US1209381A - Starting and stopping mechanism for presses. - Google Patents

Description

APPLICATION FILED FEB. 9, I914.

Patented Dec. 19, 1916.

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ARTHUR BATES, OF LEICESTER, ENGLAND, ASSIGNOR TO UNITED SHOE MACHINERY COMPANY, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Dec. 19, 1916.

Application filed February 9, 1914. Serial No. 817,543.

stopping mechanisms and particularly to.

starting and stopping mechanisms which are especially adapted for use in controlling the operation of presses of the type variously known as revolution presses, mo mentum presses, gearless sole cutting machines, etc. A general characteristic of this type of press is that the relative movement of the platen or beam and the table or support is effected by connections with a single shaft, to which a heavy, rapidly rotated fly-wheel may be connected at the'will of the operator, and during a single revolution of said shaft, the platen operating to engage a die or the like located upon sheet material supported on the table or support to effect the cutting operation. As usually constructed presses of this kind are driven from a power-actuated pulley through a clutch which is put into operation by an actuating member, such as a treadle. It is necessary in the operation of the machine, in order to avoid damage to the work and danger to the workman, that the clutch shall be released in time so that the driving shaft will make but a single complete revolution and thereby effect a single pressing operation, and with this purpose in view safety means have been adopted in presses of this type to prevent a further operation of the machine whether or not the actuating member is maintained in the position to which it has been moved to startthe machine. An example of such means is shown and described in United States Patent No. 1,194,379, granted August 15, 1916, upon the application of Joseph Gouldbourn and Arthur Bates.

An object of the present invention is to provide improved means for accomplishing this purpose, said means being simple in construction and acting in a more efiicient and reliable manner than the devices heretofore employed in machines of this class for accomplishing this object.

An important advantage of the means forming the subject-matter of this invent1on is that the safety device is capable of ready application to existing machines.

In the accompanying drawings,Figure 1 is a perspective view of the essential parts of the mechanism constituting the subjectmatter of the invention, this view showing the lower part of the right-hand end of a press having embodied therein the preferred form of the invention; and Fig. 2 is a detail, in elevation, showing the connections between the brake operating mechanism and the stop by which the braking action is in creased in the event of overthrow of the machine.

The machine in which the invention is embodied is of the general type shown in United States Letters Patent to Henry Parsons, No. 368,108, granted August 9, 1887, and only so much of the machine is herein shown as is essential to an understanding of the principles of operation of the invention.

The frame 2 of the machine supports, in the usual manner, a cutting block, not shown, on which the work to be cut is placed, and a platen or beam, not shown, is arranged above the block and is supported near its corners by rods 1-, of which the lower ends are shown in the drawings, a cross piece 6, connecting the lower ends of these rods, being provided with a slot 8 in which is received the lower end of an eccentric strap 10 connected to said cross piece 6 by a pivot pin 12. The eccentric strap 10 receives an eccentric 14 upon the driving shaft 16 and by means of this eccentric the platen is reciprocated to efiect the cutting operation.

The main shaft 16 also carries a brake drum 18. It is necessary, in the operation of a press of this type, that the platen shall make only a single reciprocation, that is, that it shall only move down from its position of rest into engagement with the die and then return to its position of rest lest the operator place his hands under the platen as it returns to its uppermost position and have them injured during an accidental second downward movement. Means have been employed in machines of this character to insure that after the actuating member, usually a treadle, has been operated the press will make but a single pressing movementto its initial position and then again moved 7 V in the actuating direction.

Further, the

machines have been so arranged that the continued operation of the actuating member, as for example, by maintaining the treadle depressed, will only have the effect of causing a single pressing movement of the platen, the latter when raised afterpressing being automatically disconnected from its actuating mechanism and requiring afurther operation of the actuating member. According to the )resent invention the press is operated in tne manner just described, the arrangement of the mechanism, however, being such that it is superior in operation and safer in use than the constructions heretofore employed.

In accordance with the present invention, the brake drum 18 is surrounded by a brake band 20 which is pivoted at 22 to a link 24 that is fulcrumed on'a pin 26 in the frame of the machine. The ends 28 and 30 of the brake band are connected together by a coupling device that includes a floating lever 32. When the end of the floating lever 32 is raised the brake band 20 is closedaround the drum and the brake is thus applied. The

floating lever 82 is connected at 3% to one of the elements 36 of a toggle, the lower end of the other element 38 of said toggle being secured to a rock-shaft 40 mounted in bearings in the frame of the machine. The rock-shaft i0 is turned by a spring connection, not shown, in such a direction as to tend normally to'maintain the toggle in its broken condition. and therefore to maintain the brake band inoperative. This action of the rock-shaft 40 serves also, through connections, not shown, to force together the parts of a driving clutch, also not shown, with a pressure determined by the spring connection by which the rock-shaft 40 is turned. The driving clutch may be con nected to the rock-shaft 40 through suitable arms and links, such as are commonly employed in this type of machine.

As will hereinafter be more fully eX- plained, particularly in connection with the description and operation of the machine, the rock-shaft 40 is at times turned positively in opposition to the spring which tends to maintain the toggle in broken con dition, in order to separate the parts oftheclutch and thereby disconnect the machine from the power and at the same time apply the brake by straightening the toggle.

