US2337143A - Safety control for machines having opening and closing movements - Google Patents

Description

Dec. 21, 1943. B, YANCHENKO 2,337,143

SAFETY CONTROL FOR MACHINES HAVING OPEI IING AND CLSING MOVEMENTS FiledMay 11, 1942 4 Sheets-Sheet l INVENTOR BASIL J. YANCHENKO ATTORNEYS DC. 21, 1943. YANCHENKO 2,337,143

SAFETY CONTROL FOR MACHINES HAVING OPENING AND CLOSING MOVEMENTS Filed May 11, 1942 4 Sheets-Shee t 2 i 35 N FIG. 2 I 32 28 33 31 I8 29 38 f )20 2s girl/ll 'INVENTOR BASIL J. YANQHENKO ame d/W 'TORNEYS Dec. 21, 1943. YANCHENKO 2,337,143

SAFETY CONTROL FOR NACHINES HAVING OPENING AND CLOSING MOVEMENTS Filed May ll, 1942 4- SheefiS-S'neet 3 i 2 l m, may a I I ZMVENTOR EAS H. J. YAf-ECHEMKO ATTO R N LYS B. J. YANCHENKO 2,337,143

SAFETY CONTROL FOR MACHINES HAVING OPENING AND CLOSING MOVEMENTS Filed May 11', 1942 4 Sheets-Sheet 4 F595 7 FIG. 4

5' 2; a I M N i I J a v INVENTOR BASIL J. YANCHENKC BY J @aM n/M ATTORNEYS Patented Dec. 21, 1943 SAFETY CONTROL FOR MACHINES HAVING OPENING AND CLOSING MOVEMENTS Basil J. Yanchenko, Syracuse, N. Y., assignor to The Prosperity Company, Inc., Syracuse, N. Y., a corporation of New York Application May 11, 1942, Serial No. 442,480

10 Claims.

, This invention relates to safety controls for machines including a head cooperating with a work support or anvil, as for instance a riveting machine, in which the riveting head or punch is actuated by a pressure-operated, or cylinder and piston, motor, and has for its object a safety control for a pedal operated machine, which includes a timing device for de-energizing the motor a predetermined time period, after it has actuated the head or punch, or for temporarily taking the control away from the pedal, so that pressure Will be relieved, regardless of whether the pedal is held depressed, and also by which repeated operations, upon one operation of the pedal, are prevented.

The invention further has for its object a safety control embodying the timing device and wherein a power operated guard controlled by the foot pedal moves in advance to the head or punch, and if the guard encounters no obstruction, the power is relayed or transferred to a device for opening a master control or master valve, permitting the motor of the machine to be energized, but if the guard encounters an obstruction, the power is prevented from being relayed to operating means for the master control or valve.

The invention further has for its object a safety control for small riveters, as so-called squeeze riveters, which is particularly simple, sure, accurate in operation, and highly eflicient in use.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a fragmentary side elevation, partly in section, of a squeezeriveter equipped with this invention or showing this invention apphed to a squeeze riveter.

Figure 2 is an enlarged sectional view of parts seen in Figure 1, the machine being shown in its open position.

Figure 3 is a view similar to Figure 2 showing the machine in operated position, or while operated.

Figure 4 is a fragmentary view of parts seen in Figure 2 showing the action of the guard and the control mechanism, when the guard encounters an obstruction, as the thumb of the operator.

Figure 5 is a fragmentary detail view of the timing device for timing the closing of the master valve or taking the control away from the pedal.

Figure 6 is an enlarged sectional view on line 66, Figure 4.

Figure 7 is a fragmentary detail view, showing a slightly modified form of guard used when a channel or cup shaped part is to be riveted t a base strip.

The construction of the squeeze riveter itself forms no part of this invention, and in so far as this invention is concerned, it may be of any suitable form, size and construction.

