US3326341A - Variable speed control for knitting machine - Google Patents

Description

Jun 20, 967 M. SPINRAD ETAL VARIABLE SPEED CONTROL FOR KNITTING MACHINE 5 Sheets-Sheet 1 Filed Oct. 1, 1965 INVENTQR. MHLCOM SPINRHD BY BRYCE E-HOVERTERIJR- June 20, 1967 M. SPINRAD ETAL 3,326,341

VARIABLE SPEED CONTROL FOR KNITTING MACHINE Filed Oct. 1, 1965 I) Sheets-Sheet 2 INVENTOR. MHLCOM SPm RD BY BRYCE E-HOVERTERPR.

14770/P/VEK June 20, 1967 M. SPINRAD ETAL VARIABLE SPEED CONTROL FOR KNITTING MACHINE Filed Oct. 1, 1965 5 Sheets-Sheet 5 INVENTOR. Mnuzom SPmRQD BY BRYCE E. HOVEFZTEROR moT United States Patent 3,326,341 VARIABLE SPEED CONTROL FOR KNITTING MACHINE Malcolm Spinrad and Bryce E. Hoverter, Jr., Reading, Pa., assignors to American Safety Table Company, Inc., Reading, Pa., a corporation of Pennsylvania Filed Oct. 1, 1965, Ser. No. 492,229 Claims. (Cl. 192-18) This invention relates generally to speed control for knitting machines, and more particularly is directed toward speed changing for such machines by electrical control means as distinguished from mechanical pulley or gear changing or hydraulic speed changing devices.

As is well known, circular knitting machines are operated at various different speeds when different portions of a stocking are for example being knitted. By way of illustration, a relatively high speed may be employed for the knitting of welt, leg and foot portions of the stocking while a lower speed is required for heel and toe knitting. Other speeds are also required for pattern drum moves and yarn changes. In the past, speed changing has been generally accomplished by selectively utilizing one of a plurality of different speed drive pulleys, by mechanical gear shifting in a gear control box interposed between a motor or line shaft and the knitting machine drive mechanism, by providing multi-speed electrical motors together with somewhat elaborate electrical control circuitry, or by employing a fluid drive speed changing unit utilizing a fluid motor and pump.

The present invention constitutes an improvement over these systems in that the speed control mechanism is physically small, mechanically and electrically simple, quickly and easily installable to existing equipment and readily inexpensively serviceable in the field. Briefly, the invention contemplates the use of an electrically controlled clutch-brake device operatively disposed between a substantially constant speed motor or line shaft and the drive system of the knitting machine, together with a centrifugally operated governor apparatus which determines the duty cycle of the clutch device to thereby control the coupling of the constantly running motor or line shaft to the knitting machine drive system. Accordingly, it is a primary object of our invention to provide a novel apparatus for driving a rotatable shaft at any one of a number of selectable speeds from a constantly rotating input drive shaft by electrically controlling the mechanical coupling between the two shafts.

Another object of our invention is to provide a novel variable speed control apparatus as aforesaid in which the output shaft is coupled to the input shaft on a time variable basis resulting in a coupling duty cycle between 0% and 100% corresponding to an output shaft speed variable between 0% and 100% of the input shaft speed.

A further object of our invention is to provide a novel speed control apparatus as aforesaid wherein the coupling between output shaft and input shaft is mechanically effected by means of electrical control circuitry including output shaft speed monitoring means and apparatus for programming such monitor means in accordance with the desired output shaft speed at different times in the operating cycle of the work utility or apparatus driven from the output shaft.

The foregoing other objects of our invention will become clear from a reading of the following specification 3,326,341 Patented June 20, 1967 in conjunction with an examination of the appended drawings wherein:

FIGURE 1 illustrates in end elevation a knitting machine with the speed control apparatus according to the invention operatively coupled thereto;

FIGURE 2 is a vertical sectional view on an enlarged scale through the electrically controlled clutch-brake device and speed control governor portion of the apparatus according to the invention as would be seen when viewed along the line 22 of FIGURE 1;

FIGURE 3 is an end view on an enlarged scale of the rotatable portion of the speed governor device as would be seen when viewed along the line 3-3 of FIGURE 2;

FIGURE 4 is a view of the rotatable switch control portion of the apparatus shown in FIGURE 3 taken at right angles to FIGURE 3 as would be seen when viewed along the lines 44 thereof;

FIGURE 5 is an exploded perspective view of the switch controlled governor structure, a portion of which is seen in FIGURES 3 and 4, illustrating aspects not clearly visible in the sectional view of FIGURE 2; and

FIGURE 6 is a schematic electrical diagram of the entire speed control system according to the invent-ion.

