US2698680A - Starting and stopping mechanism for presses - Google Patents

Description

1955 A. s. CLARK STARTING AND STOPPING MECHANISM FOR PRESSES 3 Sheets-Sheet 1 Filed April 2, 1952 neg Inventor Alfred J? Clark Jan. 4, 1955 A. s. CLARK 8,

STARTING AND STOPPING MECHANISM FOR PRESSES Filed April 2, 1952 3 Sheets-Sheet 2 Ihvenior //6 /1/f1-ed S. Clark I his jzorne Jan. 4, 1955 A. s. CLARK 2,698,680

STARTING AND STOPPING MECHANISM FOR PRESSES Filed April 2, 1952 5 sheetksheet 3 \J I K 8 Inventor Alfred 6. Clark United States Patent STARTING AND STOPPING MECHANISM FOR PRESSES Alfred S. Clark, Beverly, M-ass., assignor to United Shoe Machinery Corporation, Flemington, N. 1., a corporation of New Jersey Application April 2', 1952, Serial No. 280,113

2 Claims. (Cl; 192-129).

This invention relates to starting and stopping mechanism and more particularly to starting and stopping mechanism adapted for use in. presses of the type illustrated in United States'Letters Patent No. 1,652,229 granted December 13, 1927 upon application filed in the name of Milton H. Ballard. In presses of the type referred to considerable difli'culty has heretofore been experienced in preventing overthrow or back down. of the heavy beam of the press which is usually reciprocated by eccentrics toward and away from a cutting block. In such machines it is desirable that the beam normally be brought to a position of rest after a single operation of the'reciproeating means with the beam in position in predetermined relation above the block surface. If the beam should overthrow beyond the position of rest or should back down from it there is considerable likelihood of injury to an operator by reason of the fact that he may have his fingers caught between the beam and the block. Although a number of devices have been designed. to overcome this difliculty none of them, so far as is known, has been completely successful.

It is an object of the present invention to provide in a machine of the type referred to, improved mechanism for bringing the beam to rest in its uppermost. position heightwise of the block and for maintaining the beam in that position until a further operation is intentionally initiated by the operator. the. invention provides locking mechanism in the form of cooperating wedge members for engaging the beam or a part associated with it for locking the beam in. stationary position, the locking mechanism being effectively operated at the termination of the single cycle. of operation of the beam.

These and other features of the invention are disclosed in the following specification and in the. accompanying drawingsand are set forth in the claims.

In the drawings,

Fig. 1 is a view in front elevation illustrating a press embodying one form of my "invention;

Fig. 2 is an end view partly in section of the machine shown in Fig. 1;

Fig. 3 is a side elevation partly in section of a portion of the clutch mechanism;

Fig. 4 is an end view, partly in section, of a portion of the control mechanism of the clutch; and

Fig. 5 is a plan view partly in section of the treadle and its associated mechanism.

The illustrated machine, as best shown in Fig. l, is a sole cutting press comprising a frame carrying a horizontal bed 12 upon which is positioned a cutting block 14, there being a beam 16 mounted upon four vertically extending rods 18 for reciprocation toward and away from the cutting block in pressure applying operations upon cutting dies, not shown, which can be positioned upon sheet material such as leather on the block thereby to produce sole blanks or other blanks. The beam is reciprocated by means of crossheads 20 to which the rods 18 are connected, the crossheads being arranged for vertical movement by means of eccentric rods 22 operatively connected to eccentrics 24 on the drive shaft 26. Operation of the shaft is initiated by depression of a treadle 28 which acts through treadle rods 30, bell cranks 32 to shift a starting rod 34 in a direction to cause a clutch trip lever 36 to place a clutch 38 in operative engagement with a flywheel 40. Depression of the treadle also effects rotation of a roekshaft 42 in adirection to withdraw a brake lever 44 in a directlon to To this. end and as illustrated r vided with a pin 90, Figs. 1,

I vide an outwardly inclined cam surface 108 to the left in Fig. 1 thereby to maintain the clutch in- Whenthe beam rises the cam leaves the roll and a spring 54 releases the clutch thus discon from the shaft and the rockshaft 42 close engagement.

necting the flywheel is rotated in a direction to apply the brake 46.

