Abstract:
A variable speed control device operatively connected between the wheel of the longitudinally movable frame of a cloth spreading machine and a cloth feed roll on the frame, including a pair of variable pitch pulleys linked by an endless belt, and a manually operable control member for simultaneously varying inversely the diameters of the pulleys in order to change the relative speed of the cloth feed roll and the linear speed of the machine frame. 
     The variable speed control device also includes a clutch control device for selectively engaging and disengaging the drive between the frame wheel and the cloth feed roll.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a cloth feed control for a cloth spreading machine, and more particularly to a variable cloth feed speed control for a cloth spreading machine. 
     In the operation of cloth spreading machines, longitudinally and reciprocally movable over a cutting table, and including a driven cloth feed roll for feeding a web of cloth from a cloth supply to and along the cutting table as the machine frame moves over the cutting table, the relative speed of the cloth feed and the frame movement is critical in order that the cloth may be spread upon the table and upon the preceding layers of cloth with a minimum of stretching or wrinkling. 
     Various types of cloth feed controls for cloth spreading machines are know in the art. Many such controls utilize dancer rolls or other sensors for detection of slack loops of cloth, or the cloth feed speed is corrected by manual adjustment during the progress of the cloth spreading operation. These various detection and control methods actuate electrical motors or motor controls to stop and start the cloth feed when desired, or vary the electrical resistance in a motor speed control in order to continually change the speed of the cloth feed roll, so that it conforms with the linear speed of the machine frame. 
     Examples of some of the prior art cloth feed control mechanisms are disclosed in the following U.S. patents: 
     
         ______________________________________3,400,927    Martin Sr., et al                       Sept. 10, 19683,663,006    Benson et al   May 16, 19723,684,273    Benson et al   Aug. 15, 19723,727,907    Martin Sr., et al                       April 17, 19733,782,649    Frederick et al                       Jan. 1, 1974______________________________________ 
    
     SUMMARY OF THE INVENTION 
     In order to provide a gradual and infinitely adjustable system for controlling the relative speed of the cloth web and the spreading machine frame, the variable cloth feed speed control device made in accordance with this invention includes a system of mechanical elements which may be finely adjusted manually by the operator as the machine moves along the cutting table. 
     Specifically, the speed control device made in accordance with this invention includes a pair of variable pitch pulleys, an input pulley and an output pulley, linked by an endless belt. The shaft of the input pulley is coupled through a drive transmission, such as a sprocket and chain transmission, to one of the wheels of the frame so that as the frame moves longitudinally over the cutting table, the drive from the wheel is transmitted to the input shaft of the input pulley. The shaft of the output pulley is connected through an output drive transmission to the cloth feed roll. 
     An elongated speed control shaft has a first screw feed mechanism connected to the axially movable flange of the output pulley so that rotation of the control shaft causes the flange to move toward or away from the output pulley, depending upon the direction of rotation of the control shaft. The axially movable flange of the input pulley is also connected to a second screw feed mechanism, which in turn is linked by a transmission, such as a gear transmission, to the control shaft, so that the rotation of the control shaft in one direction to axially shift the output pulley flange toward the belt, will simultaneously cause the axially movable flange of the input pulley to move away from the belt, and vice versa. By virtue of this control mechanism, the flanges of the input and output pulleys can be varied incrementally in opposite directions for very fine adjustments of the relative speed between the machine frame and the cloth feed roll. 
     A second control shaft is provided for axial movement to axially shift a clutch member along the output pulley shaft for operative engagement or disengagement with a corresponding clutch face on a freely rotary driven member, such as a sprocket, on the output pulley shaft, in order to selectively connect the cloth feed roll drive to the input drive produced by the movement of the machine frame. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation of a cloth spreading machine including a variable cloth feed speed control apparatus made in accordance with this invention; 
     FIG. 2 is a fragmentary top plan view of the cloth spreading machine disclosed in FIG. 1, with portions broken away; 
     FIG. 3 is an enlarged fragmentary plan view of the cloth feed speed control apparatus, with portions broken away; 
     FIG. 4 is a schematic section, taken along the line 4--4 of FIG. 3, disclosing the gear train arrangement; 
     FIG. 5 is a fragmentary section, taken along the line 5--5 of FIG. 1, with portions broken away; 
     FIG. 6 is a fragmentary section, taken along the line 6--6 of FIG. 3; and 
     FIG. 7 is a section, taken along the line 7--7 of FIG. 6. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings in more detail, FIGS. 1 and 2 disclose a cloth spreading machine 10 including a frame or machine 11 supported by wheels, such as the smooth-surfaced wheels 12 and 13 on the remote side of the frame 11, shown in FIG. 1, for rolling movement over the top surface of a spreading or cutting table 14. 