In the several figures, like elements are denoted by like reference characters.

Turning now to the drawings, consider first FIGURE 1 which illustrates a knitting machine designated generally as 10, the functioning parts of which are driven from a pulley 11 by means of a drive belt 12 which latter extends downward and is trained about a pulley 13 driven through a gear reduction box 14 from a drive belt 15. As best seen from FIGURE 2, the drive belt 15 is trained about a pulley 16 fixedly secured upon a drive shaft 17 journaled by ball bearings 18 and 19 in the cup-shaped end bell 20 which is fixedly secured as by. bolts 21 to a clutch brake housing 22. The housing 22 is fixedly secured by bolts 23 to the frame 24 of an electric motor 25 so that the drive shaft 17 is axially aligned with butt end spaced from the shaft 26 of electric motor 25 which extends into the clutch-brake housing 22 and has fixedly secured upon an end thereof a flywheel 27 formed with an annular cylindrical flange 28 presenting toward the end bell structure 20.

Th end bell 20 is formed with a main wall 29 having a central hub 30 within which are held the drive shaft ball bearing supports 18 and 19. Projecting axially toward the flywheel 27 from the main Wall 29 of the end bell 20 are a pair of concentric annular cylindrical outer and inner flanges 31 and 32 respectively, an outer annular recess 33 being defined between the flanges 31 and 32 and an inner annular recess 34 being defined between the inner flange 32 and the hub structure 30 of the end bell 20. Positioned in the base of the annular recess 33 is an electrically energizable annular clutch coil 35, and similarly positioned within the annular recess 34 is an electrically energizable annular brake coil 36. Fixedly secured to the inner face of the hub 30 and within the inner cylindrical flange 32 is a brake shoe disk 37.

The inner end of drive shaft 17 has afiixed thereon for rotation therewith a hub 38 upon which is disposed for axial shifting movement with respect thereto a clutch disk 39 and a brake disk 40 provided respectively with friction facings 41 and 42. The clutch coil 35 when electrical- 1y energized sets up a magnetic flux path 43 which causes the clutch disk 39 to shift to the left on shaft hub 38 and Q engage constantly rotating motor flywheel 27 to thereby rotate the drive shaft 17 and output pulley 16. Energization of the brake coil 36 establishes the magnetic flux path 44 which shifts brake disk 40 to the right on shaft hub 38 of drive shaft 17 so that it strongly engages the brake shoe disk 37 to thereby brake the drive shaft 17 to a stop. The output pulley 16 is thus driven by the electric motor 25 when the clutch coil 35 is energized, and is braked to a stop whenever the brake coil 36 is energized.

The output pulley 16 is provided with a pulley guard 45 secured to the end bell 20 as by means of the long bolt 46. Extending outward through a central opening in the pulley guard 45 is a reduced diameter extension 47 of drive shaft 17 upon the outer end of which is fixedly secured for rotation therewith the rotor 48 of a governor device for controlling the speed of output pulleys 16. The governor rotor is engaged in an electric circuit with the governor stator 49 which is fixedly carried by a hollow generally cylindrical governor housing 50 mechanically supported by arm 51 secured to the pulley guard 45 and end bell 20 by bolt 46. The rotor and stator are enclosed by a hollow cylindrical cover cap 52 securable to the housing shell 50 by studs 53 extending from the housing through the cover cap and upon which are threaded nuts 54.

While FIGURE 2 shows the assembled organization of the governor device, detailed structural aspects of the governor are most clearly understood by referring also to FIGURES 3, 4 and 5. As best seen in FIGURE 5, the stator 49 is formed from an annular circular disk 55 of electrical insulating material, such as phenolic board, and is provided at diametrically opposite edges with holes 56 through which are projectable the studs 53 carried by the housing shell 50 so that the stator disk 55 seats fiatwise against the open annular end of the housing shell 50. Fixedly carried by the stator insulator disk 55 at radially different distances from the center of the disk are inner, intermediate and outer electrical brush holders 57, 58 and 59 respectively each carrying an electrical contact brush 60. The stator insulator disk 55 and governor housing shell 50 are centrally apertured as at 61 and 62 respectively to permit passage therethrough of the governor rotor support shaft 47 onto the end of which is projected the rotor hub 63 secured thereon by set screws 64.