In'order to release the treadle after a clutch operation has been initiated a novel treadle assembly has been provided. This treadle assembly includes two arms 56, Fig. 5, loosely mounted upon the rockshaft 42 at points near opposite ends of the machine. The treadle isnormally urged upwardly by springs 57 extending be tweenthe arms 56 and a horizontal portion of the frame; There is also loosely mounted upon the rockshaft a bracket comprising together by a rod 60. Each of the arms 58 has an elongated slot 62 at its outer end arranged to receive a pin 64mounted upon an arm 66 loosely carried upon a stud 68 mounted in a bearing 70 in an arm 56. The inner endof this stud carries a latch 72 a latch plate- 74 upon a rockshaft the rockshaft at 78; The rockshaft arms 76 are connected to the lower ends of springs 80 the upper ends of thehsprings being connected to a portion of the frame in sue wardly thus tending torotate the rockshaft in a clockwise direction, Fig. 2. The lower ends of the treadle rods- 30 are connected to move the bell crank 32 in a direction'to disengage the clutch. Upward movement of the rockshaft arms islimited by two stop plates 82. The arrangement is such that when the treadle 28'is depressed against the action of the'springs 80, the latches 72 in engagement with the latchplates 74 will force the shaft to trip the clutch. Upon further downward move-- ment of the treadle the latches 72 slide off the latch plates'and' release the rockshaft for independent move-- most position heiglrtwise of the cutting block comprises; a wedge device which is releasable to permit reciprocal-- end eachcrosshead is pro tion of the beam. To this 2 and 3, extending inwardly and having secured thereto a slide 92 arranged to be movable in a vertical direction in ways 94 carried by a bracket 96 forming part of the frame. The bracket has an elongated opening 98 extending heightwise of the bracket and through which the pin extends thus to provide for clearance during reciprocation of the crosshead and pin as shown in Figs. 2 and 3. The locking device includes a locking lever 100 mounted upon a stud 102 on the frame and carrying two projections 104, best shown in Fig. 3, between which is positioned a roll 106. On one side of the roll the bracket is cut away to proand the slide 92 is also cut away at its upper portion at 109 to provide clearance.

The construction is such that when the slide is in the position shown in Fig. 2 and the lever 100 has been revolved into the position shown with the roll adjacent to a vertical side face 110 of the slide a spring 112 tends to force the lever with its roll in a downward direction, and the roll engages with the cam 108 and the face 110 simultaneously acting as a wedge tending to prevent relative movement of the slide and the parts surrounding it. Thus if there is any tendency of the slide to move up or down from its position shown in Fig. 2 friction between the slide, the roll and the cam serves to prevent such action. On the other hand when the slide is in the Patented Jan. 4, 1955.

46-from: engagement with-a brake drum:

two arms. 58 connected for rotation arranged to engage arm 76 splined toamanner that the arms are normally urged up--- l to the rockshaft and under the action of thesprings 86 are normally forced upwardly;

rockshaft arms 76' downwardly to effect counterclockwise movement of the rockv of the latches permits movement of the pm 64 and its arm 66 about the axis of the stud parts of the machine in a manner hereposition shown in Fig. 3 as is the case when the beam of the machine approaches its lowermost position, the slide has been moved downwardly until the recessed portion thereof is opposite the roll and the roll thus does not engage the slide and has no elfect in preventing movegient of the slide or its associated parts including the eam.

The position of the beam in which this wedging action takes place is dependent upon the position of the roll with respect to the face 110 of the slide and is in part controlled by the point in the cycle of movement of the slide and in the position of the lever 100. The uppermost position of wedging engagement of the roll, assuming that the slide has been moved substantially to its uppermost position, is readily controlled by limiting, counterclockwise, the lever 100 which is conveniently accomplished by a stop in the form of a set screw 114.

