US3663006A

US3663006A - Electrically controlled cloth spreading machine

Info

Publication number: US3663006A
Application number: US857509A
Authority: US
Inventors: Robert W Benson; James Ronald Chapman; Robert G Reed; Hoyt L Smith
Original assignee: Cutters Machine Co Inc
Current assignee: Saber Industries Inc
Priority date: 1969-09-12
Filing date: 1969-09-12
Publication date: 1972-05-16
Anticipated expiration: 1989-05-16
Also published as: GB1320517A; GB1320516A; GB1320518A; CA924799A; DE2044754A1; GB1320515A; DE2044754C2

Abstract

An electrically driven and controlled cloth spreading machine including means for reversing the travel of the machine, means for controlling the high and low speeds of the machine, means for causing the machine to fail safe at low speed upon power failure and open circuit conditions caused by different changes in function of the machine. The machine is also provided with various selective controls for manual, semi-automatic and automatic operation of the machine, and for spreading cloth face-to-face, face-up or face-down.

Description

United States Patent Benson et al.

[ 1 May 16, 1972 11/1969 Martin, Sr. et al ..270/3l 9/1970 Merrill ..270/31 Primary Examiner-Robert W. Michell Assistant Examiner-L. R. Oremland Attorney-Harrington A. Lackey [57] ABSTRACT An electrically driven and controlled cloth spreading machine including means for reversing the travel of the machine, means for controlling the high and low speeds of the machine, means for causing the machine to fail safe at low speed upon power failure and open circuit conditions caused by different changes in function of the machine.

The machine is also provided with various selective controls for manual, semi-automatic and automatic operation of the machine, and for spreading cloth face-to-face, face-up or facedown.

7 Claims, 4 Drawing Figures PATENTEDMAY 15 I972 SHEEI 1 [IF 2 QIUUUUUUYJUUUITU I I I I I Ill 1' II 9. mime 530m III/II If INVENTORS: ROBERT WBENSON Jnmas RONALD CHAPMAN ROBERT G. REED HOV L-ISMITH ATTORNEY Wow Kw Kw ELECTRICALLY CONTROLLED CLOTH SPREADING MACHINE BACKGROUND OF THE INVENTION This invention relates to a cloth spreading machine, and more particularly to a versatile, electrically operated cloth spreading machine.

Cloth spreading machines, and even electrically operated cloth spreading machines are known in the art. Also, cloth spreading machines have been developed, and are now in operation, which travel at high speed over the major portion of their reciprocable course between a pair of reversing stations and in low speed adjacent the reversing stations for cooperative engagement with the catcher mechanism to form folds in the ends of the layers of cloth. However, in order to minimize damage to the machine and cloth and jerking and irregular folding of the cloth at the reversing stations, various electrical switch controls have been adopted in order to reduce the speed of the machine just prior to its cooperation with the catcher mechanism. It is also known to resume the high speed of the machine as soon as possible after it has reversed its movement and formed the fold in the layer of cloth.

Difficulty has been experienced with speed controls for cloth spreading machines, either because of the reliability of the controls, or because of the lack of skill of the operators of the machine. Thus, on occasions, a spreading machine has been known to enter the catcher mechanism and reversing station at high speeds, and sometimes without reversing.

SUMMARY OF THE INVENTION It is therefore an object of this invention to provide an electrically driven cloth spreading machine provided with various electrical controls to cause the machine to fail safe in low speed.

The spreading machine made in accordance with this invention is provided with an electrical motor drive, a reversible motor circuit, a motor speed control apparatus, and reversing and speed change switches adapted to be actuated at appropriate stations to permit the reduction of the speed of the spreading machine as it approaches its reversing station, to permit reversing of the machine at each end of its travel, and to resume its high speed within a short distance of the reversing station as the machine resumes its spreading operation. The high speed switches are designed to momentarily close to energize a holding relay circuit which will maintain the machine at high speed as long as the holding relay circuit is energized. However, upon any interruption of current to the holding relay circuit, the speed of the machine will automatically be reduced.

