US3732989A

US3732989A - Lift control system for press unloader or the like

Info

Publication number: US3732989A
Application number: US00147367A
Authority: US
Inventors: H Cagle
Original assignee: SAHLIN ENG CO Inc
Current assignee: SAHLIN ENG CO Inc
Priority date: 1971-05-27
Filing date: 1971-05-27
Publication date: 1973-05-15
Anticipated expiration: 1990-05-15

Abstract

There is herein disclosed a lift control system for a press unloader having an extendable and retractable jaw means for gripping and removing a part from the die cavity of a press with pivotal frame means supporting the jaw means for pivotal movement to lift the part from the die cavity and interconnected air operated power cylinder means to sequentially extend the jaw means, grip the part, lift the part, and retract the jaw means.

Description

United States Patent 1191 Cagle [4 1 May 15, 1973 [54] LIFT CONTROL SYSTEM FOR PRESS 3,178,040 4/1965 Nelson ..214/1 BB UNLOADER OR THE LIKE 2,763,229 9/1956 Sahlin ..214/l BB X [75] Inventor: Harlan R. Cagle, Clarkston, Mich. Primary Examiner Gerald M Forlenza [73] Assignee: Sahlin Engineering Company, Inc., 3m?! illiill'liflfi ffil filk r.WQFE?! Troy, Mich. Att0rney-Harness, Dickey and Pierce 22 Filed: May 27, 1971 [57] g pp 147,367 There is herein disclosed a lift control system for a press unloader having an extendable and retractable [52] U S CI 214/1 BD 214/1 BB jaw means for gripping and removing a part from the [51] 6 23/00 die cavity of a press with pivotal frame means support g the j means for pivotal movement to lift the p [58] Field of Search ..214/1 B, 1 BS, 1 EV, from the di cavity and interconnected air 0 erated 214/1 BD 147T 188 p power cylinder means to sequentially extend the jaw means, grip the part, lift the part, and retract the jaw [56] References Cited means.

7 Claims, 3 Drawing Figures LIFT CONTROL SYSTEM FOR PRESS UNLOADER OR THE LIKE BACKGROUND AND SUMMARY OF THE- INVENTION While the concept and principles of the present invention may be applicable to various types of apparatus and environments, the invention disclosed herein relates generally to press unloading apparatus and, more particularly, to press unloading devices of the type disclosed in US. Pat. Nos. 2,609,776 and 3,206,040 and to control systems therefor of the type disclosed in US. Pat. Nos. 3,474,825; 3,436,186; and 3,394,650.

It is the primary object of the present invention to provide new and improved means for lifting a formed part out of a die cavity in a press prior to removal of the part from the press cavity. To this end, a new and improved air operated control system has been devised in which the number of parts required to achieve the desired results has been reduced, the parts of the system have been arranged in a new and improved manner facilitating assembly, operation, and repair, and new and improved parts have been devised for the system.

In the presently preferred embodiment of the inventive concepts and principles, a first air operated power cylinder means actuates jaw means carried by the press unloader device between an extended part gripping position in the press cavity and a retracted position while a second air operated power cylinder means moves the jaw means between the extended part gripping position and a lift position prior to return movement of the jaw means to the retracted position. The second cylinder means is connected to high pressure air inlet hoses and exhaust hoses in series with thefirst cylinder means and providedwith integral control means effecting a time delay of operative connection to the jaw means whereby the desired sequential operation of the apparatus is obtained. It is contemplated that the inventive concepts are also applicable to fluid operated power cylinder apparatus generally whenever a time delay operation is required. Thus, in the broadest aspects of the invention, the power cylinder apparatus may be air operated or hydraulically operated and associated with any kind of machinery, particularly material handling equipment.

