US2215795A - Control for pressing machines - Google Patents

Description

Sept. 24, 1940. Q H PEARSON ET AL 2,215,795

CONTROL FOR PRESSING MACHINES I Filed July 20. 1958 4 Sheets-ShOOt 1 5. earson Sept. 24, 1940- o. H. PEARSON ET AL 2,215,795

CONTROL FOR PRESSING MACHINES Filed July 20, 1938 4 Sheets-Sheet 2 W n n m w w 3 r r a a e P w E 0.4 1 M I 9 fl 6 8 a 3 m. 96 D 2 8 3 5 3 3 j 8 7. 00 I 0 08 I m 111 8 7 o D o M 5m" o 7 r m 4 \-l|. I M 7 A 3 I. 6 -H 2E r////////////////////////Jx//// M////Mw ///////////////////4 =z 7/4 H I 8 7 MW w 6 i? M Sept. 24, 1940. o. H. PEARSON ET AL v CONTROL FOR PRESSING MACHINES Filed Ju1y 20, 1938 4 Sheets-Sheet 3 W r o 0- H. Pea/"5 H and E, Pea/Son Patented Sept. 24, 1940 UNITED STATES PATENT OFFICE CONTROL FOR PRE SSING MACHINES Otto H. Pearson, St. Joseph, Mich, and Ed Pearson, Salt Lake City, Utah, assignors, by mesnc assignments, to Nicholas L. Strike, Salt Lake City, Utah Application July 20, 1938, Serial No. 220,250 7 Claims. (01. 192-431) Our invention relates to pressing machines, and more particularly to two-handcontrolpressing machines. A

An important object of the invention is the provision in pneumatic means for operating such a machine, of a pilot valve, operable by relatively slight manual power, to actuate said pneumatic means and of pneumatic means to take up the wear of said valve.

In a machine of the character mentioned having three-position manuals for actuating the pilot valve, an object of the present invention is the elimination of spring means that moves the manuals from an intermediate to an inoperative position,-and the elimination of spring means to maintain the manuals in a full operative position.

A still further object is to provide pneumatic means to withdraw the barrier from between the toggles of the manuals and flexible means employed to take up wear inthe pilot valve.

In the drawings like reference characters designate similar parts in the several views.

Figure 1 is a side elevation of an embodiment of my invention.

Figure 2 is an enlarged section taken on line 2-2 of Figure 1.

Figure 3 is a reduced elevation looking in the direction of arrow 3-3 of Figure 2.

Figure 4 is a reduced plan view similar to Figure 2, but showing the full operative position of the manuals.

Figure 5 is a view of the pilot valve stem removed from the valve casing.

Figure 6 isfla broken enlarged section of the pneumatic driving cylinder for the press.

Figure '7 is a section through valve means for controlling the mechanism of the machine.

Figure 8 is a side elevation of a modified embodiment of my invention showing fluid means for controlling the barrier.

Figure 9 is an enlarged view of the head and finger for actuating the pilot valve showing resilient means for taking up' wear of the valve.

Figure 10 is a modified manner of taking up wear of the valve and seat by using a diaphragm under air pressure.

Figure 11 is a sectional view of the valve casing enlarged to show the interior of the valve used to operate the cylinder for actuating the barrier shown in Figure 7.

Figure 12 is a sectional view of a modified form of the head and finger for actuatingthe valve with the air chamber shown in whicha rubber tube is used to actuate the take-up finger to take up wear of the valve and seat.

Figure 13 is a view showing the use of this chamber mounted to actuate the main valve.

Figure 14 is a view showing the means for providing fluid to the type of chamber shown in Figure 12 actuated by a separate control valve such as shown in Figure 8 for actuating the finger.

Referring more in detail to the drawings, the reference number In generally designates the frame of the present machine, which supports a relatively stationary buck I2 and a pivotally mounted head l3. An arm M, which supports the head 13, is pivotally mounted on the frame at la. The, arm i4 is inturn pivotally connected with a link I6.