I designates the upper portion of the frame of the squeeze riveter, which carries the work support and the movable head or punch, this being supported on a suitable pedestal 2 rising from a base 3. 4 designates the work support or anvil, and 5 a movable head or punch suitably guided in a passage'formed in the head 6 of the motor for actuating the head or punch 5. In machines of this character, the head Or punch 5 is usually operated by a pneumatically operated motor, and hence, as here shown, the motor includes a cylinder I and a piston 8 movable therein. The motion of the piston is transferred to the head or punch 5 through suitable motion transmitting mechanism, not shown, including a part 9 coacting with the upper end of the head or punch 5. The punch 5 is actuated by the piston 8 against the action of a suitable returning spring Ill. The piston 8 is returned to its starting position, usually by ,a second piston I workin in a suitable cylinder I2 andhaving its rod I3 connected to the piston 8. The control of the air to and from the cylinder I is effected by a master control valve tobe hereinafter described.

The cylinder I2 is in open communication with the feed line at all times, but the piston II is of.

much smaller pressure area than the piston 8,.

so that when the master valve is opened, the piston 8 overcomes the piston II, and when the master valve is closed and the air is free to exhaust from the cylinder I, the piston II returns the piston 8 to starting position, and thereby permits the head or punch 5 to return to open position. The construction thus far described per se forms no part of this invention.

This invention relates to the control of the flow of power, and in this instance, a pressure fluid, to the motor for the head 5, means for automatically timing the de-energization of the motor a predetermined time, regardless of any operator J control, as a foot pedal, even though the foot pedal is held depressed, and also a power-operated guard, and means for relaying the power to means for operating the master valve, after the guard has been moved to safety position.

As the motive fluid is compressed air, and the motor a pneumatic motor, the master control is a valve. [4 designates the master control valve, this being shown as mounted upon or assembled with the cylinder 1. and having a movable member including a normally closed intake valve head I5 and a normally open exhaust valve head [6, these being connected together, so that they act as a unit, the intake end of the casing communicating with a suitable main feed or service line or pipe I? and the exhaust end of the casing communicating with the outer air through a passage I8. The valve communicates through a passage IS leading from the valve casing from between the valve heads into the upper end of the cylinder 1. The movable valve member consisting of heads [5, it are operated against a re turning spring 29. The master valve M is controlled in its movement to open the intake head [5 and close the exhaust head 16 by a pedal 2 through suitable mechanism.

In the illustrated embodiment of the invention, the pedal operates. a control valve 22 which controls the flow of air to a pressure-operated device 23, the movable member of which is a plunger 24 acting through a motion transmitting memher, as a slide 25, on the unit or one movable member of. the master valve. The pressure-operated device is here shown as a diaphragm chamber having a diaphragm 26 therein thrusting againsta head on. the plunger 24. The slide 25, against which the plunger 24 acts, is slidable in the valve casing l4 against the action of a returning spring 2], and embodies a thrust member normally thrusting-against the stem 28* on the movable member of: the master valve and being shiftable by a timer device out of its normal position, to permit the intake head 15 and the master valve to close and the exhaust valve head it to open a predetermined. time after the master valve has been: opened, eventhough the pedal 2 l is held depressed and the diaphragm chamber held under pressure.

This timer means consists of a cylinder 28 mounted on, or assembled as, a unit with, the master unit l4, and having a. piston 29 therein, thrusting against the thrust member 30 previously referred to, carried by and. movable relatively to the motion transmitting member or slide 25, it-being normally in position to transmit motionto operate the master valve and shiftable into position to permit the master valve to shift to normal, position, wherein. the intake is closed and the exhaust open. The thrust. member is here. shown as shiftable diametrically through the slide. 2.5. and normally thrusting against the stem, 28 of the movable member of the master valve. The thrust member 30 has a notch 3| therein arranged to be brought into alinement with the stem 23* to permit the intake valve head IE to close and the exhaust valve head to open. The shifting of the thrust member 30 is effected by the piston 29 in the timer cylinder 28. The timer cylinder 28' is connected on the pressure side of the piston 29 to the casing of the valve 14 through a restricted port or conduit 32 of such size as to require a definite time period to build up pressure in the cylinder 28 sufiiciently to actuate the piston 29 to shift the thrust member 30 against the action of a returning spring 33. The spring 33 acts on the piston 29. Also, a returning spring 34 acts on the member 39. The spring 33 is shown as interposed between an annular shoulder at the inner end of an adjusting screw 35 threading into the head of the cylinder 28, and against an internal annular shoulder 36 on the piston 29. The piston 29 is here shown as cup-shaped and the screw extends into the cup-shaped piston. The returning spring 34 for the latch 30 is located in the bottom of the transverse passage in which the thrust member 30 slides, and the spring is interposed between the lower end of the thrust member 33 and the bottom of the passage.