BRIEF DESCRIPTION OF THE DRAWING The presently preferred embodiment is illustrated in the accompanying drawing wherein:

FIG. 1 is a side elevational view of a portion of a press unloading device incorporating the inventive concepts and principles;

FIG. 2 is an enlarged cross-sectional view of a portion of the apparatus of FIG. 1; and

FIG. 3 is another enlarged cross-sectional view of a portion of the apparatus of FIG. 2 in a different operational position.

DETAILED DESCRIPTION Referring now to FIG. 1, the bottom portion of a conventional swinging arm type press unloader is shown to comprise a swingable support arm 10, a fixed support frame means 12, adjustably connected to and carried by the support arm, a movable support frame means 14 pivotally mounted on the fixed support frame, an air operated power cylinder means 16 pivotally mounted on the fixed support frame 12 and pivotally operably connected to the movable support frame 14, and a part gripping unit 18 carried by the movable support frame.

The part gripping unit 18 comprises jaw means 20 movable between a retracted position, as shown by the solid lines of FIG. 1, and an extended part gripping position, shown in phantom at 20a and 20b, by an air operated power cylinder means 22. The jaw means is also movable between an open release position, as shown by the solid lines of FIG. 1 and a closed part gripping position as shown at 20a and 20b. The movable support frame 14 and unit 18 are pivotally movable between the extended part gripping position 20a and a lift position as shown at 20b to enable the part 24 to be lifted clear of the die cavity in the press.

Referring now to FIGS. 2 and 3, the air operated power cylinder means 16 comprises a cylindrical member 30 having pivotal connecting means in the form of spaced

opposite end plates

31, 32 and tie plates 33, 34 secured by suitable fastening means 35. The cylinder is pivotally mounted on fixed support frame 12 by bearing members 36, 37 rotatably mounted in

support arms

38, 39 fixed to plate 12 and threadably mounted in cylinder end plate 32 at the bottom of the power cylinder. The cylinder 16 is operatively connected to the movable frame means 14 by a movable piston rod 40 and pivotal connecting means in the form of a bearing sleeve 42 and a bearing shaft 44 pivotally mounted in

arm portions

46, 47 fixed on the movable frame. A conventional high pressure air source 48 is connected to the power cylinder 16 through conventional control valve means 49 by air hose means 50, 52 and to the power cylinder 22 by air hose means 54, 56. 'Air hose 52 is attached to the pivotally mounted bearing member 37 by a conventional threaded coupling (not shown) mounted in a threaded portion 57 of a central air passage 58 so as to be pivotally movable therewith and air hose50 is similarly attached to the pivotally mounted bearing shaft 44 by a threaded portion 59 of a central air passage 60. Air passage 58 is connected to one side 61 of the cylinder through air passage means comprising a chamber 62, an annular inlet passage 64, a valve chamber 66, and an inlet passage 68. Chamber 62 is also connected to the same side of the cylinder through an air outlet passage and a valve chamber 72. An adjustable needle valve 74 is threadably adjustably mounted in bearing member 36 and valve chamber 66 to regulate the rate of flow of inlet air through passage 68 and thus control the rate of movement of piston rod 40 as will be hereinafter described. A spring loaded ball type check valve 76 is mounted in valve chamber 72 to prevent passage of inlet air and permit passage of exhaust air. Air passage 60 is connected to the other side 80 of the power cylinder by air passage means comprising reduced diameter passage 82, a valve chamber 84, a transverse passage 86, an annular chamber 88, axially extending passage portions 90, 92 in the piston rod 40, and a transverse outlet passage 94. Passage 60 is also connected to the same side of the power cylinder through passage 82, valve chamber 96, annular chamber 88, and

passages

90, 92, 94. An adjustable needle valve 97 is adjustably threadably mounted in bearing member 44 and valve chamber 84 to regulate the flow of high pressure air through inlet passage 86 and a spring loaded ball type check valve 98 is mounted in valve chamber 96 to prevent passage of inlet air while permitting passage of exhaust air.