A further object of this invention is to provide a time-delay circuit which will automatically brake the machine every time the speed of the machine is reduced from high to low, to reduce the deceleration time, and therefore decrease the production time, of the machine.

This invention further contemplates circuitry which permits selective face-to-face cloth spreading, or face-down or face up spreading. In either the face-down or the face-up spreading operation, an automatic braking mechanism is provided to stop the machine after each layer of cloth is spread, so the cloth may be cut. The circuitry also provides means for manually re-starting the machine in its reverse direction to the opposite end of the course, without laying cloth, preparatory to laying the next layer of cloth.

The machine made in accordance with this invention also is provided with a remote control handle incorporating a starting switch, and a re-starting switch for face-up or face-down spreading, to afford the operator of the machine the opportunity of viewing the spreading operation from the front of the machine while still being in full control of the machine.

The invention also contemplates the provision of an automatic mechanism for overfeeding the cloth web to accommodate the extra cloth demand created by the interaction of the spreading unit with the catcher mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a cloth spreading machine made in accordance with this invention adjacent a catcher mechanism at one end of the travel of the machine;

FIG. 2 is an enlarged sectional elevation of the plunger-actuated switch mechanism mounted on the front of the machine;

FIG. 3 is an enlarged sectional elevation of the cloth overfeed mechanism; and

FIG. 4 is a schematic circuit diagram of the electrical drive and control system for the machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to the drawings, FIG. 1 dis closes a cloth spreading machine 10 made in accordance with this invention, including a carrier frame 11 supported by

wheels

12 and 13 for longitudinal movement along a spreading table 14. A cloth supply roll 15 is supported for free rotary movement upon standards 16 mounted upon the frame 11 for unwinding and feeding a web of cloth 17. In the machine 10, the web 17 is threaded through an edge control device 18, beneath a pivotally mounted cloth tension rod 19 and then over a driven top feed roll 20. The web 17 then depends through a cloth spreader frame or unit 21, having tuck blades or spreader blades, not shown, for spreading the cloth web l7 in layers 22 upon the table 14. A catcher mechanism 24 including a catcher bar 25 is stationed upon the spreading table 14 at one end of the travel or course of the carrier frame 11 to cooperate with the spreader unit 21 in a well known manner to fold theend of each cloth layer 22.

An electrical motor 28 mounted on the frame 11 is operatively connected to drive the left rear wheel, not shown, which is connected by suitable chain and sprocket mechanism, not shown, to transverse drive shaft 29, which in turn is coupled through suitable sprocket end chain mechanism 30 to drive the right rear wheel 12.

The left front wheel behind the right front wheel 13, is drivingly connected to the top feed roll 20 through a transmission system 32, including sprockets and chains, over-driven clutches, and an electromagentic feed clutch 47, in such a manner that the top feed roll 20 is driven in the same direction independently of the front wheels 13.

Referring now to the electrical circuit diagram in FIG. 4, a power supply circuit 35 is connected to any suitable source of electricity, not shown, through the power switch 36, which is also disclosed upon the control panel 37 mounted on the side of the frame 11, as disclosed in FIG. 1.

The supply circuit 35 comprises the primary circuit of transformer 38 which changes the voltage in secondary circuit 39. Connected in parallel to secondary circuit 39 is the edge control circuit 40 for energizing the edge control apparatus 18.

Automatic switch 42 is provided in secondary circuit 39 for supplying electricity to all of the other electrical circuits of the spreading machine 10, except the edge control circuit 40. Thus, as long as the power switch 36 is closed and automatic switch 42 is open, the edge control 18 will continuously operate to align the cloth web 17. Thus, when the cloth supply roll 15 is loaded and the web 17 is threaded to the spreader frame 21, or when the frame 11 is pushed for manual spreading, the web 17 is continuously and automatically aligned.