The treadle 12 by which the machine is started is mounted so as to turn freely on the rock-shaft 40. the treadle being provided with an arm 44 that extends upwardly from said rock-shaft. Pivoted at l6 between ears upon the upper end of the arm 44 is a clutch tripping member 48 that extends across the The clutch tripe ward and backward as the treadle is lowered and raised. The clutch tripping member is provided with a trip face 50 formed upon the front end of a sleeve 52 which surrounds the member 48 andis clamped upon said member by a set screw 54. 'The face 50 is adapted to engage a corresponding face on a small lever or dog 56 pivoted on the pin 12 by which the eccentric strap 10 is connected to the cross bar 6. The member 48 is arovided with a fin er 58 a ainst which ears a spring-pressed plunger 60 which is situated in a recess in a boss 62 in the arm 14,-. The spring-pressed plunger tends to turn the member 18 about its pivotG and so insure that itstrip face 50 shall engage the trip face upon the dog 56; A springpressed plunger 64 mounted in an secured to the cross bar orcross. head 6 tends normally to turn the dog'56 toward the rear of the machine so that ;when the cross head has been lowered an abutment face 68 with which said dog is provided will be brought beneath a corresponding abut ment face 70 on an arm 72 fixed to the rockshaft 4-0. hen the abutment faces 68 and '70 are in this relationship, the rising of the cross head 6 after the pressing operation will cause the arm 72 to turn the rock-shaft 40 and thereby straighten'the toggle to, apply the brake and at the same time unclutch the driving pulley. 1 1

To insure that the brake shall be applied with suiiicient force to stop the machine and to guard against wear or improper adjustment of the brake band preventing the brake from working properly, a, finger-74l is fillcrumed on the pivot 76 of the toggle 36, 38. This finger is supported at its outer end by a link? 8 connected with an arm projecting forward from the lower toggle element 38 which thus, with said arm. forms a bellcrank lever. 'lVhen the toggle is moved in the direction to of the center joint drum' with the stop faceS'Z upon the finger 74.- will further straighten the toggle and apply the brake with increased pressure. To permit the movement of the toggle 36,

38 during this further straighteningmove- V ment, notwithstanding its connection with the fingeril through the arm 80, the link 78 is made capable of angling and yielding.

For this purpose the link 7 8 is pivoted to the finger 7 4 and passes through a block 86 pivoted in the arm 80, the link being provided with a nut or head below the block 86. A spring 88 is interposed between the block 86 and a nut 90 which is screwed on to a threaded portion of the link so that normally the link is held extended to an extent determined by the nut or head at its lower end and the finger is positioned accordingly. The spring 88 by yielding permits the further straightening movement of the toggle arm when the faces 82 and 84 of the finger and drum are in engagement.

The device,already referred to for connecting the ends of the brake band comprises, as aforesaid, the floating lever 82. This floating lever is pivoted at 92 to the end 28 of the band and the end 30 of the said band is pivoted to a rod 94 that passes through a hole in a block 96 pivotedin the lever 32. The rod 94 is screw-threaded and nuts 98 screwed on to it above the block provide means for adjusting the band about the drum, a spring 100 being located on the rod 94 between the block 96 and its connection with the end 30 of the band 20 to hold the nut 98 in contact with the block. When the end 84 of the lever 32 is raised, it not only acts as a lever of the first class to draw the end 28 of the band downward, but also as a lever of the second class to draw the end 30, through the medium of the rod 94, upward.

In the operation of the machine, the workman, after arranging the work and dies upon the table, depresses the treadle 42 whereby the arm 44 moves the clutch tripping member 48 toward the front of the machine. In this movement the trip face 50 on the said member engages the trip face on the dog 56 and turns the latter on its pivot pin in opposition to its spring-pressed plunger 64. Turning of this dog removes the abutment face 68 on the dog from the abutment face 70 on the arm 72, thus allowing the rock-shaft 40 to be turned by its spring connection hereinabo-ve referred to, but not shown, so that the brake is removed from the drum by the breaking of the toggle 36, 38, the lower member 38 of which is connected to said rock-shaft 40. At the same time the rocking of the shaft 40, through its connections to the clutch, not shown, serves to actuate the machine. When the driving shaft 16 begins to turn, the eccentric 14 on said shaft depresses the cross head 6 to lower the platen to effect the cutting operation, and in this movement the trip face on the dog 56 moves below the range of the trip face 50 on the clutch tripping member 48 so that the spring-pressed plunger 64 is free to move the dog 56 to bring the abutment face 68 into a position to engage with the abutment face 7 0 on the arm 72 fixed to the rock-shaft 40 when the cross head 6 reaches the bottom of its stroke. Upon the upward movement of the cross head 6 the abutment face 68 engages the abutment face 7 0 and, by turning the rockshaft 40 positively in opposition to its spring operating means, unclutches the driving pulley from the shaft 16 and moves the toggle 36, 38 toward its straightened position whereby the brake is applied.

