US2171559A - Control mechanism for pressing machines - Google Patents

Description

Sept. 5, 1939. R, H|G| EY 2,171,559

CONTROL MECHANISM FOR PRESSING MAGHINES- Filed Dec. 6, 1957 2 Sheets-Sheet 2 INVENTOR FRANK R. HIGLEY BY M ATTORN EYS Patented Sept. 5, 1939 UNITED STATES PATENT OFFHCE CONTROL MECHANISM FOR PRESSING MACHINES Frank R. Higley, Cleveland Heights, Ohio, as-

signor to The American Laundry Machinery Company, Norwood, Cincinnati, Ohio, a corporation of Ohio Application December 6, 1937, Serial No. 178,205

8 Claims.

I operated position and means whereby the spring means is moved to ineffective position When the press is safely closed. In one particular embodiment of my invention stop means is provided preventing movement of the manual beyond intermediate position until the press is safely closed and the spring means is carried by this 'stop means.

Another special feature of my invention is the embodiment of the above described novel control features in a safety two-hand control for a pressing machine.

A modified form of my invention applies the spring return of the manuals from intermediate to unoperated position in combination with a four-bar linkage connected between a pair of safety manuals and a power control member in such a fashion that actuation of both safety manuals coincidentally is required to move the control member to power supply position. Other novel features connected with this four-bar linkage are applicable to the control of any power machine.

Other novel features of my invention will be apparent from the accompanying drawings and the specification and the essential features will be set forth in the claims.

In the drawings, Fig. 1 is an end elevation of a pressing machine equipped with my invention, wherein the control mechanism is shown diagrammatically with the press in open position; Fig. 2 is a similar View showing in full lines the press in safe closed position and in dot-dash lines the fully closed position of the press, the control mechanism being shown in corresponding position diagrammatically; Fig. 3 is a view of the control mechanism of Figs. 1 and 2 corresponding to fully closed position of the press; Fig. 4 is a detail view of the stop means of Figs. 1 and 2; Figs. 5 to 8 show a modified form of control mechanism omitting the showing of the press which may be the same as in Figs. 1 to 4; Fig. 5 shows in full lines the control parts in unoperated position and in dot-dash lines a false operation of the parts; Fig. 6 shows the control mechanism in position corresponding to safe closed position of the press; Fig. '7 shows the parts in position corresponding to fully closed press position; while Fig. 8 is an elevational view of the four-bar linkage and valve of Figs. 5 to '7'.

In the modification of Figs. 1 to 4, on a machine frame it is mounted a pressing bed H. The frame also carries a pivoted lever or yoke 42 upon which is mounted a pressing head l3 adapted to coact with the bed II upon oscillation of yoke l2 by means of the toggle I4 and the con- 1 nected fluid motor iii. A spring l6 normally biases the head toward open position. The fluid motor is of the cylinder and piston type having its piston rod connected to the toggle l4. Fluid is supplied to this motor through conduit l1 and valve casing l8. This casing houses a normally closed inlet valve l8a closed by a ball, as shown in the various figures, and a normally open outlet port [81) which may be closed by a shoulder on the valve stem I80. This valve stem is actuated by a pin 19a on an equalizer bar l9 acting through a spring device 20. It will be understood that the equalizer bar and its pin are suitably mounted in the frame for motion toward and from valve stem l8c. ably operated by a pair of spaced safety manuals 2| pivotally mounted on the frame at 22 so as to require a hand of the operator on each manual for their coincidental operation. In the form shown, each manual is in the form of a bell crank having an arm 2m carrying a roller Zlb, these rollers engaging opposite ends of bar l9. Movement of these manuals from the unoperated position of Fig. 1 to the intermediate position of Fig. 2 moves pin l9a sufficiently to close valve Hit) and to open valve l8a provided both manuals are actuated coincidentally. Movement of the manuals beyond this point is prevented by the movable stop means 23 lying between the bell crank arms Zla. It will be understood that this stop 23 is pivotally mounted'on the frame ii) for vertical movement into and out of position between the arms Zla. The movement of the valves to the position of Fig. 2 supplies fluid to motor [5 and causes relative approach movement between the pressing members. However if either of the manuals is released the motor l5 will be evacuated and the press will open under the influence of spring Hi. This is accomplished because on the stop 23 are mounted the flat Equalizer bar I9 is prefertion, means is provided for removing stop 23 and rendering springs 24 ineffective, whereupon the manuals may be moved to fully operated position. The mechanism shown for this purpose comprises a rod 26 connected with stop 23 and carrying collars 26a and 26?) adapted to engage the bracket Ma on toggle i4 Spring 2'! normally biases the stop 23 to the position of Figs. 1 and 2 between the arms Zia. When the press reaches safe closed position collar 26a is engaged by bracket Ma and further movement of toggle i l in press closing direction removes stop 23 in a downward direction so as to permit movement of manuals 2| to the position of Fig. 3. In moving from the the position of Fig. 2 to that of Fig. 3, arms Zia pass over their dead-center position and engage against suitable stop means 28 on the frame. The spring device 28 yields to permit this overcenter movement of arms 2 la. The parts will remain in the position of Fig. 3 as long as it is desired to hold the press closed due to the pressure of the fluid supply on valve stem I and also because the arms Zia cannot return over center without compressing spring 2!]. To open the press the manuals 2i are returned to the position of Fig. 1 to evacuate motor i5 and permit spring IE to open the press.