As best seen from FIGURES 3, 4 and 5, the rotor 48 consists of a disk of insulating material 65 to one surface of which are fixedly secured inner, intermediate and outer conductive rings 66, 67 and 68 respectively. The conductive rings are all insulated electrically from one another and are concentric with the rotor hub 63. In the assembled governor device as seen in FIGURE 2, the brushes of brush holders 57, 58 and 59 engage respectviely with the conductive rings 66, 67 and 68. As best seen from FIG- URES 3 and 4, secured to the opposite side of the rotor insulator disk 65 are two pairs of contact assemblies designated generally as 69 and 70. The contact assembly 69 includes a first contact arm 71 electrically connected through insulator disc 65 to conductive ring 68 by metal pins 72, and a contact arm 73 electrically connected to conductive ring 67 by metal pins 74. Similarly, contact assembly 70 includes a contact arm 75 electrically connected to outer conductive ring 68 by pins 76, and a contact arm 77 electrically connected to inner conductive ring 66 by pins 78.

Each of the contact arms includes an intermediate resilient portion which allows the contact arm to flex in a direction transverse to the axis of rotor rotation, these resiliently flexible contact arm portions being designated as 71a, 73a, 75a and 77a. The arm sections 71a and 75a are somewhat more flexible than the arm sections 73a and 77a so that the centrifugal forces developed at the free ends of the contact assemblies 69 and 70 under conditions of rotor rotation cause contact arms 71 and 75 to shift outward away from the rotor hub at a different rate from that experienced by contact arms 73 and 77. Consequently, the normally closed contacts at the ends of 4 contact arms 71 and 73, as well as arms 75 and 77, are caused to separate when a sufficiently high rotor rotation has been developed to cause flexure of contact arm sections 71a and 75a.

Since, with the contacts of contact assembly 69 engaged with one another electrical continuity is maintained between conductive rings 67 and 68 of the rotor, and since this electrical continuity can be broken by causing the contacts of contact assembly 69 to separate when the rotor 48 is rotated at some particular speed, it is apparent that an external electrical circuit connected to the contact assembly through the conductive rings 67 and 68 can be controlled by the speed of the rotor so that circuit continuity exists below a predetermined rotor speed when the contact assembly is closed, and is broken above the predetermined rotor speed when the contacts are open. Similarly, contact assembly 70 functions to control an external electrical circuit connected to rotor conductive rings 66 and 67.

The particular rotor speeds at which contact assemblies 69 and 70 are caused to open their contacts may be selectively controlled by means of adjustment cones 79 and 80 respectively. Each of the cones 79 and 80 is externally threaded and physically supported in a mount carried by the rotor insulator disk so that the pointed end of the cone 79 bears laterally against the contact arm 73 of contact assembly 69 while the cone 80 is similarly disposed with respect to the contact arms 77 of contact assembly 70. Rotation of the cones causes the contact arms 73 and 77 to be shifted outward away from the rotor hub 63 and to thereby also carry outward the contact arms 71 and 75. Such outward movement of contact arms 71 and 75 corresponds of course to progressively higher speeds of rotation of the rotor 48 so that when for example contact arm 71 has been mechanically outwardly shifted by cone 79 to a position which it would not assume until the rotor speed had reached a certain value, then it follows that further outward movement of contact arm 71 will not occur until the actual rotor speed exceeds such value. Thus, the cones 79 and 80 may be used to set the rotor speeds at which the contact assemblies 69 and 70 will open.

With two contact assemblies set to open at different speeds, it is clear that three discrete rotor speed ranges may be established, the-first speed range being below the break point of either contact assembly, the second range being above the break speed of one contact assembly but below that of the other, and the third range being above the break speed of the second contact assembly. Similarly, four speed ranges may be provided with three contact assemblies, and so forth as desired.