In order to prevent the dog 56 from being turned on its pivot during the upward movement of the cross head 6 by its engagement with the face 70 and under the influence of the plunger 64, the said dog is provided with a face 102 which is adapted to engage a projection 104 on the arm 65. The parts will remain in this position until a further operation is required. To accomplish this, the treadle must be raised before the machine can be started in order to carry the trip face 50 on the member 48 into a position to again engage the trip face on the dog 56 when the treadle is next depressed. It will thus be seen that the connection between the treadle and the clutch tripping parts of the machine is broken after the machine is operated through a complete cycle, and it is immaterial whether the workman maintains the treadle depressed or not. Should the brake fail to be applied with sufiicient force to stop the machine, the stop face 84 on the brake drum will engage the stop face 82 on the finger 74, which has been lifted by the movement of the toggle 36, 88, and thereby exercise a further braking power by a further movement of the toggle toward its straightened position. In the operation of this mechanism, which constitutes a safety device and only becomes operative when the machine is working imperfectly, before the machine can be restarted the finger must be moved out of contact with the stop face on the brake drum. This may take place automatically by reason of the rebound of the parts, leaving the finger free to fall, or it may be accomplished manually by turning the brake drum slightly in the reverse direction.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is 1. Starting and stopping mechanism comprising, in combination, clutch controlling means, means for automatically restoring said clutch controlling means to clutch releasing position at the end of a single operation of the machine, a brake, connections between said clutch controlling means and said brake comprising a toggle arranged to be moved toward straightened position to apply the brake as the clutch controlling means moves into clutch releasing position and to be broken as the clutch controlling means is moved into clutch applying position, and means brought into operative condition as the clutch controlling means is moved into clutch releasing position for moving said 7 machine at the end of one cycle of operations.

2. In a machine of the class described, comprising a driving shaft and a reciprocating part operated from said shaft, clutch controlling means comprising a member connected to said reciprocating part and operating upon the return of said part to its normal position of rest to move said clutch controlling means into clutch releasing position to stop the machine at the end of a single reciprocation of said, part, a brake, connections between said brake and said clutch controlling means comprising a toggle arranged to be moved toward straightened position as said clutch controlling means is moved into its clutch releasing position, a stop member connected to the knee joint of said toggle, a second stop member arranged to turn with said shaft, and means operating to move the first stop member into the path of the second stop member as said clutch controlling means is moved into clutch releasing position, whereby said toggle will be movedfarther toward straightened'position to increase the braking action if said shaft does not stop at the end of complete rotation.

3. In a machine of the class described, clutch controlling means, means for automatically and positively moving said clutch controlling means into clutch releasing position at the end of a single operation of th machine, a brake, means for operating said brake comprising a toggle, and means connected to the knee joint of said toggle and automatically interposed in the path of a moving part of said machine, as the clutch is released, for increasing thebrake applying operation of said toggle in the event that the machine does not stop at the end of a single operation.

4. Starting and stopping mechanism com; prising, in combination, a brake, brake applying means including a toggle arranged to be moved toward straightened position to apply the brake, and means connected to said toggle and automatically moved into the path of a moving part of the machine as the brake is applied, said means being so constructed and arranged that the toggle is moved farther toward straightened position to increase the braking'action in the event Copies of this patent may be obtained for five cents each, by addressing the Washington, D. 0.?

that saidnioving part of the machine tends to move beyond its normal position of rest. 7 5. In a machine of the class described, a brake drum, a brakeband, and means for tightening said brake band upon said'brake drum to exert a braking action'comprisinga toggle arranged to be moved toward straightened position for this purpose, a stop upon said brake drum, and a second stop connected'tothe knee joint of said toggle and adapted to be moved into the path of movement of the stop on said drum whereby the toggle may be moved farther toward straightened position to increase the braking action in the event that said drum turns beyond its normal position of rest.

6. In a'machine of the class described, a

brake drum, a brake band, and means for tightening said brake band upon said brake drum to exert a braking action comprising 7 a toggle arranged to be moved toward straightened position for this'purpose, a stop upon said brake drum, a second stop connected to the knee joint of said toggle and adapted to be moved into the path of movement of the stop on said drum whereby the toggle may be moved farther toward straightened position to'increase the braking action in the event that said drum turns beyond its normal position of rest, and-means connected to one of said toggle members for moving said second mentioned stop into the path of movement of the first mentioned stop as the toggle is straightened to apply the brake. r

7. In a machine of the class described, a reciprocating part, a rock-shaft, brake app ying means operatedfrom said rock-shaft, said rock-shaft being arranged to be turned normally in a brake releasing direction, 7.

means connected to said reciprocating part for engaging and turning said rock-shaft in a brake applying direction and for maintaining said rock-shaft in its brake applying position when the machine is at rest, and manually operated means turning upon said rock-shaft for breaking the connectionbetween said reciprocating part and said rockshaft whereby the brake is released. 1

In testimony whereof-I have signed my name to this specification in'the presence'of two subscribing witnesses. r

ARTHUR Barns; Witnesses FREDERICK WILLIAM l VORTH; V BASIL POMEROY Coornn.

Commissioner of Patents,

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