The link It, together with a therewith pivotally connected link ll, form a toggle generally designated Hi. The lower end of the link I! has a pivotal connection with a piston rod I9. A roller bearing 20, on the knuckle formed by the links ll and piston I9, rides on a cam 2| having an upwardly inclined face 22 and a concave top face 23. A spring BI may be coiled about the piston rod l9,.to cushion inward movement of the rod l9 into its cylinder hereinafter described.

One end of an oscillating tie bar 25 is pivotally mounted on a spindle 26 on theframe. The other end is connected with an offset stub shaft 24 at the elbow of the toggle l8;

A cylinder 21 has a ball and socket connection 28 with the frame of the machine, to permit oscillation of the cylinder. A piston 29 in the cylinder is mounted on the piston rod l 9.

Heavy coil springs 30 and 3| tend to move the head l3 to the open position shown in Figure 1. The link It carries an ear 32 "for reciprocating movement of a rod 33. A stop 34 on the rod 33 provides an abutment opposed to the ear 32, between which a spring 35, coiled about the rod 33, is disposed. An auxiliary spring 36 connecting with the frame and with the stop 34, may also be used. The springs 35 and 36 tend to move the rod toward the front of the machine.

Another stop 37 is disposed on the rod 33 on the otherside of the ear 32 from the stop 34. The stop 31 may be in the form of a nut on a threaded portion of the rod 33, to permit adjustments of the stop 31. By this arrangement, movement of the car 32 in one direction compresses the spring 35, tending to move the rod 33 forward, and movement of the ear 32 in the opposite direction causes it to strike the stop 37, effecting rearward movement of the rod.

A pipe 38 supplies air pressure, or other pressure fluid, to the machine. A manual valve 39 controls the flow therethrough. A branch 49 of the pipe 38 leads to a valve casing 4|, hereinafter more fully described. The pipe 38 connects with a valve housing 42.

The housing has chambers 43 and 44 connecting by means of a passage 45. A ball valve 46 in one position closes the passage 45. A coiled spring 4'! tends to move the ball'valve 46 to said passage closing position. To aid in assembling, the chamber 43 is closed by a screw plug 48. A pipe 49 connects the chamber 44 with a passage in head 5| of the cylinder 21. The passage 50 directs pressure fluid into the cylinder against the face of the piston 29, to urge the piston to the right in Figure '7.

An exhaust 52 connects with a chamber 53 in the valve housing 42. The chambers 44 and 53 connect by means of a passage 54, the walls of which passage provide a valve seat.

A valve 55, having a relatively slender pin 56 integral therewith, is disposed to reciprocate in the housing 42. The valve 55 when depressed engages the seat in the passage 54. When so depressed, the pin 56 pushes the ball valve 46 from its passage closing position, against the action of the coiled spring 41. Thus in said depressed position, the valve 55 closes the passage 54 and opens the passage 45, permitting fluid pressure to flow from the pipe 38, through the chamber 43, through the passage 45 through the chamber 44, and through the pipe 49 to the cylinder 21, to actuate the piston 29.

When the valve is released from said depressed position, the coiled spring 41 seats the ball valve 46 and through the intermediary of the pin 56 causes the valve 55 to move from its seat. In this position of the two valves, the flow of pressure fluid from the source to the cylinder is stopped, but since the chambers 44 and 53 are now connected, pressure fluid ahead of the piston 29 may pass through chamber 44, through passage 54, through chamber 53 and out at the exhaust 52.

A shell 51 has bolted between the complementary halves thereof, a diaphragm 58. A pin 59 fastened to the diaphragm reciprocates therewith. At the opposite side of the diaphragm from the pin 59, the shell 51 receives pressure fluid from the pipe 60. It will be noted that the pin 59 is arranged to depress or actuate the valves 55 and 46 against the action of the spring 41.