The piston rod means 40 includes a tubular portion 100 slidably supported in suitably sealed bearing means 101 in end plate 32 and a reduced diameter member 102 having axially spaced

abutment flanges

103, 104 providing piston connecting means located at opposite ends of a slide rod portion 106. A piston means 108, comprising a bearing sleeve 1 10, a disc 1 l2, and sealing means 114, 116, is slidably mounted on the slide rod for movement between the

abutment flanges

103, 104 to provide timing means to prevent movement of the piston rod 40 until after the jaw means have been properly positioned.

A spring loaded relief valve 118 is mounted in end plate 31 and extends into a chamber 122 which receives piston rod flange 103 in an uppermost position, FIG. 3, whereat valve 118 is positively opened to allow any air trapped in chamber portion 80 to escape through a port 126. A sea] 128 engages the flange 103 in the fully extended position to prevent any leakage of high pressure inlet air.

In operation, with the apparatus in the position shown by the solid lines of FIGS. 1 and 2, at a predetermined time valve 49 is actuated to deliver high pressure air from source 48 to one side of power cylinders 16, 22 through air lines 50, 56 while exhausting air from the other side of the cylinders through

air lines

54, 52. The high pressure air in line 56 is immediately effective to actuate power cylinder 22 to extend and then close the jaw means on the part 24 over a predetermined time interval of, for example, one or two seconds. During the jaw extension and clamping time period, some of the high pressure air in line 50 also flows through

passages

60, 82, past needle valve 97, through

passages

86, 88, 90, 92, 94 into chamber 80 wherein it acts against the adjoining surfaces and gradually moves the piston 108 from the solid line fully retracted position to an intermediate dotted line position 108a whereat the piston engages the flange abutment 104 to begin to move the piston rod 40. The air in chamber 80 also acts against the abutment flange 103 to keep the piston rod in the retracted position until the piston engages the other abutment flange and acts against the seal 128 to prevent escape of high pressure air through valve 118. The rate of air flow is adjusted by needle valve 97 so as to move the piston 108 at a rate causing engagement of the piston with the piston rod abutment flange 104 after the jaw means has been extended and closed. Then when the piston moves the piston rod to the solid line fully extended position 108b, FIG. 3, the bearing housing 42, bearing shaft 44, support

arms

46, 47, and the movable support frame 14 are moved downwardly about pivot means 136, FIG. 1, from the normal position parallel to the fixed plate 12 to an inclined position 14b whereat the jaw means and part 24 are lifted clear of the die cavity.

Then the high pressure air source 48 is connected by valve 49 to

air hoses

52, 54 while hoses 50, 56 are connected to exhaust. Again the high pressure air is immediately effective to reversely actuate power cylinder 22 to retract and then open the jaw means at a predetermined point to release the part after a predetermined time interval. During the jaw retraction and opening time period, some of the high pressure air also flows through chamber 62, passage 64, valve chamber 66, and passage 68 to chamber 61 wherein it is effective to move the piston, without the piston rod, from the fully extended solid line position 1081) of FIG. 3 to the dotted line position 1086 whereat the piston engages the flange 103 and begins to move the piston rod 40. The high pressure air in chamber 61 also acts against flange 104, which is seated on end plate 32, to hold the piston rod in the fully extended position until the piston engages the other flange 103. The rate of air flow is adjusted by needle valve 74 so as to move the piston 108 at a rate causing engagement with the abutment flange 103 after the jaw means and the part gripped thereby have clearedthe die cavity. The rate of travel of the piston may be varied to return the movable frame 14 to the parallel position at any desired time in relationship to the position of the jaw means being actuated to the fully retracted position by power cylinder 22. It will be understood that when the piston 108 moves in one direction by application of high pressure air to one side or the other, the air on the opposite side is exhausted through the ball valves 76, 98 which are opened during exhaust due to pressure differential while being maintained closed during application of the high pressure air due to the springs and a pressure balance in the system.

It is contemplated that the inventive concepts and principles herein disclosed may be variously otherwise embodied and it is intended that the appended claims cover alternative embodiments except insofar as limited by the prior art.