In the modification of Figs. 5 to 8, it will be understood that motor i5 is connected to a pressing machine constructed like that of Figs, 1 and 2 and supplied from conduit 25 through valve casing i8 and conduit I1. Here again the stop member 23 is connected with the press parts so that the stop normally lies in the position of Figs. 5 and 6 but is removed as shown in Fig. '7 when the press reache safe closed position. Here the safety manuals are indicated at 29 and are connected by a four-bar linkage so as to actuate the pin 30 which has a yieldable connection with the valve stem I80. In the form shown, two bars of the four-bar linkage ar formed by the bell crank arms 250. connected with the manuals 253 The other two links 3i are pivotally connected at 32 to the arms 29a and are pivotally connected together at 33. ,The two manuals are pivotally mounted on the'frame at 34. Referring toFig. 5 it will be noted that if one manual alone is operated, the four-bar linkage will cause the roller 33a carried by the pivot connection 33 to move to one side of pin 36 so that the valves are not actuated, but if both of the manuals are moved coincidentally to the position of Fig. 6, roller 33a engages pin 30 and moves the valves in casing ill to operated position so as to supply fluid to motor i 5, causing press closure. Stop 23 at this time prevents movement of manuals 29 beyond the position of Fig. 6 and if either or both of the manuals is released, springs 24 on the stop 23 (which are loaded in Fig. 6) will return the manuals to unoperated position. However, when the press is safely closed, stop 23 is removed as previously described, permitting movement of manual 29 to the fully operated position of Fig. 7. Here the sides of the four-bar linkage have crossed, that is to say, each part of the linkage has passed dead-center to a position limited by shoulders 35. The four-bar linkage will be held in this position by the yieldable connection between pin 30 and valve stem I80 and also by the action of the air on the ball valve i8a. The manuals may then be released and the press will remain closed. To open the press the manuals are returned to the position of Fig. 5.

What I claim is:

1. In a pressing machine having relatively 'movable pressing members, having power means for causing said relative movement from open position through a safe-closed position to a pressure position, and having a control member for said power means, actuating mechanism for said control member comprising two spaced manuals at least one of which has two stages of movement, said manuals during first stage movement of said one manual from unoperated to an intermediate position producing operation of said power means and relative approach movement of said pressing members, and by second stage movement of said one manual to full operated position maintaining said members in pressure position, means governed by the relative position of said pressing members for controlling movement of said one manual from intermediate to full operated position, and means carried by said last named means for moving said one manual from intermediate to unoperated position.

2. In a pressing machine having relatively movable. pressing members, having power means for causing said relative movement from open position through a safe-closed position to a pressure position, and having a control member for said power means ,actuating mechanisms for said control member comprising spaced safety manuals at least one of which has two stages of movement, said manuals during first stages movement of said one manual from unoperated to an intermediate position producing operation of said power means and relative approach movement of said pressing members, and by second stage of said one manual to full operated position maintaining said members in pressure position, spring means normally effective to move said one manual from intermediate to unoperated position, and means responsive to relative movement of said pressing members to safe-closed position for controlling movement of said one manual from intermediate to full operated position and for rendering said spring means ineffective to move said one manual to unoperated position.

I 3. In a pressing machine having relatively movable pressing members, having power means for causing relative movement of said members from open position through a safe-closed position to a pressure position, and having control means for said power means normally in power cut-off position, actuating mechanism for said control means comprising a pair of manuals spaced apart for two-hand safety operation, said manuals having two stages of operation, a first stage from unoperated to an intermediate position and a second stage from intermediate to full operated position,

said manuals being opera ively connected with I said. control means to require coincidental first stage, actuation. of both manuals to move said control means to power-supply position, spring means for moving said manuals from intermediate to unoperated position, stop means normally preventing second stage movement of said manuals, and means responsive to movement of said pressing members to safe-closed position for moving said stop means and said spring means to ineffective position.

4. Control mechanism for pressing machines as in claim 3, in which said spring means is carried by said stop means.

5. In a pressing machine having relatively movable pressing members, having power means for causing relative movement of said members from open position through a safe-closed position to a pressure position, and having control means for said power means normally in power cut-off position, actuating mechanism for said control means comprising a pair of manuals spaced apart for two-hand safety operation, said manuals being movable each to opposite sides of a dead-center position, from a stable unoperated position on one side of dead-center to a maintained operated position on the other side of dead-center, the arrangement of said manuals and said control means being such that coincidental movement o-f both manuals to an intermediate position short of dead-center moves said control means to power-supply position, stop means normally preventing movement of said manuals beyond said intermediate position, spring means on said stop means engaging said manuals to return them to unoperated position, and means for removing said stop means to ineffective position by relative movement of said pressing members to safe-closed position.

6. Control mechanism for pressing machines as in claim 5 in which said manuals are bell cranks rotatable toward each other, and said stop means normally lies between said bell cranks.

7. Control mechanism for pressing machines as in claim 5 in which said control means is a single member, and an operative connection is provided between said manuals and said single member comprising a four-bar linkage operable by said manuals and requiring coincidental operation of both manuals to cause said linkage to engage and operate the said member.

8. In a pressing machine having relatively movable pressing members, having power means for causing said relative movement, and having a control member for said power means, actuating mechanism for said control member comprising a pair of manuals spaced apart for two-hand safety operation, and a four-bar linkage operatively connected between said member and said manuals, the parts being so arranged as to re quire coincidental actuation of both manuals to cause said linkage to engage and operate said member.

FRANK R. HIGLEY.

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