In order to effect operation of the lever 100 at the proper time in causing action of the roll either in releasing the slide or locking it in stationary position, there is provided a releasable connection between the rockshaft 42 and the lever 100. This connection comprises a link 16, Figs. 2 and 5, the lower end of which is mounted upon a pivot 118 extending through a recessed portion 120 of an extension 122 on the rotary bracket 58. The link 116 extends upwardly through an opening 124, Fig. 4, in an outer portion 126 of the locking lever 100. The upper end of the link is recessed at 128 to form a vertically extending surface 130 and a relieving recess 132. The opening 124 of the lever has an outer inclined wall, shaped somewhat similar to that of the wall 108 and there is provided a lever 134 pivoted at 136 on the locking lever and carrying studs 138 having between them a roll 140 similar to the roll 106. The lever 134 is normally forced in a clockwise direction by spring 142 with the result that the roll 140 is normally wedged between the surfaces 124 and 130 to secure the locking lever and the link 116 so that they will move together. However, when the lever 134 is moved in a counterclockwise direction the roll will be released and the link 116 can be moved up or down relatively to the lever 100 with the parts in the positions as shown in Figs. 2 and 4. When the treadle 28 is depressed the link 116 being connected to the lever 100 by the wedge device effects rotation of the lever 100 in a clockwise direction, thus releasing the beam for movement heightwise of the block.

In order to permit return of the locking lever 100 into operative position at the end of a reciprocation of the beam, mechanism is provided for releasing the wedging device for locking the lever. To this end, the lever 134 has a tail portion 144 projecting beneath the pin 90. In view of this when the beam approaches its lowermost position the pin 90 engages the tail portion sufliciently to rotate the lever 134 in a counterclockwise direction, Fig. 2, to release the roll 140 with the result that the link 116, is no longer secured to the locking lever 100 but may slide relatively thereto. This effects release of the bracket 58 and a spring 150 moves the bracket upwardly and also moves with it the link into its uppermost posltion. When the beam is again moved upwardly the pin and slide also move upwardly and the pin, in engagement with the tail 144 as it moves upwardly, gradually permits the spring 142 to rotate the lever 134 in a clockwise direction until in the uppermost position of the slide, the roll is once again moved into wedging position between the surfaces 124 and 130, thus to lock the roll 140 to the lever 100.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a press comprising a frame, a bed mounted in the frame, a beam mounted for reciprocation toward and away from the bed, a drive shaft, eccentrics on the shaft, links operatively connecting the eccentrics and the beam for reciprocating the beam upon rotation of the shaft, a flywheel, and a clutch, for connecting the shaft to the flywheel, a treadle for initiating operation of the clutch in combination with beam locking mechanism comprising a slide constructed and arranged to reciprocate with the beam, the frame having a face inclined relatively to a face of the slide, a lever, a roll carried by the lever, means for moving the lever to position the roll in engagement with said faces of the slide and frame thereby to lock the beam against movement, and a second lever operatively connecting the first-mentioned lever and the treadle responsive to operation of the treadle to effect release of the roll thereby to unlock the beam.

2. In a press comprising a frame, a cutting bed carried by the frame, a beam mounted for reciprocation toward and away from the cutting bed, a drive shaft, power means for rotating the shaft, means operatively connecting the power means and drive shaft for effecting reciprocation of the beam, the combination with beam locking mechanism comprising a slide member constructed and arranged to reciprocate with the beam and having a substantially vertically extending face, the frame having a face inclined relatively to the said face of the slide member, a lever mounted adjacent to the slide member, a roll carried by the lever and positioned between the two faces, means normally operative to move the lever in a direction to cause the roll to engage both of said faces with a wedging action thereby to prevent relative movement between the slide and frame, a treadle for initiating rotation of the drive shaft, and means operable in response to operation of the treadle for causing the lever to release the roll thereby unlocking the slide member.

References Cited in the file of this patent UNITED STATES PATENTS 1,332,856 Pflanze Mar. 2, 1920 2,009,151 Reed July 23, 1935 2,142,113 Criley Jan. 3, 1939 2,246,021 Sturm et al. June 17, 1941 2,590,486 Aubert Mar. 25, 1952

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