Recalling from FIGURE 2 that the output pulley 16, and hence the drive belt 15, is coupled to the constantly rotating motor flywheel 27 by the clutch disk 39 when the clutch coil 35 is energized, it will now be understood that three different rotational speeds of output pulley 16 may be provided for by controlling the energization of clutch coil 35 in conjunction with the use of governor contact switch assemblies 69 and 70. By way of illustration, high speed operation of the pulley at the flywheel rate is provided for by constant energization of clutch coil 35 in a circuit which completely bypasses the governor device. Medium speed operation is provided for by energization of the clutch coil 35 through one of the contact assemblies, say contact assembly 70, at a speed determined by the mechanical setting of rotor control cone 80. Low speed operation is provided for by controlling energization of the clutch coil 35 through governor contact switch assembly 69 at a speed determined by rotor carried adjustment cone 79.

Assuming that the continuous flywheel speed provided by electric motor 25 is approximately 1750 revolutions per minute and it is desired to operate the knitting machine 10 at a top speed of approximately 440 revolutions per minute, then the gear reducer 14 would be chosen to provide a four to one speed reduction. Further, if the intermediate and low speed of the knitting machine are desired to be approximately 250 rpm. and 125 rpm, then intermediate speed governor contact assembly 70 would be adjusted to open when the rotational speed of output pulley 16 becomes 1000 rpm. while the low speed control governor contact assembly 69 would be adjusted to open at an output pulley speed of 500 rpm. Substantially constant machine speed is maintained by rapid opening and closing of the particular operative contact assembly of the governor to cause continual declutching from and reclutching to the high speed motor flywheel 27 at the rate required. This operation is automatic since a rise in output pulley speed above the desired level opens the governor contact assembly to declutch from the flywheel and permit the output pulley speed to begin to coast downward. As soon as the output pulley speed drops below the contact assembly preset speed, the contact assembly recloses and again clutches the output pulley into the high speed flywheel to increase the output speed. This cyclic operation maintains the machine speed substantially constant at the desired pressure value.

Refer now to FIGURE 6 which illustrates in schematic form the electrical control circuitry operative to provide speed control for a device such as the knitting machine by means of the apparatus according to the invention as shown in FIGURES 2 through 5. Alternating electrical current is 1 provided from a source of electrical energy through the transformer 81 to the bridge rectifier 82. The positive terminal of rectifier 82 is connected via conductor 83 to a current controlling rheostat 84 which is in turn connected via conductor 85 to one end of clutch coil 35 and brake coil 36, each of the clutch and brake coils being shunted by a reversely poled diode 86. The opposite terminal of clutch coil 35 is connected via conductor 59a, its associated brush assembly 59 and rotor conductive ring 68 to contact arms 71 and 75 of rotor contact assemblies 69 and 70, while also being connected via conductor 87 to one contact 88 of a single pole double throw switch having a second contact 89 and pole 90. The switch contact 89 is connected via governor brushholder conductor 57a and rotor conductive ring 66 to contact arm 77 of rotor contact assembly 70. Pole 90 of control switch 91 connects via conductor 92 to one contact 93 of a second single pole double throw control switch 94 having a second contact 95 and a pole 96, the second contact 95 being connected via conductor 58a and the associated governor brush holder 58, brush 60 and conductive ring 67 to contact arm 73 of rotor contact assembly 69.

Pole 96 of control switch 94 connects via conductor 97 to a normally closed contact 98 of a relay 99 having three poles 100, 101 and 102, contact 98 being engaged by pole 101 when relay 99 is in its deenergized condition. When relay 99 is energized so that the poles thereof transfer, pole 101 disengages from contact 98 and engages contact 103 which is connected via conductor 104 to the end of brake coil 36 which is not connected to conductor 85. Relay poles 100 and 102 are both normally open circuits when relay 99 is deenergized, engaging respectively with contacts 105 and 106 when the relay becomes energized to transfer its poles.

Relay poles 101 and 102 are electrically tied together and commonly connected to one side of start switch 107 via conductors 108 and 109, the other side of start switch 107 being returned to the negative side of DC. power supply 82 through normally closed brake release switch 110 and conductor 111. Relay contact 105 returns to the negative side of rectifier 82 through pilot light 112, while relay contact 106 connects to one side of relay coil 113 and also to one side of each of a plurality of normally open switches 114 through 117, the switches being connected in parallel and having their opposite terminals commonly connected through conductor 118 to conductor 109. The end of relay coil 113 not connected to relay contact 106 is connected via conductor 119 to the positive terminal of rectifier 82.