Connected in series with the secondary circuit 39 is the brake-clutch circuit 43 which feeds current to the DC. supply drive circuit 44 for the electromagnetic brake 45, and to the DC. supply drive circuit 46 for the electromagnetic clutch 47. The brake 45 and the clutch 47 are connected in parallel by brake circuit 51. The electromagnetic brake 45 is disclosed in FIG. 1 for engaging and disengaging the drive shaft 29, which in effect will brake or release the rear wheels 12 for moving the carriage frame 11. The electromagnetic clutch 47 couples the electric motor 28 to the left rear drive wheel in any convenient manner, not shown. The electromagnetic clutch 47 and the electromagnetic brake 45 are energized by the closing of drive switch 48. Thus, when it is desired to manually operate, that is manually move, the spreader frame 11, then the drive switch 48 is opened to disengage the clutch 47 from the motor 28 and to de-energize the brake 45 so that the frame 11 may free wheel". Electromagnetic brake 45 may also be de-energized by the opening of switch 49, normally closed, when the brake relay coil 50 is energized.

Connected in parallel to the brake clutch circuit 43 through the normally closed stop switch 53 is the speed circuit 54. The speed circuit 54 comprises a high-speed circuit 55 connected in parallel with the low-speed circuit 56. Mounted in parallel in high-speed circuit 55 are a pair of normally open, momentary, unidirectional, high-

speed switches

57 and 58. The highspeed switch 57 is shown in FlG. 2 mounted in the plunger box 60. Connected in series in the low-speed circuit 56 are a pair of normally closed, momentary, unidirectional, low-

speed switches

61 and 62, both of which are shown mounted in the low-speed switch box 63 on the side of the carrier frame 11. The front low-speed switch 62 is provided with a depending arm 64 which is adapted to engage and be actuated by the actuator ramp 65 as the carrier frame 1 1 moves from left to right in FIG. 1, that is, in a forward direction towards the catcher mechanism 24. However, when the frame 11 moves in its reverse direction away from the catcher frame 24, the arm 64 merely rides back over the actuator ramp 65 without energizing or de-energizing the switch 62. The switch 61 is provided with the depending arm 66 which operates in reverse upon a ramp similar to 65 at the opposite, that is, the far left, end of the table 14.

The high-speed circuit 55 includes a speed control relay coil 68, which is also connected in series with the low-speed circuit 56 through the holding relay switch 69, controlled by the coil 68. The speed selector switch 70 is also a relay switch controlled by the coil 68 to selectively connect either a low-speed potentiometer 71, or a high-speed potentiometer 72, to the motor speed control apparatus 73 of conventional design.

Thus, when either of the high-

speed switches

57 or 58 is momentarily closed, the coil 68 is energized to depress the

relay switches

69 and 70 causing the low-speed circuit 56 to act as a holding relay circuit and connecting the high-speed potentiometer 72 to motor speed control apparatus 73. However, when either of the low-

speed switches

61 or 62 is opened, the holding coil 68 is de-energized to open the holding relay 69 and connect the selector switch 70 with the low-speed potentiometer 71.

From this description of the speed circuits 55 and 56, it will be seen that when any of the switches, that is low-speed switch 62, low-speed switch 61, stop switch 53, automatic switch 42, or power switch 36 is opened, the holding coil 68 will be deenergized causing the selector switch 70 to disconnect the high-speed potentiometer 72 and connect the low-speed potentiometer 72 to the speed control apparatus 73, thereby changing the speed of the carriage frame 11 from high to low. The change from high speed to low speed will also be effected if there is any power failure or if the power supply circuit 35, secondary circuit 39, speed circuit 54, or low-speed circuit 56, is interrupted or broken in any manner. Thus, an electrical speed control has been designed for causing the machine to fail safe into low speeds for various changes in function of the electrical circuit.

Connected in series with the stop switch 53 is a starting circuit 75 including a manually operated, start switch 76. When the start switch 76 is depressed, the starting relay coil 77 is energized to close the holding relay switch 78 to maintain the starting circuit 75 energized, even when the manual starting switch 76 is released. A second relay switch 79 is connected in the motion circuit 80 to be moved to a closed position upon energization of the starting coil 77.