     Mounted on top of the machine frame 11 is a cloth supply carriage 16 in the form of a turntable mounted for rotary movement about the vertical axis of the hollow shaft 17. 
     Mounted at opposite sides of the carriage 16 are a pair of cloth roll support standards 20, which support a spindle 21 upon which is wound a cloth supply roll 22. 
     From the cloth supply roll 22 a web of cloth 23 passes beneath a transverse guide bar 25, over a cloth feed roll 26 mounted on one end of the carriage 16, and then down through an edge sensor 27 and through a conventional spreader unit 28. The spreader unit 28 spreads or lays the web 23 upon the surface of the cutting table 14 in layers 30 (FIG. 1), as the machine frame 11 reciprocates longitudinally on a predetermined course over the cutting table 14. 
     As best disclosed in FIG. 1, an electrical motor 35 may be mounted on a machine frame 11 to drive a gear reducer 36, through shaft coupling 37. The rear reducer 36 drives the wheel drive shaft 38 through sprocket and chain transmission 39. Power from the wheel drive shaft 38 is transmitted to the wheel 13 through sprocket and chain transmission 40. The electrical motor 35 may be provided with power from any convenient source, not shown, and controlled in any conventional manner. 
     The front wheel 12 is operatively connected by a chain and sprocket transmission 42 to a direction compensator or unidirectional gear box 43. Thus, regardless of the direction of rotation of the front wheel 12, the gearing and transmission within the unidirectional gear box 43 will produce the unidirectional rotary output. In other words, the rotary output shaft 44 on the unidirectional gear box 43 will always rotate in the same direction, regardless of the rotary direction of the wheel 12. However, the rotary speed of the output shaft 44 will be commensurate or proportional to the speed of the table wheel 12. The unidirectional output shaft 44 is connected through a sprocket and chain transmission 45 to the input shaft 46 of an input variable pitch pulley 47 in the variable speed control device 48, made in accordance with this invention. 
     The variable pitch input pulley 47 has a V-shaped groove defined by a fixed flange 49 and an axially shiftable flange 50. The axially shiftable flange 50 is fixed to the hub 51 rotatably coupled to a screw feed shaft 52, which is threaded for axial movement within a fixed screw feed housing 53. 
     The variable speed control device 48 includes an output shaft 55 fixed to a variable pitch output pulley 56 including a fixed flange 57 and an axially shiftable flange 58 defining an annular V-shaped groove of variable diameter. The axially shiftable flange 58 is fixed to a hub 59, which is rotatably coupled to an elongated speed control shaft 60, extending the full width of the machine frame 11. The control shaft 60 has a threaded portion 61 threadedly engaging a nut member 62 on the operator side of the machine 10 to provide axial feeding movement of the control shaft 60 in either axial direction. The extremity of the control shaft 60 is provided with a handle 63 for manually rotating the shaft 60 in either rotary direction. 
     The control shaft 60 is rotatably linked to the screw feed shaft 52 through the gear train 65, including four intermeshing spur gears, as illustrated in FIGS. 3 and 4. The left spur gear in the train 65 in FIG. 3 is fixed to the screw feed shaft 52 to move axially therewith. However, the axial travel of the left spur gear is so limited, that it always remains enmeshed with the next cooperating spur gear in the gear train 65. In like manner, the right spur gear in FIG. 3 moves axially with the control shaft 60, without losing meshing engagement with the adjacent cooperating spur gear in the gear train 65. 
     Thus, when the handle 63 is rotated in one direction, the screw feed shaft 52 is rotated in the opposite direction to simultaneously cause the axially movable flanges 58 and 50 to shift axially in opposite directions, thus increasing the diameter of one of the pulleys 47 or 56, while decreasing the diameter of the other pulley 56 or 47. The pulleys 47 and 56 are linked by an endless belt 66. 
     Of course, when the control shaft 60 is counter-rotated in the opposite direction, the screw feed shaft 52 will be rotated in the reverse direction, which is the direction opposite to the rotation of the control shaft 60, in order to reverse the directions of axial movement of the shiftable pulley flanges 50 and 58. 