The clutch coil 35 and brake coil 36 are of course physically located inside the housing 22 shown in FIGURE 2, the contact assemblies 69 and 70 are located in the governor device also shown in FIGURE 2, and the control switches 91 and 94 are part of the knitting machine 10 and are caused to transfer their poles at appropriate times during the cycle of machine operation to effect changes in machine speed appropriate to the particular machine operation at that point being carried out. Typically, these control switches 91 and 94 may be actuated and deactuated by machine controlled rotating cams. The switches 114 through 117 are also associated with the knitting machine 10 and are typically cam operated to be selectively closed when it is desired to stop the machine, for example upon breakage of a needle or thread, when the machine is to operate for a single cycle, or for some other stop motion function. The switches 107 and 110, rheostat 84, relay 99 and the power supply may be conveniently located at any desired point, which usually will be at the machine itself.

Consider now that the circuit is as indicated in FIG- URE 6 with start switch 107 open and control switches 91 and 94 in their solid line positions as illustrated, The knitting machine 10 is quiescent the clutch coil 35 and brake coil 36 are deenergized but the electric motor 25 is energized so that flywheel 27 is rotating at its constant speed of substantially 1750 revolutions per minute. Closure of start switch 107 causes current to flow from rectifier 82 through conductor 83 and rheostat 84 to clutch coil 35, over conductor 87 and through control switches 91 and 94 to contact 98 and pole 101 of relay 99, thence over conductors 108 to 111 through switch 107 and 110 to rectifier 82.

With clutch coil 35 energized, clutch disk 39 is pulled into engagement with flywheel 27 and output pulley 16 is driven at the full flywheel speed corresponding to high speed operation of the knitting machine 10. With the machine operating, assume that control switch 91 is caused to transfer its pole from contact 88 to contact 89 so that energization of clutch coil 35 can no longer occur over conductor line 87 but must take place via conductor 5911, contact assembly 70 of the speed governor and conductor 57a. Since contact assembly 70 is for purposes of illustration to cause output pulley 16 to be driven at a rate of 1000 revolutions per minute, it is clear that the substantially higher flywheel rate of 1750 revolutions per minute has necessarily caused the contact arms 75 and 77 to disengage and prevent energization of clutch coil 35. Consequently, the clutch is disengaged and output pulley 16 immediately slows down due to the load imposed thereon by the knitting machine 10. As soon as the pulley speed has dropped to the 1000 rpm. level, contact assembly 70 closes to reenergize clutch coil 35 and control the speed of output pulley 16 in the manner previously described.

Assuming now that it is desired to further reduce the machine speed for yet a different type of machine operation to the low speed 500 rpm. range, control switch 94 is caused to transfer its pole 96 from contact 93 to contact to thereby remove control of clutch coil energization from governor contact assembly 70 and transfer such control to contact assembly 69. In this manner changes in machine speed are effected throughout the cycle of machine operation by selectively transferring the poles of the control switches 91 and 94.

When the machine has completed its operation, a stop motion switch such as 114 is caused to automatically close and thereby enable current to flow from rectifier 82 through conductor 119, relay coil 113, switch 114 and conductor 118 back to conductor 109 and hence to the return side of rectifier 82. Relay 99 is thereby actuated causing poles 100, 101 and 102 to respectively engage contacts 105, 103 and 106. .Disengagement of relay pole 101 from contact 98 breaks the circuit continuity to clutch coil 35 to thereafter prevent any clutching operation, and engagement of pole 101 with contact 103 energizes brake coil 36 to thereby immediately brake output pulley 16 to a halt. Engagement of pole 100 with contact 105 lights pilot light 112 to indicate a stop condition of the machine. Engagement of relay pole 162 with contact 106 establishes a holding current circuit for relay coil 113 to maintain the relay energized under conditions where it may be desirable to utilize switches of the momentary-make type as one or more of the switches 114 through 117. With the machine stopped the brake coil 36 may be deenergized by opening the brake release 110. This of course also deenergizes relay 99 and reestablishes the relay conditions illustrated in FIGURE 6.