The mechanism is actuated by a pair of spaced manuals 62 and 63. It is to be understood that the manuals are so spaced that they cannot be operated by a single hand, but require both hands of the operator to operate. This arrangement prevents the operator from getting his or her hands caught between the descending head l3 and the buck l2, which would injure and burn the operators hands.

A table 64 is shown under the buck, and a flange 65 depends from the table. Openings 66 and 61 are arranged in the flange 65 to reach the ends only of the manuals 62 and 63 respectively.

The manuals 82 and 63 are pivoted at 68 and 69, which pivots are mounted upon a platform beneath the table 64. A strap ties the pivots 68 and 69 together. Mounted rigidly on the manuals 62 and 63 and forming bell cranks therewith are arms 12 and 13 respectively. Stops I4 and 75 limit outward movement of the arms 12 and 73. The bolts I90 rigidly fasten the arms 12, 13 to the manuals 62 and 63 respectively. The bolt |D9 are not pivots.

A whippletree is fastened at its ends to the arms 12 and 13, by means of links 16 and TI respectively. The whippletree adjacent its midpoint, carries a head 78 which is pivotally connected to the whippletree. The head 78 has a cylindrical recess for an air cylinder 19.

A finger 80 has a piston head 8| in the cylinder chamber 19 of the head 18. The head member 18 itself limits the outward movement of the finger head 8|, and the inward movement of the finger is limited by the air or fluid in the cylinder 19.

A pilot valve 82 is mounted in a tubular sleeve 82a and the stem is engaged by the end of the stem 80 which valve engages in the seat in the end of the exhaust chamber 89. The nut 84 is screwed onto the stem 82a to lock the valve casing 4| and component parts to the bracket 12a supporting it from the platform H1. The platform 10 is made of either solid or flexible material, that shown being flexible spring steel so that if desired the resilient means may be utilized in the platform 19.

The nose of the valve 82 is elongated as shown at 85, and engages a ball valve 86. The air pressure in the chamber 9| behind the ball valve 86 urges same against its seat in the casing 4|. When the valve 82 is moved inwardly relative to the casing 4|, the'ball valve 86 is moved from its seat against the air pressure in the chamber 9|.

The valve casing 4| has a chamber 88 that is provided with exhausts 89. The pipe 69 connects with a chamber 98 in the casing 4|. The pipe 40 connects with a chamber 9| also in the casing 4 A pipe 92 is connected to a T-coupling and in time to a pipe 9211 which is then connected to the head l8 into the cylinder 19 to provide air pressure to take up wear of the valve 82. The other connections of the T are either closed or may be connected with other machines if tandem connections of machines is desired.

The nose 85 of the valve 82 fits loosely in the casing whereby fluid pressure may pass around same at all times. The chamber 68 and 99 and chambers 90 and 9| are connected by the passages in which the nose 85 loosely fits. A screw plug 93 closes the end of the casing 4| in the end of the chamber 9 When the air pressure in the chamber 9| is seating the ball valve 86 upon its seat (which is its normal position When the manuals are in the full line positions, shown in Figure 2,) the flow of pressure fluid from the source is stopped. Moreover, in this position the exhausts 89 are connected with the diaphragm shell 51, whereby the diaphragm may be moved by it spring 94 to the position shown in Figure 7, releasing the valve 55.

When the valve 82 is moved inwardly r lative to the casing 4|, the taper of the valve 8 seats and thus seals the passage between the chambers 88 and 90, thereby shutting off the exhausts. At the same time the ball valve 86 is unseated, connecting the chambers 98 and 9| and thereby permitting fluid pressure to flow from the pipe 48 to the pipe 60, thus actuating the diaphragm 58, which in turn operates the main supply valve 46. It will thus be seen that the valve 86 acts as a pilot valve, requiring only relatively slight pressure to operate the main valve 46 of the machine.

To temporarily limit movement of thearms 12 and I3 toward each other, a barrier 35 is pro vided. It is in the shape of a bell crank 96 pivoted at 97. end of the bell crank 93 to move the barrier 35 to and from a position between the arms I2 and "3. The barrier is beveled to force the arms 12 and I3 apart (from the position shown in Figure 4) when the barrier is moved between them. The arms l2 and I3 have a limited movement between the stops l4 and I and the barrier.

