26.

The embodiment shown in FIG. 4 is similar to that of FIG. 2 but differs therefrom primarily in that the perspectively shown locking member 31 has its longitudinal sides provided with shoulders 32 and 33 and is not radially inwardly displaceable by spring force. Instead, the locking member 31 is, due to its own weight radially inwardly displaced. To this end, the ring 34 which embraces the locking member 31 has the recess 35 provided with a sliding surface at the bottom, said sliding surface being radially inwardly and downwardly inclined. The locking member 31 has its lower end provided with a correspondingly inclined profile which tapers radially inwardly. In this way the slide 31 will, due to gravity, automatically slide radially inwardly into the groove of ring 21 when the spindle rotor 3 is close to its complete standstill.

According to FIGS. 6 and 7, the arresting device is provided in the lower marginal portion 11 of the whorl which has a somewhat larger diameter, whereas the lcorresponding recess is provided in the spindle rail 1. According to the embodiment shown in FIG. 6, a roller 37 is guided in an inclined upwardly and radially outwardly directed bore 36 in the lower marginal portion 11 of the whorl. According to the embodiment of FIG. 7, the upwardly lpivotable lever 38 is pivotally connected to the lower marginal portion 11 of the whorl. The recesses 40, 41 provided in the spindle rail 1 or a plate 39 thereon and adapted to be engaged by the roller 37 or the lever 38 are adapted lby means of enlarged head portions 42a and 43a of bolts 42 and 43 to be closed, said bolts being displaceable in the spindle rail 1 in a direction parallel to the bearing stock 2.

All embodiments of the arresting device according to FIGS. 1 to 7 having in common that the arresting members 23, 24, 31, 37, and 38 will when the spindle rotor 3 is in operation move radially outwardly in view of the centrifugal force acting thereon. Consequently the arresting devices operate automatically in conformity with the movement of the spindle rotor.

The operation of the brake in cooperation with the arresting device is as follows:

If, for instance, a thread has broken during the spinning or twisting operation, it is necessary that for threading the thread into the hollow shaft of the spindle and subsequently into the thread guiding passage 7 radially leading out of the thread storage disc 6, the said thread guiding passage 7 occupies such a position that it points or ends at the operator side. To this end, for instance, the brake lever 13 of FIG. 1 the brake bolt 43 of which engages the lever 44 of the downwardly extending spreading bolt I17 is pivoted upwardly in the direction of the spindle rail 1 about a bolt 45. As a result thereof the lever 44 moves into the position indicated in dot-dash lines in FIGS. 8 and 9 and the turning of the spreading bolt 17 brings about the pivoting of the braking jaws 14 and 15 of the inner jaw brake 12 about the pivot 16 so that the whorl 5, in view of the friction between the stationary braking jaws 14 and 15 and the rotating Ibraking surface 18 of the whorl 5 will :be braked. Simultaneously therewith, for instance, a displacement of the slide 19 from groove 20 is effected whereby the corresponding arresting member 23, 24 or 31 will with the whorl 5 rotating slowly have the possibility to enter the groove 20 which is no longer closed. At this instant the arresting member stops the rotor 3 completely whereby automatically the thread guiding passage 7 of the thread storage disc 6 will have a position so as to be directed to the operators side.

If the arresting member during the last revolution of the whorl 5 should for some reason not have engaged the groove 20 pertaining thereto which, however, will happen only rather seldom, and instead engages the ring 21 from the outside, the jaw brake 12 is for a brief restarting of the whorl 5 again disengaged by means of the tangential belt 4 which still engages the whorl, whereupon the arresting member after a partial revolution of the whorl 5 will enter the groove 20 at any rate.

If the thread has been threaded and if it is now desired to again start the spindle, it is merely necessary to displace the slide 19 in upward direction (the upper end of slide 19 being somewhat pointed as shown in FIG. 5) which will result in a disengagement of the arresting member from groove 20. As a result thereof, the interlocking between the whorl 5 and the bearing stock 2 is disengaged and the spindle rotor 2 can start again inasmuch as simultaneously with the displacement of the slide 19, the brake 12 will be completely disengaged.

The turning of the spreading bolt 17 for braking and if desired for a subsequent brief restarting of the rotor 3, in combination with the corresponding displacement of the slide 19 is effected by a single pivoting of the brake lever 13 according to FIGS. 1 and 10 or of the brake lever 56 according to FIGS. 8 and 9 in the direction toward the spindle rail 1.