Having now described our invention in connection with a particularly illustrated embodiment thereof it will be appreciated that modifications and variations of our invention may now naturally occur from time to time to those persons normally skilled in the art without departing from the essential scope or spirit of our invention, and accordingly it is intended to claim the same broadly as well as specifically as illustrated by the appended claims.

What is claimed to be new and useful is:

1. Speed control apparatus for controlling the operating speed of a Work utility which is is desired to drive an any of a plurality of selectable different speeds from, a constant speed primary drive source, comprising in combination,

a power transmission having a rotary input drive shaft connectable to a constant speed drive source, a roa tary output drive shaft connectable to the work utility to drive the latter, and an electrically actuatable clutch effective when actuated for coupling the rotary output drive-shaft to the rotary input driveshaft, said speed control apparatus comprising in combination,

speed selection electric switch means for selecting any one of a plurality of different speeds at which it is desired to operate a work utility, and speed sensing electric switch means connected in electric circuit with the electrically actuatable clutch and a source of electric power, said speed sensing switch means being operatively coupled to the power trans-mission rotary output drive shaft for simultaneous rotation therewith and responsive to departure of the output drive shaft rotational speed from the selected desired speed to alter the electric circuit conditions to thereby actuate said clutch means whenever the output drive shaft rotational speed drops below said desired speed and to deactuate the clutch means whenever the output drive shaft rotational speed rises above the selected desired speed.

2. The speed control apparatus as set forth in claim 1 wherein said speed selection switch means further includes means for locking out of said electric circuit said speed sensing switch means and simultaneously continuously actuating the clutch independently of said speed sensing switch means.

3. The speed control apparatus as set forth in claim 1 wherein said speed selection switch means is coupled to and automatically opera-ted by means associated with said work utiilty to thereby provide automatic programmed work utiilty speed selection.

4. The apparatus as set forth in claim 1 wherein the power transmission further includes output drive shaft selectively actuatable brake means, and wherein said speed control apparatus further includes selectively operable means coupled to the actuatable brake means effective when operated to actuate the brake means and quickly brake to a stop the power transmission output drive shaft.

5. Speed control apparatus for controlling the operating speed of a work utiilty which it is desired to drive at any of a plurality of selectable different speeds from a constant speed primary drive source, comprising in combination,

C? o a power transmission having a rotary input drive shaft connectable to a constant speed drive source, a rotary output drive shaft connectable to the work utility to drive the latter, and an electrically actuatable clutch effective when actuated for coupling the r0- tary output drive-shaft to the rotary input drive-shaft, said speed control apparatus comprising in combination,

(a) a speed control governor including a rotor and a stator, said rotor being mechanically couplable to the transmission output drive shaft for simultaneous rotation therewith and including (1) speed responsive electric switch means having openable and closable contacts mounted laterally of the rotor rotational axis and so oriented with respect thereto that changes in the centrifugal force exerted on said contacts developed by changes in rotor rotation rate cause the state of said switch contacts to change between closed state and open state,

(2) adjustable means engaged with said electric switch means effective to set the rotor rotation rate at which said switch means contacts change state, and

(3) a plurality of separate electrically conductive rings each of which is electrically connected to a different one of said switch contacts and concentric with the axis of rotor rotation,

said stator being mechanically fixedly positioned adjacent to said rotor and carrying individual electrical contacts each of which is electrically engaged with a different one of said rotor conductive rings,

(b) speed selection electric switch means connected in electric circuit through said stator contacts with said rotor carried speed responsive switch means and connectable with the electrically actuatable clutch and a source of electric power effective to selectably render said speed responsive switch means operative and inoperative for controlling the actuation of the electrically actuatable clutch,

said speed responsive switch means when operative being effective to alter the electric circuit conditions to actuate the clutch whenever the output drive shaft rotational speed drops below said selected speed and being effective to deactuate the clutch whenever the output drive shaft rotational speed rises above the selected speed.

6. The apparatus as set forth in claim 5 wherein said rotor carried speed responsive electric switch means includes at least two independent switches and wherein said adjustable means engaged therewith includes means for independently setting the rotor rotation rates at which the contacts of each rotor switch change state.