To initiate the operation of the present invention, both manuals 62, 63 must be moved from the full line to the broken line positions: shown in Figure 2. If only one manual is so moved, the whippletree I5 is turned upon the head it without moving said head appreciably.

When both manuals are moved .to the broken line positions, the head I8 is advanced to the right in Figure 2. This movement causes. the finger 00 to actuate the valve 02, which opens the pilot valve 86 in the manner described hereinbefore. The pressure fluid then actuates the diaphragm, which opens the mainvalve 46 as explained herebefore. Fluid pressure is thereby admitted to the cylinder 21', thus driving the piston 29.

The force against the piston moves the roller bearing up the inclined face 22 and then around the concave face 23. This movement causes the closing of the head I3 down upon the buck I2, as shown in broken lines in Figure 1, against the action of the springs 30, 3I.

During the foregoing operation, the arms I2, i3, may be against the sides of the barrier 05. If, prior to the time the head I3 engages the buck I2, the operator releases either hand, the whippletree is turned, or if both hands are released, the force upon the whippletree is released. In either event, there is nothing to maintain the pilot valve 86 01? its seat. When said valve is seated, the flow of fluid pressure is checked, releasing the main valve 46 and permitting same to be seated, which checks the pressure flow to the cylinder 21. Since the cylinder is then connected with the exhaust 52, the large coil springs 30, 3! may and do return the head to the open, full line position shown in Figure 1 By the time the head I3 engages or substantiallyengages the buck I2, the ear 32 has engaged the nut 31, thus drawing the rod 33, which withdraws the barrier from between the arms 12, It. The operator may then move the manuals to the locked position shown in Figure 4. The locked position is the'over-center or past center position of the arms 12, I3 and the links I6, H, which armsand links respectively form opposed toggles. In this position, the operator may remove his hands from both manuals and the head I3 will remain in pressing engagement with the buck I2.

To raise the head l3, all that is necessary is to release either manual or both manuals. The manuals float in the inoperative or rest position designated by the full lines in Figure 2. This machine is marked by the absence of spring means to maintain the manuals in the full operative position (Figure 4), and by the absence of spring means that moves the manuals from the intermediate (broken line position in Figure 2) to the inoperative position.

The air pressure in the chamber is only to com pensate for wear of the valves 82 and 86 and their seats and is not adapted to perform the function mentioned earlier in this paragraph.

Upon release of either manual or both manuals, the fluid pressure is out 01f, the pressure in The rod 33 connects with the lower a the cylinderis exhausted, allowing the springs 3 I, 32, to raise the pressing head I3. At the same time the ear 32 moves away from the stop 31, thus releasing the rod 33 and allowing the springs 35, 36 to move the barrier up between the arms I2, "I3.

Constant pressure is maintained behind the piston 8| by the pressure in the line 40 passing through the line 92a thus the piston is main tained in its full stroke position and the only movement ever permitted is when the whippletree has been moved to the full operating position, the air in the cylinder and partially in the line will then be compressed sufficient to take up wear in the valve 82.

In Figure 8 of the drawings the valve mecha nism shown in Figures 1 and 7 is eliminated and the manuals control the valve 86 which controls the air flow through the line IOI to the cylinder 21 making a direct air control and thus simplify- 20 .a valve I04 in a valve casing mounted to the frame I0 and the valve is controlled by an adjustable stem I05. This stem is controlled and actuated by a-boss I 06 on the side of the toggle member I6 thus when the toggle has reached a near vertical position and the head I3 has been brought down to the bed member I2 or near thereto the stem N15 is engaged with the boss Hit and the valve I04 is operated which causes air from the line I01 to flow through the valve chamber and the line I03 to the cylinder I02 driving the piston therein toward the end of the cylinder and withdrawing the barrier. When the machine is released the valve stem is released by the withdrawal of the toggle and the air is exhausted from the exhaust ports I08.