The motion circuit 80 is supplied with current through the motion supply circuit 81, which also furnishes current to the brake relay circuit 82 to energize the brake relay coil 50 and thereby release the brake 45. A motion switch 84 is adapted to open and close the motion circuit 80, and is in the form of a plunger located in the top of the remote control handle 85.

The handle 85 is adapted to be held in the operators hand, and is connected to the control panel 37 through an electrical cable 86, for remote control of the machine 10. As shown in FIG. 1, the operator's handle 85 is suspended in a bracket 87 mounted on the side of the carrier frame 11. While the handle 85 is mounted in the bracket 87, the motion switch plunger 84 is maintained depressed to close the motion circuit by a depressing lug 88. The handle may be removed from the bracket 87 so that the operator may start and stop the machine 10 from a remote position.

Also located within the handle 85, as indicated in FIG. 4, is the variable high-speed potentiometer 72 which is connected to the motor speed control apparatus 73 through a lead, not shown, within the cable 86 and through the selector switch 70. The wiper on the high-speed potentiometer 72 is connected to, or forms a part of, the plunger switch 84. Thus, as the plunger switch 84 is depressed, the motion circuit 80 is first closed to start the motor 28, and then the speed of the motor 28 is gradually increased with continued depression 'of the plunger switch 84, as long as the selector switch 70 is connected to the high-speed potentiometer.

When the remote control handle 85 is hanging in its bracket 87, the depressing lug 88, which is threaded for vertical movement, may be adjusted to maintain the plunger switch 84 depressed in any desired position to obtain motor speeds of various corresponding values, while the selector switch 70 is in high-speed position.

The cable 86 is preferably long enough so that the operator may stand in front of the machine to observe the spreading operation, and still control the starting, stopping and speed of the machine. The remote control handle 85 therefore provides a very versatile cloth spreading machine 10 in which the operator has full control over the motion and speed of the machine at all times while the machine is normally operating at high speed between the ramps 65. As soon as the machine is actuated into low speed by either ramp 65 opening its corresponding low-

speed switch

61 or 62, the operator can no longer control the speed of the machine, but can merely stop the machine, until the corresponding high-

speed switch

57 or 58 is closed.

By manipulating the plunger switch 84 while the selector switch 70 is in high speed, the operator may select any maximum speed he desires within the range of the high-speed potentiometer 72. The operator may slow down-the machine 10 at any time, between the ramps 65, to inspect the fabric for flaws, and may increase or decrease the speed of the machine 10, at will, for any purpose.

An auxiliary motion supply circuit 90 is connected in parallel with the motion supply circuit 81, and contains in series the normally closed, momentary, reversing

switches

91 and 92. One of these reversing switches 92 is disclosed in FIG. 2 in the plunger box 60. The other reversing switch 91 is located in a similar position in the catcher box 60 at the rear end of the carrier frame 11. The forward reversing switch 92, when actuated is adapted to move to its dashed-line position to close the forward directional circuit 93 which includes in series a forward relay coil 94. In a similar manner, when the rear reversing switch 91 is actuated, it moves to its dashed-line position to close the reverse directional circuit 95, which includes in series the reverse relay coil 96. Both of the directional circuits 93 and 95 may be provided with a manual directional switch 98, which is adapted to remain in the neutral position disclosed in FIG. 4, or be selectively turned to close either the forward directional circuit 93 or the reverse directional circuit 95, at the will of the operator.

The forward coil 94 and the reverse coil 96 are adapted, when alternately energized, to simultaneously move between forward and reverse positions, the motor directional relay switch 99 and the cloth feed directional relay switch 100. Both of these relay switches 99 and 100 are disclosed in their solidline positions for closing the respective

reverse circuits

101 and 103. The relay switches 99 and 100, when in their dashedline positions, will close their respective forward circuits 102 and 104. When the respective reverse and forward motor relay circuits 101 and 102 are respectively energized from motor directional circuit 135, they will illuminate their

respective pilot lights

105 and 106, as well as energize their respective forward and reverse motor relay coils 107 and 108. Energization of the reverse motor relay coil 107 simultaneously closes the reverse input relay switch 109 in the motor input circuit 110, the reverse fail-safe switch 111, and the reverse output relay switch 112 in the motor output circuit 113.