The brake lever according to FIGS. 1 and 8 is supported by the bearing support 46 connected to the spindle rail and is pivotable about the bolt 45 connected to the bearing support 46. The braking arm 13 is held in the pivoted position shown in FIGS. l and 8 by means of a spring 47 which is connected to the brake lever 13 and which extends behind the lever 44 of the downwardly extended spreading bolt 17. That end of the brake lever 13 which faces away from the yoke 48 is provided with an auxiliary lever 49 having an oblong hole displaceably engaged by a bolt 50 connected to the lower end of the slide 19.

When it is desired to brake the spindle rotor 3, the brake lever 13 is pivoted upwardly about the bolt 45.

In view of the pressure exerted upon the brake bolt 43, the lever 44 of the spreading bolt 17 is tilted. As a result thereof, the spreading bolt 17 turns and spreads the braking jaws 14, 15 for braking the whorl 5. Simultaneously therewith, with the upward tilting movement of the brake lever 13 the slide 19 by means of arm 49 of the brake lever is displaced out of the groove 20 in downward direction so that the locking member 24 can engage groove 20.

Inasmuch as under some circumstances the locking member 24 might not have been able to engage the groove 20, but instead rests against the ring 21 under spring pressure, a restarting of the whorl 5 is necessary. To this end, the brake bolt 43 is arranged in a housing 51 which is embraced by the brake lever 13 in a longitudinal groove 13a thereof while said housing is likewise pivotable about the bolt 45. The brake bolt 43 by means of its rear end 52 extends through the housing 51 and is rearwardly displaceable in said housing S1 against the pressure of spring 53. The rear end 52 of the brake bolt 43 engages a pivotable lever 54 having one end thereof pivotally journalled in the brake lever 13 by means of a pivot 13b whereas the other end of said lever 54 arrests the housing 51 against a downward pivot movement about the bolt 45.

When the brake lever 13 after the braking of whorl 5 is tilted further upwardly, due to the upward tilting movement of the brake lever 13, the thrust of spring 53 will be exceeded which spring keeps brake bolt 43 in housing 51 against an axial displacement, the rearward end 52 of the brake bolt 43 is displaced against the lever 54 whereby the latter disengages the interlock between the housing 51 and the brake lever 13. Housing 51 pivots about the bolt 45 and thus releases the lever 44 and thereby also the inner jaw brake 12 so that rotor 3 can again rotate slowly. After a partial revolution of rotor 3, the engagement of locking member 24 in groove 20 of ring 21 will be safely effected.

FIG. 9 illustrates a brake lever similar to that of FIG. 8, but differing therefrom in that the brake lever is mounted on the spindle rail 1 for downward pivoting about bolt 55 for carrying out a braking operation. According to the embodiment, the automatic displacement of the slide 19 during the braking operation is effected by cam means. To this end, a longitudinal groove is cut into the arm 57, and this groove is at the lower end of rail 19 engaged by bolt 50. When tilting the brake lever 56 in clockwise direction, due to the particular guiding of the cam in arm 57, the slide 19 is automatically pulled downwardly. The displacement of the slide 19 in upward direction for restarting the rotor after the threading operation has been completed, is likewise effected automatically aided by the spring 58 which engages between a shoulder of the brake lever 56 and the spindle rail 1.

Simultaneously, the spring 58a becomes eiective which on one hand engages the brake lever 56 and on the other hand engages the housing 51. This spring 58a brings about that the housing 51 again engages the arresting portion of lever 54 so that the housing 51 will again occupy its position of operation.

FIG. l shows a modification of the positive guiding means for the slide 19. According to this modification, the lower end of slide 19 aided by the spring 59 engaging the spindle rail 1 and slide 19 moves along an inclined plane of arm 60. Arm v60 is by means of a tongue 61 engaging a groove 62 of arm l60, guided horizontally during the tilting of the brake lever 56.