I claim:

1. A control system for a press unloader having a movable arm carrying jaw means movable between a retracted position and an extended position for gripping a part in a die cavity and for carrying the part away from the die cavity, comprising air operated jaw operating power cylinder means for moving the jaw means between the extended position and the retracted position, frame means pivotally supporting said jaw operat ing power cylinder means and said jaw means, air operated frame operating power cylinder means for pivotally moving said frame means jaw operating power cylinder means and said jaw means between a part gripping position and a part lifting position whereby a gripped part is lifted from a die cavity in a press with which the press unloader is associated, timing means integral with said air operated frame operating power cylinder means to cause the pivotal movement after the jaw means has been extended and the part gripped, a pair of high pressure air hose means connected to said air operated jaw operating power cylinder means and said air operated frame operating power cylinder means to deliver high pressure air thereto and to exhaust air therefrom, said air operated jaw operating power cylinder means and said air operated frame operating power cylinder means being connected in series, first and second pivotal connecting means between said air operated frame operating power cylinder means and said frame means, one of said. air hose means being connected to said power cylinder means through one of said pivotal connecting means, and the other of said air hose means being connected to said power cylinder means through the other of said pivotal connecting means.

2. A control system for a press unloader having a movable arm carrying jaw means movable between a retracted position and an extended position for gripping a part in a die cavity and for carrying the part away from the die cavity, comprising air operated jaw operating power cylinder means for moving the jaw means between the extended position and the retracted position, frame means pivotally supporting said jaw operating power cylinder means and said jaw means, air operated frame operating power cylinder means for pivotally moving said frame means jaw operating power cylinder means and said jaw means between a part gripping position and a part lifting position whereby a gripped part is lifted from a die cavity in a press with which the press unloader is associated, timing means integral with said air operated frame operating power cylinder means to cause the pivotal movement after the jaw means has been extended and the part gripped, an air cylinder having spaced end walls, piston means in said air cylinder movable therein by air pressure during and after movement of said jaw means to the extended position, piston rod means operable by said piston and operably associated with said frame means to cause pivotal movement thereof, and connecting means operable after the movement of said jaw means to the extended position to connect said piston means and said piston rod means to said frame means to cause pivotal movement thereof, said piston means being slidably supported on and movable relative to said piston rod means during the first portion of the piston movement, said piston means being movable relative to said piston rod means during movement of said jaw means to the extended position, and said connecting means connecting said piston means to said piston rod means after the movement of said jaw means to the extended position during the last portion of the movement of said piston means.

3. The invention as defined in claim 2 and there being air flow rate adjustment means to control the rate of movement of said piston means by controlling the rate of flowof air to enable said jaw means to reach the extended position before said connecting means is effective to connect said piston means to said piston rod means.

4. The invention as defined in claim 3 and wherein said connecting means comprising spaced abutment flanges on said piston rod means engageable with said piston means after sliding movement of said piston means therebetween.

5. The invention as defined in claim 4 and wherein said spaced abutment flanges alternately engaging opposite ones of said spaced end walls of said air cylinder and being held thereagainst by high pressure air until said piston means engages one of said abutment flanges and moves said rod means.