In a similar manner, when the forward motor relay coil 108 is energized, the input circuit 110 is closed by the forward input relay switch 114, the fail-safe switch 115 is closed, and the forward output relay switch 116 is closed to close the output circuit 113.

Motor input circuit 110 and motor output circuit 113 are connected to each other by the armature leads 119 and 123 adapted to be connected to opposite sides of the armature 120 through the armature relay switches 121 and 124 when closed in their dashed-line positions by the energization of the motor relay coil 122. When the motor relay coil 122 is de-energized, the relay switches 121 and 124 are returned to their solid-line positions which connect the armature 120 to the dynamic brake 125, and automatically disconnects the armature 120 from the armature leads 119 and 123. Thus, when the relay switches 121 and 124 are in their de-energized positions, the energy from the armature 120 is discharged through the dynamic brake resistor 125 in order to brake the motor 28. The input circuit 110 and the output circuit 113 are connected to the motor speed control apparatus 73, and to a DC source ofsupply.

The cloth feed reverse relay circuit 103 and forward relay circuit 104 are connected through the respective manual reverse feed switch 127 and forward feed switch 128 to the magnetic cloth feed clutch 130, which in turn is connected through feed circuit 129 to the DC. cloth feed supply 132.

Referring back to the low-speed circuit 56, the fail-

safe switches

111 and 115, which are selectively closed by the reverse and forward coils 107 and 108 in the motor directional circuitry, are connected in parallel to alternately close the low-speed circuit 56. The fail-

safe switches

111 and 115 are duplicated in FIG. 4 to more clearly disclose their actuation and their function by avoiding an unnecessarily complicated wiring diagram. Thus, every time either of the reversing

switches

91 or 92 is actuated, the low-speed circuit 56 is mo mentarily interrupted by the shifting of the open and closed positions of the fail-

safe switches

111 and 115, to release the holding relay 69 in the event it is being held in the high-speed position. In other words, the

switches

111 and 115 cause the circuit to fail safe into low speed upon every reversing movement of the carrier frame 11.

It will be noted that when the holding relay 69 of the lowspeed circuit 56 is in its normally de-energized position, it closes a time delay circuit 137.. The sequence of the time delay circuit 137 is such that after it is supplied with power through the relay switch 69, it will energize a relay coil 138 at the end of a predetermined period of time, for example, one second. Then the sequencing of the time delay circuit 137 will deenergize the coil 138 after a second pre-determined period, for example one-half second. While the time delay relay coil 138 is energized, it will close the relay switch 139 in the face circuit 140, and will simultaneously open the relay switch 141 in the motion circuit 80. After this brief period (one-half second) of energization of the relay coil 138, it becomes deenergized so that the relay switch 139 and the motion relay switch 141 resume their solid-line positions disclosed in FIG. 4.

However, if the face switch 142 in the face circuit 140 is manually closed, while the time delay relay switch 139 is closed, the face relay coil 143 is energized to close the face holding relay switch 144, and to open, and hold open, the motion supply circuit relay switch 145. The motion supply relay switch 145 will remain open until the manual overide switch 146 in the operators handle 85 is manually opened, to deenergize the holding coil 143.

The purpose of providing the time delay relay switch 141 is to open the motion circuit a brief enough period to dynamically brake the motor 28 from high speed to low speed. Because of the more rapid deceleration of the frame 11, the low-speed switch ramp 65 may be located closer to the catcher mechanism 24 so that the carrier frame 11 may travel a greater distance at high speed, and thereby improve production by reducing the spreading cycle time.