The three embodiments of the brake lever according to FIGS. 8-10 have in common that a single tilting of the respective brake lever will at any rate bring about the stopping of the spindle rotor 3 in its desired rotor position. If the spindle rotor 3 after an elected threading of the thread is again to start its rotation, it is merely necessary to displace the slide 19 into the groove 20 by means of the brake lever when disengaging the brake. As a result thereof the arresting member is disengaged from groove 20 so that the spindle rotor 3 again can start rotation. During the rotation of the spindle rotor 3, the arresting member is inelective inasmuch as the arresting member is, under the effect of centrifugal force, moved outwardly.

What is claimed is:

1. A spindle structure having a stationary portion comprising an upwardly extending shaft and a rotary portion comprising a rotor surrounding said shaft, brake means operatively disposed between said portions for braking said rotary portion, and means for halting said rotor in a predetermined rotated position on said shaft, said means comprising: a recess formed in said stationary portion, a stop member carried by said rotary portion and radially moveable thereon and held against circumferential movement thereon, said stop member having a radially inner position wherein it is disposed at least partly in said recess so as to lock said rotary portion to said stationary portion in said predetermined rotated position, said stop member having a radially outer position wherein it is disposed completely out of said recess and frees said rotary portion for rotation on said stationary portion, said stop member being held in said radially outer position by centrifugal force when said rotary portion is rotating at operating speed, and a body moveably carried by said stationary portion and selectively moveable into said recess so as to displace said stop member therefrom and unlock said rotary portion from said stationary portion to permit said rotary portion to be set into rotation.

2. An arrangement according to claim 1 in which said recess is in the form of an axial recess in said shaft opening radially outwardly, and said body is in the form of a slide moveable axially of said shaft to move said body into and out of said recess.

3. An arrangement according to claim 1 in which said shaft includes a collar portion, said recess being in the form of an axial slot in said collar opening radially outwardly, said body comprising a slide movable axially of said shaft to move said body into and out of said recess, said stop member being carried by the said rotor on the inside thereof.

4. An arrangement according to claim 3 in which said rotor has a guide channel therein extending from the level of said recess upwardly and outwardly in said rotor, said stop member being movably disposed in said channel so as to extend into said recess when the rotor is at rest and to move outwardly in said channel due to centrifugal force when said rotor rotates.

5. An arrangement according to claim 3 which includes a lever pivotally connected to the inside of said rotor at one end, said stop member being connected to the other end of said lever.

6. An arrangement according to claim 3 in which said stop member is carried by said rotor at the level of said collar and is radially movable on the rotor into and out of said recess, and spring means urging said stop member in the radially inward direction of said rotor.

7. An arrangement according to claim 1 in which said stationary portion includes a rail supporting said shaft, said recess being formed in said rail at the bottom of said rotary portion, said stop member being carried by said rotor at the bottom thereof and having a vertical component of movement when moving between its radially inner and radially outer positions.

l8. An arrangement according to claim 7 in which said rotor comprises a channel in which said stop member is movably disposed, said channel extending from the bottom of said rotor in the radial range of said recess upwardly and outwardly in said rotor.

9. An arrangement according to claim 7 in which said stop member is circular in cross section and is rollable in said channel.

10. An arrangement according to claim 7 in which said stop member is pivoted to said rotor at the bottom in the radial range of said recess and extends downwardly into said recess when said rotor is stopped in said predetermined rotated position while swinging upwardly and outwardly out of the range of said recess when said rotor is rotating.

11. An arrangement according to claim 1 in which said stationary portion includes a rail supporting said shaft, a lever pivoted to said rail and operatively connected to said brake means and to said body, said lever having a first position wherein said body is disposed in said recess and said brake means is unactuated and a second position wherein said body is disposed outside said recess and said brake means is actuated.

12. An arrangement according to claim 11 which includes an arm pivoted to said lever, latch means latching said arm to a said lever in a predetermined position of the arm on the lever, an element movable on said arm and engaging and actuating said brake means upon movement of said lever into said rst position, spring means urging said element in brake means actuating direction and yieldable in response to a predetermined force exerted on said lever in brake means actuating direction, and means responsive to yielding of said spring means for releasing said latch means thereby to permit rotation of said rotor into said predetermined rotated position.

References Cited UNITED STATES PATENTS 5,364,670 1/ 1968 Stiepel et al. 57-88 3,373,556 3/1968 Stahlecker et al. 57-88 3,410,073 11/1968 Briskea et al. 57-89 JOHN PETRAKES, Primary Examiner

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