6. A control system for a press unloader having a movable arm carrying jaw means movable between a retracted position and an extended position for gripping a part in a die cavity and for carrying the part away from the die cavity, comprising air operated jaw operating power cylinder means for moving the jaw means between the extended position and the retracted position, frame means pivotally supporting said jaw operating power cylinder means and said jaw means, air operated frame operating power cylinder means for pivotally moving said frame means jaw operating power cylinder means and said jaw means between a part gripping position and a part lifting position whereby a gripped part is lifted from a die cavity in a press with which the press unloader is associated, timing means integral with said air operated frame operating power cylinder means to cause the pivotal movement after the jaw means has been extended and the part gripped, a first frame means fixed to the movable arm, a second frame means pivoted to the first frame means and supporting said jaw means, said frame operating power cylinder means comprising an air cylinder, a movable piston, and a piston rod, a first pivotal connecting means pivotally mounting said frame operating power cylinder means between said air cylinder and said first frame means on said first frame means, a second pivotal connecting means between said piston rod and said second frame means whereby said frame operating power cylinder means is movable relative to said first frame means and said second frame means during pivotal dis placement of said second frame means, air hose means connected to said frame operating power cylinder means to supply high pressure air thereto and exhaust air therefrom, a first air hose connection integral with said first pivotal connecting means, first air passage means extending from said first :air hose connection through said first pivotal connecting means to one side of said piston, a second air hose connection integral with said second pivotal connecting means, and second air passage means extending from said second air hose through said second pivotal connecting means and said piston rod to the other side of said piston.

7. The invention as defined in claim 6 and further comprising adjustable valve means in each of said first and second passage means to variably control the rate of flow of high pressure air to said air cylinder.

Claims

1. A control system for a press unloader having a movable arm carrying jaw means movable between a retracted position and an extended position for gripping a part in a die cavity and for carrying the part away from the die cavity, comprising air operated jaw operating power cylinder means for moving the jaw means between the extended position and the retracted position, frame means pivotally supporting said jaw operating power cylinder means and said jaw means, air operated frame operating power cylinder means for pivotally moving said frame means jaw operating power cylinder means and said jaw means between a part gripping position and a part lifting position whereby a gripped part is lifted from a die cavity in a press with which the press unloader is associated, timing means integral with said air operated frame operating power cylinder means to cause the pivotal movement after the jaw means has been extended and the part gripped, a pair of high pressure air hose means connected to said air operated jaw operating power cylinder means and said air operated frame operating power cylinder means to deliver high pressure air thereto and to exhaust air therefrom, said air operated jaw operating power cylinder means and said air operated frame operating power cylinder means being connected in series, first and second pivotal connecting means between said air operated frame operating power cylinder means and said frame means, one of said air hose means being connected to said power cylinder means through one of said pivotal connecting means, and the other of said air hose means being connected to said power cylinder means through the other of said pivotal connecting means.

3. The invention as defined in claim 2 and there being air flow rate adjustment means to control the rate of movement of said piston means by controlling the rate of flow of air to enable said jaw means to reach the extended position before said connecting means is effective to connect said piston means to said piston rod means.

6. A control system for a press unloader having a movable arm carrying jaw means movable between a retracted position and an extended position for gripping a part in a die cavity and for carrying the part away from the die cavity, comprising air operated jaw operating power cylinder means for moving the jaw means between the extended position and the retracted position, frame means pivotally supporting said jaw operating power cylinder means and said jaw means, air operated frame operating power cylinder means for pivotally moving said frame means jaw operating power cylinder means and said jaw means between a part gripping position and a part lifting position whereby a gripped part is lifted from a die cavity in a press with which the press unloader is associated, timing means integral with said air operated frame operating power cylinder means to cause the pivotal movement after the jaw means has been extended and the part gripped, a first frame means fixed to the movable arm, a second frame means pivoted to the first frame means and supporting said jaw means, said frame operating power cylinder means comprising an air cylinder, a movable piston, and a piston rod, a first pivotal connecting means pivotally mounting said frame operating power cylinder means between said air cylinder and said first frame means on said first frame means, a second pivotal connecting means between said piston rod and said second frame means whereby said frame operating power cylinder means is movable relative to said first frame means and said second frame means during pivotal displacement of said second frame means, air hose means connected to said frame operating power cylinder means to supply high pressure air thereto and exhaust air therefrom, a first air hose connection integral with said first pivotal connecting means, first air passage means extending from said first air hose connection through said first pivotal connecting means to one side of said piston, a second air hose connection integral with said second pivotal connecting means, and second air passage means extending from said second air hose through said second pivotal connecting means and said piston rod to the other side of said piston.