When the master valve is operated by the diaphragm chamber 26 in the chamber 23, this occurring upon the operation of the foot pedal 21, the intake Valve head I5 is opened and the eX- haust valve head It closed, and the parts assume the position shown in Figure 3, permitting air to flow from the feed line I! through the master valve and the passage l9 thereof into the upper end of the cylinder l, actuating the piston therein, and moving the head or punch 5 downward into the position shown in Figure 3. During this operation, the slide 25 is actuated by the plunger 24 from the position shown in Figure '2 to that shown in Figure 3, carrying the thrust member 30' therewith. The notch 3| is out of alinement with the stem 28 of the movable member of the master valve during this operation. When the master valve is thus operated, pressure builds up over a predetermined time period in the timer cylinder 28 through the restricted or small pipe 32, overcomes the resistance of the spring 33, acting on the timer piston 29 and the spring 34 acting on the thrust member 33. When the pressure builds up sufficiently to overcome these springs, the thrust member is shifted from the position shown in Figures 2 and 3 to that shown in Figure 5, bringing the notch 3| into registerwith the steam 28 of the movable member of the master valve. This permits the spring 20 to close the intake valve head I5- and open the exhaust valve head [6 of the master valve, so that air exhausts from the cylinder 1 and the piston 8 is drawn upwardly by the air pressure in the cylinder l2 against the lower side of the piston II. The cylinder I2 is in open communication with the main feed line through pipes 37 and 38. The timing is such that the head or punch 5 is moved into engagement with the end of the rivet, and then a squeezing pressure applied and held long enough to permit the rivet to set.

The control of the flow of air to the pressureoperated means or diaphragm chamber 23 and the operation of the guard will now be described. 46 designates a. guard in the form of a ringaround the path of the head or punch 5, this guard being power-operated, controlled by the pedal 2|, and movable in advance of the head 5 from the position shown in Figures 1 and 2, to that shown in Figure 3, and the movement of the guard into position shown in Figure 3 controls the flow of motive fluid to the pressure-operated means or diaphragm chamber 23 for the master valve M. The guard 45! is here illustrated as actuated by a. piston i l movable in a cylinder 45, which, for the sake of convenience, may be called a relay cylinder. The piston 44 has a rod 46 to which is coupled a stem d1 carr ing an arm or bracket 48 rigid with the guard ring Ml. The piston 44 is double acting or has upper and lower pressure faces d9, 50, the upper pressing face "39 being of greater pressure area than the lower pressing face 5i), due to the fact that the piston rod it reduces the pressure area of the pressure face 50. The upper end of the cylinder 45 is connected in the feed line through a conduit in which is connected the pedal operated control valve 22, this being located within the pedestal 2, the pedal 2| being also pivoted to the pedestal 2. The valve 22 is of the self-returnable combined intake and exhaust type and embodies a normally closed intake valve head 52 and a normally open exhaust valve head 53, these being connected together, so that they act as a unit, the unit being acted upon by a returning spring 54. The pedal 2|, through an arm 55, transfers its movement to the valve unit through a plunger 53. The operating movement of the pedal is against a returning spring 58. The intake end of the valve casing of the valve 22 is connected in a main air supply through a pipe 59. When the pedal 2| is depressed, the intake valve head 52 is opened and the exhaust valve head 53 closed, permitting air to pass from the main line 59 through the valve casing, conduit 5| to the upper end of the relay cylinder 45 and actuate the piston 44 against the opposing air pressures from the main line through pipe 33, thus lowering the guard 40 into the position shown in Figure 3, unless the guard should be obstructed, as shown in Figure 4.