Another form of operating the cylinder I02 is that of having a pipe leading from the main power cylinder 2! to permit passage of air from the power cylinder 21 through the pipe into the cylinder I02 when the piston has traveled a pre determined distance of its stroke. A spring s in the cylinder I02 returns the piston to the initial position when the valve is released and air eX- hausted to again insert the barrier between the arms 12 and 13.

In Figure 8 We have shown the use of a rubber or resilient member I09 filling the cylinder lfi and at all times forcing the head of the piston 8| toward the end of the cylinder but allowing for slight contraction thereof to take up any wear of the valve 82 and its respective seat.

Figure 10 shows a still further modified manner of taking up this wear constituting the same member I8 and finger 00 but with the finger 80 pressing against one side IIO of a double diaphragm chamber III, said chamber to be filled with constant air pressure from the line I I2 and with the diaphragm I i 3 engaging the valve 02.

In Figure 11 we have shown a sectional View of the control valve 04 with the ball valve shown as I04, the inlet pipe as I67, and the line I03 leading to the cylinder I02. This is the same valve as shown in Figure 8 showing the details a thereof.

In Figures 12, 13 and 14, we have shown another method of taking up the wear of the valve in the main control valve. In Figure 13 the valve is shown as 82a. and the ball valve as 8611, carried I in the casing shown as 41a; The stem 82a in this particular type of device is provided with adjustable control nuts shown as H9a which nuts are engaged by the annular flange H9 of the head H5. Within the head H5 there is a cylindrical chamber H6 carrying a rubber bladder or inner tube I! with the air line 92 leading thereinto and with the piston of Figure 1 replaced by a stem I [8 provided with a head inside the chamber. Thus, when the head I I5 is actuated by the whipplertee 15 the annular flange engages the nuts H9a and actuates the valve and when the valve has been opened and the pressing buck actuated the air passes through the line 92 and expands the inner tube forcing the stem H8 against the stem of the valve 82a to take up wear of the valve.

In Figure 14 this particular type of head is shown connected to the valve Hi l as shown in Figure 8 so that the air is supplied to the tube H1 through .a line I29 when the stem 35a has been engaged by any movable part of the machine such as the toggle links l6 or the boss I06. This particular valve I04 might be actuated by the buck arm 14 or any other movable part of the machine which moves when the movable buck is brought into contact with the stationary buck.

It will be obvious that the line iZll may be connected directly into the line N3 of Figure 8, if desired.

We have also found that the pressure required to break or crack the valves from their seats should be less than the amount of pressure required to bend any of the resilient parts or compress any of the resilient means employed in our several devices to seat the valves and follow up the wear of any of the various valves shown in our drawings.

As shown in Figure 3 the plate 10 may be made of resilient material to yield when the manuals are operated from intermediate to full operative position to take up any wear of the exhaust valve 82. Also the studs 53 and 69, the arms 12 and 13 and the links 16 and H, the head 75 or the support bracket forthe valve casing 4| may be made of some resilient medium if desired to take the wear of the valve 82 or its seat. It will be obvious that the valves 82 and 86 may be made of resilient material such as rubber or like material to take up any wear and that the seats in which the valves seat may also be made with rubber inserts for this same reason.

There are three positions of the manuals as used in this invention, namely: inoperative, intermediate, and full operative positions. The inoperative position is that position maintained when the manuals are idling and the device is not in use, as shown by the full line position in Figure 2. The intermediate position is considered that position to which the manuals are moved, from the inoperative position by the operator to cause movement of the head against the head member or near thereto but is not sufficiently advanced to engage the tension of the stem against the valve 82 an amount greater than just to crack the valve 86 and is not suflicient to compress or utilize the air in the chamber 79. The full operative position is that position shown in Figure 4 of the drawings where the manuals have been advanced sufiicient distance to throw the toggle links beyond dead center locking the manuals in the full operative position at which time the operator may remove the hands and leave the machine until it is desired to release it. It will further be seen that the operation of the machine is in two steps, (a) the manuals are movable from the full line position, or inoperative position to the intermediate position which brings the head to engage the bed, and (b) the manuals are movable from the intermediate position to the full operative position locking the head to the buck. The first step lowers the head into contact with the buck and the second step locks the manuals with the head in contacting pressing engagement.