The manual face switch 142 is opened for face-to-face spreading, and is closed for either face-up or face-down spreading. When the face switch 142 is closed to hold open the motion supply circuit 81, then the sole source of power for the motion circuit 80 is through the auxiliary motion supply circuit 90. Accordingly, during face-up or face-down spreading, the motion circuit 80, as well as the brake circuit 82, is deenergized upon the actuation of either of the reversing

switches

91 or 92. When either switch 91 or 92 is actuated, the carrier frame 11 is immediately stopped because, not only is the motor 28 dynamically braked, but also the magnetic brake 45 is immediately energized to brake the drive shaft 29 and therefore the rear wheels 12. Whichever reversing

switch

91 or 92 is actuated, remains in its open position because the machine stops immediately in the actuated position of the reversing switch. In order to re-start the machine 10, the override switch 146 must be opened manually by the operator to close the relay switch and thereby supply energy through the motion supply circuit 81 to the motion circuit 80 and the brake circuit 82, by-passing the auxiliary motion supply circuit 90.

During face-to-face spreading the face switch 142 remains open so that the motion circuit 80 and brake circuit 82 receive a continuous supply of current through the closed motion supply circuit 81, regardless of the actuation of the reversing

switches

91 and 92.

Where a catcher mechanism 24 is used to cooperate with the spreader unit 21 in order to form a fold in the end of a layer of cloth, particularly in face-to-face spreading, the catcher bar 25, while engaging the depending web 17 and folding it over the tuck blades, not shown, creates an extra demand on the cloth feed, which, if not met, will produce undue tension on the cloth web 17. In order to supply this extra demand of cloth during the very brief period of folding the end ofthe layer 22, a cloth overfeed device 150 is mounted to control one end of the top roll. The cloth roll feed device 150 includes a gear or pinion 151 coupled to the cloth feed roll shaft 152 by an overriding clutch, not shown. A vertically reciprocable plunger rack 153 engages the gear 151 in such a manner that when it is thrust upward by the solenoid 154, the top roll 20 is fed forward at a higher rate than its normal feed rate.

As best disclosed in FIG. 3, the plunger rack 153 is pivotally attached by pin 155 to the armature of the solenoid 154, so that it may be manually pivoted rearwardly, as disclosed by the arrows, to dis-engage the gear 151 and to actuate, and thereby open, the switch 156. Opening the switch 156 will deenergize the magnetic feed clutch 130, when it is desired for any reason to manually dis-engage the cloth feed drive, such as when it is desired to manually turn the top roll 20. The solenoid 154 is energized by either one of the

overfeed switches

157 and 158. The overfeed switch 157 is located in the rear plunger box 60 while the other overfeed switch 158 is disclosed in FIG. 2 in the front plunger box 60.

With reference to FIG. 2, the front plunger box 60 includes the reversing switch 92 located at the rear of the box, and the overfeed switch 158 and the high-speed switch 57 located in the front of the box 60. Reciprocably mounted for longitudinal movement through the plunger box 60 are a pair of

plunger rods

160 and 161 which carry a plunger plate 162 adapted to engage and be depressed by the stop plate 163 fixed to the table 14 adjacent the catcher mechanism 24.

Plunger rods

160 and 161 carry actuator lugs or

cams

164 and 165 for selectively actuating the

switches

92, 158 and 57. Thus, as the carrier frame 11 moves forward in low speed to cooperate with the catcher mechanism 24, the plunger plate 162 engages the stop plate 163. The

plunger rods

160 and 161 are stopped while the plunger box 60 continues to ride along the rods causing one of the actuators 165 to actuate the overfeed switch 158, which opens the feed clutch circuit 129 and simultaneously energizes the overfeed solenoid 154, accelerating the top roll 20 to supply extra cloth to the spreader unit 21. The high-speed actuator 165 merely rides over the high-speed switch 57 without actuation. As the plunger box 60 approaches the plunger plate 162, the actuator 164' will actuate the reversing switch 92 causing the relay switches 99 and 100 to shift to their solid-line positions in FIG. 4, thereby reversing the motor circuit as well as the cloth feed circuit. The carrier frame 11 then begins to move rearward away from the catcher mechanism 24. Since the front wheels 13 reverse their rotation upon the table 14, the transmission 32 between the wheel 13 and the top feed roll 12 is also reversed, but the energization of the feed clutch 130 is also reversed to continue to drive the top feed roll 20 and the cloth web 17 forward.