Assuming that the guard is not obstructed, then the piston 43 can travel its full movement, and at the end thereof, uncovers a port 66] in the relay cylinder 45, which is connected by a conduit iii to the pressure side of the diaphragm chamber 23. If, however, the guard is obstructed, as shown in Figure 4, the piston 44 does not travel far enough to uncover the port 60, and hence the pressure-operated means or diaphragm chamber 23 is not energized, and the master valve remains closed. and hence the punch 5 does not operate.

In order to prevent building up of pressure in the cylinder 45 on the pressure face 49 of the piston sufficiently to actuate the piston 44 to uncover the port 60, when the guard 40 is obstructed in its movement, an exhaust port 64 is provided in the side of the cylinder 45 and located between the pressure faces of the piston at all times to permit the exhaust of any air that might pass the end of the piston provided with the pressure face 49, This exhaust port 64 also permits the exhaust of any air passing the lower pressure face 53 of the p ston 44. To effect the passage of air that might work past the piston heads or faces, the piston 44 is formed with a lengthwise groove 62 into which the port 53 opens and with a circumferential groove 63.

The stem t! for supporting the guard 43 is adjustably mounted in the rod 46 of the piston, and as here shown, the piston is formed with an axial passage extending inwardly from its lower end for receiving the stem 41. The end of the piston rod is split or formed with four lengthwise slots and is also threaded for receiving a nut 65. The nut and the threaded end of the piston rod 4| form a compression coupling. The stem 4'! is non-circular or square and the stem 26 formed with four slots. The corners of the square are seated in the slots, and when the nut 65 is tightened, the square stem 4'! is tightly clamped against rotation and axial displacement. The piston 44 is also held from rotation in its cylinder 45 by a screw or key 63 extending through the cylinder wall into a lengthwise slot 61 in the piston. ihe stem 43 of the ring-shaped guard 40 is also adjustable lengthwise to accurately locate the guard or guard ring 40, and as here shown, the stem 48 extends through a collar 68 in the lower end of the stem 4! and is held in its adjusted position by a clamping screw 69. The cylinder may also be mounted for ver-, tical adjustment on the main cylinder 1, it being shown as carried by a base plate 10 having a vertical slot or slots H therein for receiving screws 12 threading into the cylinder I.

In Figure '7, the guard is shown as in the form of a sleeve 40 and as connected by an angular arm to the piston rod 46 This sleeve type of guard 40 is used when a channel or cup shaped part as C is to be riveted to a base strip D through the bottom of the cup or channel shaped part C and is of such diameter as to enter the channel through the open side thereof. If the operator should take hold of the work with the thumb or a finger on the edge of the part C, the guard 40* will be obstructed in its downward movement and held from movement into the channel, and hence the punch 5 will not be actuated.

The general operation is as follows:

The operator places two strips of work to be riveted together with a rivet through alined holes therein on the anvil 4 holding his fingers out of the path of the guard 40. He then depresses the pedal 2|, operating the pedal controlled valve 22 to permit the flow of air to the upper end of the cylinder 45, actuating the piston 44 therein, to move the guard from the position shown in Figures l and 2 into the position shown in Figure 3, this movement uncovering the port 6!] in the cylinder 45, permitting air under pressure to flow through the pipe 6| to the pressure side of the diaphragm chamber 23, actuating the diaphragm 26 therein and the plunger 24, to operate the movable member of the master valve from the position shown in Figure 2 to that shown in Figure 3, thus permitting air to enter the cylinder 1 of the main motor and actuate the punch or head 5. During this operation, the air pressure in the timer cylinder 28 is being built up and when it is built up to a predetermined extent, the piston 29 of the timer cylinder actuates the latch from the position shown in Figure 2 to that shown in Figure 5, permitting the movable member of the master valve to return to its normal position (Figure 2), and hence permitting the air to exhaust from the cylinder 1 and the punch or head 5 to open. The piston 8 in the cylinder 1 is moved upwardly or returned to its starting position by the pressure in the cylinder I 2 against the piston ll. Phe operation of the timer cylinder and pistons 28 and 29 takes the control away from the pedal 2| and the control valve 22, so

that the pedal must be released before another operation can take place.