While we have illustrated and described what we now regard as the preferred embodiment of our invention, the construction is, of course, subject to modification without departing from the spirit of our invention. We therefore, do not wish to restrict ourselves to the particular form of construction illustrated and described, but desire to avail ourselves of all modifications which may fall within the scope of the appended claims.

Having thus described our invention we desire to secure by Letters Patent and claim:

1. A pressing machine comprising head and bed members, at least one of which is relatively movable; operating mechanism therefor; and control means for said mechanism, including spaced manuals, movable from inoperative to intermediate position to substantially draw the head member to the bed member and thereafter to the full operative position; means governed by the relative position of the head and bed members controlling movement of the manuals from intermediate to full operative position; a source of pressure fluid connected with said operating mechanism; a single valve controlled by the combined movement of said manuals; and resilient means to take up wear of the valve and the valve seat in the operative mechanism.

2. A pressing machine comprising head and bed members, at least one of which is relatively movable to and from the other; operating mechanism therefor; and control means for said mechanism including spaced manuals, movable from inoperative to intermediate position and thereafter tofull operative position; a barrier controlled by the relative position of the head to the bed member to control the movement of the manual from the intermediate position to the full operative position a valve mounted in the path of the operating mechanism to be actuated thereby; and a hydraulic cylinder to control the position of the barrier.

3. A pressing machine comprising, head and bed members one of which is movable to and from the other; operating mechanism for said movable member; and control means for said mechanism including spaced manuals, movable from inoperative to intermediate position to actuate the movable member to near the other mem ber and thereafter to full operative position to lock the movable member into pressing contact with the other member; a source of fluid pressure for operating said mechanism; a pilot valve for controlling said fluid pressure; a whippletree actuated by said manuals to allow one of the other of said members ,to be pressed inwardly without effecting movement of said movable member but to be actuated when both manuals are operated; a slidable head attached to and operated by said whippletree; a cylinder in said head; means to introduce into said cylinder, fluid pressure, to maintain a constant pressure in said cylinder; and a piston in said cylinder having the stem extended out and adapted to engage the pilot valve stem when the whippletree has been operated.

4. A pressing machine as set out in claim 3, including a barrier hydraulically controlled by the relative position of the head and bed member, said barrier to be inserted to prevent movement beyond intermediate position of the manuals until the movable member has reached a safety position for the operator.

5. A pressing machine comprising head and bed members, one of which is movable to and from theother; operating mechanism for said movable member; and control means for said mechanism including spaced manuals; a valve control for fluid pressure for moving said movable member; toggle arms attached to and operable by said manuals; a Whippletree movable by said arms; a barrier adapted to be brought into position between said arms to prevent further inward movement thereof when the manuals have been moved from inoperative to intermediate position, said barrier being con-trolled by the relative position of the head and bed members and to be withdrawn when the movable member has reached a predetermined position to permit further overcenter movement of said toggle arms to lock the manuals in the full operative position; and resilient means to control the said valve.

6. A pressing machine as set out in claim 2, including a valve operated by the manuals to control the operating mechanism; and resilient means to take up the wear of said valve.

'7. In a control mechanism for pressing machines, the combination of spaced manuals; toggle lever devices connected with the end of each manual; a whippletree connected with the ends of said toggle lever devices; a sliding head pivotally mounted medially of said Whippletree; a fluid pressure cylinder in said head; a piston in said cylinder with the stem extending from the end of the head; means to connect the cylinder with a source of fluid pressure; and a pilot valve to be controlled by said piston stem.

OTTO H. PEARSON. ED PEARSON.

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