As the frame 11 begins to move in reverse, the plunger box 60 also moves in reverse with the spring 166 urging the plunger plate 162 outwardly while it remains abutting the stop plate 163. As soon as the high-speed actuator 165 returns to the high-speed switch 57, it actuates the highspeed switch 57 to close it, closing the relay switches 69 and 70 to actuate the motor speed control apparatus 73 into high speed. Consequently, after the frame 11 has moved a very short distance rearwardly away from its forward limit of travel, it immediately resumes its high-speed movement toward the opposite end of the table 14.

It is, therefore, apparent that a very complete electrically driven and controlled cloth spreading machine has been developed which may be driven automatically, semi-automatically or even manually. Furthermore, the machine may be driven a maximum distance at high speed, and then decelerated by dynamic braking of the electric motor in a minimum of time and distance to attain a rather constant low speed immediately prior to reaching its reversing station.

The machine is designed so that it may be selectively employed for either face-to-face spreading or face-up or facedown spreading by manually opening or closing the face switch 142. When the face switch 142 is opened, and the motion switch 84 is maintained closed, the machine may continuously operate automatically for face-to-face spreading with the spreader unit 21 cooperating with the catcher mechanism 24 at one end and a similar catcher mechanism, not shown, at the opposite end of the table 14.

When the face switch 142 is closed, the machine 10 will automatically stop when either of the reversing

switches

91 or 92 is actuated by the plunger plate 162 engaging the stop plate 163. In this manner, the single layer of cloth which is spread face-up or face-down may be inspected, cut by any convenient cutting means, and then the manual override switch 146 opened to resume the movement of the frame 11 rearward in its non-spreading direction.

Furthermore, in face-to-face spreading both the forward and reverse feed switches 127 and 128 must be closed; whereas, in face-up or face-down spreading, only one of the feed switches 127 or 128 is closed.

The machine is provided with not only dynamic brake 125 for decelerating the motor 28 rapidly every time the machine changes from its high speed to its low speed, but is also provided with an electromagnetic brake 45 for braking the wheels 12 to an immediate stop, when the brake circuit 82 is de-energized.

One of the most important features of the invention is the ability of the machine 10 to fail safe in low speed for numerous changes in function of the machine, such as power failure, broken wires, and, most important, the automatic reduction of speed for every reversing motion of the machine. This is particularly important where, for example, if one of the low-

speed switch arms

64 or 65, for some reason, should not engage the ramp 65, or the ramp 65 is misplaced or removed. Thus, as the machine 10 moves into the catcher 25 at high speed, the actuation of either reversing

switch

91 or 92 will momentarily open both fail-

safe switches

111 and 115 to open the lowspeed circuit 56, causing selector switch 70 to return to its low-speed position.

The remote control handle 85 is also adapted to hang on the bracket 87 to automatically maintain the motion switch 84 closed for full automatic movement. However, when the operator removes the remote control handle 85 from the bracket 87, the motion control switch 84 must be manually depressed inorder to move the frame 11. If the operator for any reason is negligent, or has his attention distracted, or for any other reason, removes his finger from the motion switch 84, it will automatically open the motion circuit 80, de-energizing the motor relay coil 122 so that the armature is immediately disconnected from its power and discharges its energy through the dynamic brake resistor 125 causing the machine 10 to stop in a very short distance.

Another safety feature of the machine 10 is that both the start switch 76 and the motion switch 84 must be closed before the motor 28 will be energized. As an extra precaution, the stop switch 53 is provided for manually opening both the speed circuit 54 as well as the starting circuit 75, which in turn automatically opens motion circuit 80 to dynamically brake the frame 11 to a halt.