If, however, the operator so holds the work that the guard encounters a finger or portion of his hand, as seen in Figure 4, the piston 44 in the relay cylinder 45 can not travel far enough to uncover the port 69, and hence the diaphragm chamber 23 will not be energized and the master valve will not be operated.

A guard operated by a cylinder and piston,- which also operates to relay the flow of power to some other device to be operated, per se, forms no part of this invention, but constitutes the subject matter of my pending application, Serial Number 433,366, filed March 4, 1942.

What I claim is:

l. A safety control for machines which include a head movable toward and from a cooperating work support, and a motor for actuating and applying pressure to the head, the safety control.

including a power line, a master control element therein for controlling the flow of power to the motor and normally arranged to cut off the flow of power to the motor, a pedal controlled means for operating the master control element, and a timing device controlled by the master control element and operable to effect the return of the master control element to its normal position independently of the pedal controlled means, after the pedal has been held operated a predetermined time.

2. A safety control for machines which include a head movable toward and from a cooperating work support and a pressure-operated motor for actuating and applying pressure to the head, the safety control including a conduit line for a pressure fluid, a combined intake and exhaust self-returning master valve therein normally arranged with its intake closed and its exhaust open, a pedal controlled means for operating the master valve to open its intake and close its exhaust, and a pressure-operated timing device controlled by the master valve for effecting the return of the master valve to its normal position independently of the pedal operated means after the pedal has been held operated a predetermined time.

3. A safety control for machines which include a head movable toward and from a cooperating work support, and a pressure-operated motor for actuating and applying pressure to the head, the safety control including a conduit line for a pressure fluid, a combined intake and exhaust selfret'urning master valve therein normally arranged with the intake closed and the exhaust open, a pedal controlled means for operating the master valve to open its intake and close its exhaust, and a timing device controlled by the master valve for effecting the return of the master valve to its normal position independently of the pedal operated means, after the pedal has been held operated a predetermined time.

4. A safety control for machines which include a head movable toward and from a cooperating work support and a pressure-operated motor for actuating and applying pressure to the head, a safety control including a feed line for a pressure fluid, a combined intake and exhaust selfreturning master valve therein normally arranged with its intake closed and exhaust open, pressure-operated means, and a feed line therefor operating, when energized, to open the intake and close the exhaust of the master valve, a pedal operated self-returning intake and exhaust control valve in the feed line, a cylinder connected in the feed line controlled by the pedal operated valve, a piston therein, a guard operated by the piston in advance of the head, and a conduit connecting the cylinder and the pressure-operated motor through a port located to be passed by the piston, when the piston has traveled a predetermined distance.

5. A safety control for machines which include a head movable toward and from a cooperating work support and a pressure-operated motor for actuating and applying pressure to the head, a safety control including a feed line for a pressure fluid, a combined intake and exhaust selfreturning master valve therein normally arranged with its intake closed and exhaust open, pressure-operated means, and a feed line therefor operating, when energized, to open the intake and close the exhaust of the master valve, a pedal operated self-returning combined intake and exhaust control valve in the feed line, a cylinder connected in the feed line controlled by the pedal operated valve, a piston therein, a guard operated by the piston in advance of the head, a conduit connecting the cylinder and the pressure-operated device through a port located to be passed by the piston when the piston has traveled a predetermined distance and hence moved the guard a predetermined distance, and a pressure-operated timer device controlled by the master valve and operable to effect the return of the master valve to its normal position independently of the pedal operated valve and the pressure-operated means for master valve, after the pedal has been held operated a predetermined time.