     Carried on the outer portion of the output shaft 55 for free rotatable movement is a clutch sprocket 68 carrying a chain 69 trained about the sprocket 70 fixed to shaft 71 extending transversely of, and journaled for rotary movement in, the frame 11. The inner end of the shaft 71 terminates in a bevel gear 72 meshing with another bevel or miter gear 73 disposed at right angles and fixed to a vertical rotary shaft 74 within the hollow turntable shaft 17. The rotary shaft 74 terminates at its upper end in in another bevel or miter gear 75. The bevel gear 75 meshes with bevel gear 76 fixed at the inner end of another transverse shaft 77, journaled in the turntable carriage 16, and terminating at its outer end in a sprocket 78. The sprocket 78 is coupled through chain 79 to sprocket 80 fixed to the shaft of the driven cloth feed roll 26. Thus, through this drive transmission from the output shaft 55 to the cloth feed roll 26, the drive is uninterrupted, even through the turntable 16 is rotated about its vertical axis relative to the machine frame 11 to position the cloth feed roll 26 optionally at either end of the cloth spreading frame 11. 
     In order to selectively engage and disengage the drive for the cloth spreading frame 11 and the cloth feed roll 26, a clutch disc 82 is axially slidable, but rotatably fixed, on the outer end of the output shaft 55 of the variable speed control device 48. The clutch disc 82 is provided with an axially projecting tongue or lug 83 which is adapted to engage a corresponding recess 84 in the clutch sprocket 68, when the clutch disc 82 is thrust axially inwardly along the output shaft 55 by a spring 85. 
     The clutch disc 85 is pivotally connected to a link arm 86, the intermediate portion of which is pivoted to a fixed bracket 87 on the machine frame 11 by a pivot pin 88. The opposite or rear end portion of the link arm 86 is pivotally connected by pin 89 to a transversely extending, and axially shiftable, clutch control rod or shaft 90. The clutch control rod 90 extends the full width of the machine frame 11, projecting from the operator&#39;s side of the frame 11 and terminating in a clutch control knob or handle 91. When the control knob 91 is pulled outboard of the machine frame 11 by the operator, the clutch disc 82 is shifted axially outboard on the opposite side of the machine frame 11 to disengage the clutch tongue 83 from the recess 84 to disengage the drive transmission between the motor 35 and the cloth feed roll 26. 
     The manual control knob 91 may be retained in its outboard position by rotation of the knob 91 through a predetermined angle so that the diametrical ears 92 will be rotated out of registry with a corresponding pair of recesses 93 in a journal housing 94 for the clutch control rod 90, as best illustrated in FIGS. 6 and 7. By counter-rotating the knob 91 so that the ears 92 will register with the recesses 93, the handle 91 may be released to permit the spring 85 to thrust the clutch disc 82 back into driving engagement with the clutch sprocket 68. 
     In the operation of the cloth spreading machine 10, the machine frame 11 is driven over the cutting table 14 in a direction, such as the forward direction indicated by the arrow 95 in FIG. 1, by energization of the motor 35. As the machine frame 11 is moving along the table 14, the front wheel 12 is rotated to cause the variable pulleys 47 and 56 to rotate in a direction for driving the cloth feed roll 26 to feed the cloth web 23 down toward the table 14 for spreading, when the clutch disc 82 engages the clutch sprocket 84, as illustrated in FIG. 2. 
     If the cloth web 23 is being fed too fast relative to the table speed of the machine frame 11, then the operator walking alongside the machine 10 grasps the control shaft handle 63 and rotates it in a direction which will cause the opposite axial shiftable movement of the pulley flanges 50 and 58, which will reduce the speed of the cloth feed roll 26. 
     If the cloth 23 is being fed too slowly, then the control shaft handle 63 will be rotated in the opposite direction until the speed of the cloth will be commensurate with the speed of the machine frame, so that the cloth web 23 will be laid flat on the cutting table 14, or on the next subjacent layer of cloth in the stack 30 on the cutting table 14, without tension or slack. 
     Because of the construction of the variable speed control device 48, including the screw-feed structure 61-62 of the control shaft 60 and the screw feed shaft 52, the axial opposite shifting of the flanges 50 and 58 can be carried out incrementally with very fine adjustments. 
     These adjustments may be made regardless of the position of the cloth feed roll 26, that is whether the cloth feed roll 26 is spreading on the front end of the frame 11 or whether it has been rotated about the shaft 74 through 180° for spreading cloth at the rear end of the frame 11. 
     Moreover, at any time when it is desired to move the spreading frame 11 without spreading cloth, the operator may withdraw the clutch control knob 91 outboard to disengage the clutch disc 82 from the clutch sprocket 84.