7. The apparatus as set forth in claim 5 wherein said rotor carried speed responsive electric switch means includes at least two independent switches and wherein said adjustable means engaged therewith includes means for independently setting the rotor rotation rates at which the contacts of each rotor switch change state, and wherein said speed selection switch means is coupled to and automatically operated by means associated with said work utility to thereby provide automatic programmed work utility speed selection.

8. The apparatus as set forth in claim 5 wherein said speed selection switch means renders the clutch continuously actuated Whenever said speed responsive switch means is rendered inoperative by said speed selection switch means.

9. The apparatus as set forth in claim 5 wherein the power transmission also includes output drive shaft selectively actuatable brake means, and wherein said apparatus further includes selectively operable control means coupled to the actuatable brake means effective when operated to actuate the brake to quickly brake to a stop the output drive shaft.

10. The apparatus as set forth in claim 5 wherein the power transmission also includes an output drive shaft selectively electrically actuatable brake, and wherein said apparatus further includes selectively operable control means in electric circuit with the electrically actuatable brake and clutch effective when operated to actuate the brake and deactuate the clutch to quickly brake to a stop said output drive shaft.

References Cited UNITED STATES PATENTS Grifiin 192-103X Edwards 192-18.2 Neal 200-80 Shepard 192-l8.2 Myers 192-18.2X Schwartz et a1. 200-80 MARK NEWMAN, Primary Examiner.

ARTHUR T. MCKEON, Examiner.

Disclaimer 3,326,341.-Mal00m Spinmd and Bryce E. Hoverter, J12, Reading Pa. VARI- ABLE SPEED CONTROL FOR KNITTING MACHINE. Patent dated June 20, 1967. Disclaimer filed May 28, 1969, by the assignee, American Safety Table Company, Inc. Hereby enters this disclaimer to claims 1, 2, 4, 5, 6, 8, 9 and 10 of said patent.

[Oyficz'al Gazette October 14, 1.969.]

Claims (1)

1. SPEED CONTROL APPARATUS FOR CONTROLLING THE OPERATING SPEED OF A WORK UTILITY WHICH IS IS DESIRED TO DRIVE AN ANY OF A PLURALITY OF SELECTABLE DIFFERENT SPEEDS FROM A CONSTANT SPEED PRIMARY DRIVE SOURCE, COMPRISING IN COMBINATION, A POWER TRANSMISSION HAVING A ROTARY INPUT DRIVE SHAFT CONNECTABLE TO A CONSTANT SPEED DRIVE SOURCE, A ROTARY OUTPUT DRIVE SHAFT CONNECTABLE TO THE WORK UTILITY TO DRIVE THE LATTER, AND AN ELECTRICALLY ACTUATABLE CLUTCH EFFECTIVE WHEN ACTUATED FOR COUPLING THE ROTARY OUTPUT DRIVE-SHAFT TO THE ROTARY INPUT DRIVESHAFT, SAID SPEED CONTROL APPARATUS COMPRISING IN COMBINATION, SPEED SELECTION ELECTRIC SWITCH MEANS FOR SELECTING ANY ONE OF A PLURALITY OF DIFFERENT SPEEDS AT WHICH IT IS DESIRED TO OPERATE A WORK UTILITY, AND SPEED SENSING ELECTRIC SWITCH MEANS CONNECTED IN ELECTRIC CIRCUIT WITH THE ELECTRICALLY ACTUATABLE CLUTCH AND A SOURCE OF ELECTRIC POWER, SAID SPEED SENSING SWITCH MEANS BEING OPERATIVELY COUPLED TO THE POWER TRANSMISSION ROTARY OUTPUT DRIVE SHAFT FOR SIMULTANEOUS ROTATION THEREWITH AND RESPONSIVE TO DEPARTURE OF THE OUTPUT DRIVE SHAFT ROTATIONAL SPEED FROM THE SELECTED DESIRED SPEED TO ALTER THE ELECTRIC CIRCUIT CONDITIONS TO THEREBY ACTUATE SAID CLUTCH MEANS WHENEVER THE OUTPUT DRIVE SHAFT ROTATIONAL SPEED DROPS BELOW SAID DESIRED SPEED AND TO DEACTUATE THE CLUTCH MEANS WHENEVER THE OUTPUT DRIVE SHAFT ROTATIONAL SPEED RISES ABOVE THE SELECTED DESIRED SPEED.

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