6. A safety control for machines which include a head movable toward and from a cooperating work support and a pressure-operated motor for actuating and applying pressure to the head, a safety control including a feed line for a pressure fluid, a combined intake and exhaust selfreturning master valve therein normally arranged with its intake closed and exhaust open pressure-operated means, and a feed line therefor operating, when energized, to open the intake and close the exhaust of the master valve, a pedal operated self-returning combined intake and exhaust control valve in the feed line, a cylinder and a piston therein, a guard operated by the piston in advance of the head, conduits for pressure fluid connecting the cylinder in the feed line at opposite ends of the cylinder, the pressure faces of the pistons being of different pressure areas and the conduit connected to the end of the cylinder in which the piston face of less area is presented being in open communication with the feed line, the other end of the cylinder being connected in the feed line controlled by the pedal operated valve, and a conduit connecting the cylinder and the pressure-operated device through a port located to be uncovered by the piston, when the piston has traveled a predetermined distance from starting position.

7. A safety control for machines which include a head movable toward and from a cooperating Work support, and a pressure-operated motor for actuating and applying pressure to the head, a safety control including a feed line for a pressure fluid, a combined intake and exhaust selfreturning master valve therein normally arranged with its intake closed and exhaust open, pressure-operated means, and a feed line therefor operating, when energized, to open the intake and close the exhaust of the master valve, a pedal operated self-returning combined intake and exhaust control valve in the feed line, a cylinder and a piston therein, a guard operated by the piston in advance of the head, conduits for pressure fluid connecting the cylinder in the feed line at opposite ends of the cylinder, the pressure faces of the pistons being of different pressure areas and the conduit connected to the end of the cylinder in which the piston face of less area is presented being in open communication with the feed line, the other end of the cylinder being connected in the feed line controlled by the pedal operated valve, and a conduit connecting the cylinder and the pressureoperated device through a port located to be uncovered by the piston, when the piston has traveled a predetermined distance from starting position, said cylinder having an exhaust port located to exhaust to the outer air any pressure fluid passing the pressure faces of the piston.

8. A safety control for machines which inelude a head movable toward and from a cooperating work support, and a motor for actuating and applying pressure to the head, the safety control including a power line, a master control element therein for controlling the flow of power to the motor and normally arranged to cut oil. the flow of power to the motor, pedal controlled means for operating the master control element including a movable motion transmitting part, a shiftable thrust member carried thereby and normally arranged to transmit motion to the master control element and shiftable relatively to the motion transmitting part to permit the master control element to return to starting position. independently of the pedal operated control means, and a timing device controlled by the master control element and operable to shift the thrust member out of thrusting position to effect the return of the master control element to its normal position independently of the pedal controlled means after the pedal has been operated a predetermined time.

9. A safety control for machines which include a head movable toward and from a cooperating Work support and a pressure-operated motor for actuating and applying pressure to the head, the safety control including a conduit line for a pressure fluid, a combined intake and exhaust selfreturning master valve therein, normally arranged with its intake closed and its exhaust open, pedal controlled means for operating the master valve to open its intake and close its exhaust including a slide, a thrust member carried by the slide and shiftable relatively thereto and normally arranged to transmit motion to the master valve to operate it and shiftabl into a position to permit the master valve to return to its starting position, and a pressure-operated timing device controlled by the master valve for shifting the thrust member independently of the slide into position to permit the return of the master control valve to normal position.

10. A safety control for machines which include a head movable toward and from a cooperating work support and a motor for actuating and applying pressure to the head, the safety control including a power line, a master control element therein for controlling the flow of power to the motor and normally arranged to cut oil the flow of power to the motor, a self-returnable pedal controlled means for operating the master control element from normal position, a second power operated motor connected in the power line including a movable member, the master control element also controlling the flow of power to said second motor, a guard operated by the said movable member in advance of the head, and connecting means between the second motor and the first for controlling the flow of power to the first motor after said movable member and the guard actuated thereby has traveled a predetermined distance.

BASIL J. YANCI-IENKO.

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