What is claimed is:

1. Fail-safe speed reducing means for a cloth spreading machine having a frame supported for longitudinal movement over a cloth laying surface between reversing stations, a spreader unit to spread cloth in layers, and means for supplying cloth to the spreader unit, comprising:

a. electrically energized motor drive means for moving said frame longitudinally of said surface,

b. electrical speed control means including selector switch means operable between a low position for energizing said drive means to move said frame at a low speed, and a high position for energizing said drive means to move said frame at a high speed substantially faster than said low speed,

c. a low-speed circuit including a normally closed, lowspeed switch,

d. low-speed actuating means to open said low-speed switch;

e. a high-speed circuit including a normally open, highspeed switch,

f. high-speed actuating means to close said high-speed switch,

g. a switch device in said low-speed circuit,

h. said switch device having a closed position operable to shift said selector switch means to said high position, and an open position operable to shift said selector switch means to its low position, said switch device being in said open position when said low-speed circuit is open,

i. said high-speed circuit being operatively connected to said switch device to bias said switch device to its closed position when said high-speed switch closes,

j. means for supplying power to said low-speed and highspeed circuits k. trigger means for operating said low-speed actuating means and said high-speed actuating means in accordance with a predetermined program.

2. The invention according to claim 1 further comprising a dynamic braking circuit connected to said motor drive means, dynamic braking switch means coupling said dynamic braking circuit to said switch device whereby when said switch device moves from its closed position to its open position, said dynamic braking switch means is actuated to energize said dynamic braking circuit and simultaneously de-energize said motor drive means.

3. The invention according to claim 2 further comprising time-delay means coupled to said dynamic braking switch means to limit the time said dynamic braking switch means is actuated.

by said high-speed actuating means.

6. The invention according to claim 1 in which said selector switch means comprises a selector relay switch, and said switch device comprises a relay coil adapted to control said selector relay switch.

7. The invention according to claim 6 in which said switch device comprises a holding relay switch in said low-speed cir cuit, said relay coil being in series with said high-speed circuit and also being adapted to control said holding relay switch.

Claims

1. Fail-safe speed reducing means for a cloth spreading machine having a frame suPported for longitudinal movement over a cloth laying surface between reversing stations, a spreader unit to spread cloth in layers, and means for supplying cloth to the spreader unit, comprising: a. electrically energized motor drive means for moving said frame longitudinally of said surface, b. electrical speed control means including selector switch means operable between a low position for energizing said drive means to move said frame at a low speed, and a high position for energizing said drive means to move said frame at a high speed substantially faster than said low speed, c. a low-speed circuit including a normally closed, low-speed switch, d. low-speed actuating means to open said low-speed switch, e. a high-speed circuit including a normally open, high-speed switch, f. high-speed actuating means to close said high-speed switch, g. a switch device in said low-speed circuit, h. said switch device having a closed position operable to shift said selector switch means to said high position, and an open position operable to shift said selector switch means to its low position, said switch device being in said open position when said low-speed circuit is open, i. said high-speed circuit being operatively connected to said switch device to bias said switch device to its closed position when said high-speed switch closes, j. means for supplying power to said low-speed and high-speed circuits k. trigger means for operating said low-speed actuating means and said high-speed actuating means in accordance with a predetermined program.

4. The invention according to claim 1 further comprising reversing control means for actuating said motor drive means to reverse the direction of motion of said frame at each reversing station, said reversing control means comprising a normally closed, fail-safe switch in said low-speed circuit, said reversing control means being operable to open said fail-safe switch each time the motion of said frame is reversed.

5. The invention according to claim 1 in which said low-speed switch is momentarily opened by said low-speed actuating means, and said high-speed switch is momentarily closed by said high-speed actuating means.

7. The invention according to claim 6 in which said switch device comprises a holding relay switch in said low-speed circuit, said relay coil being in series with said high-speed circuit and also being adapted to control said holding relay switch.