Patent Publication Number: US-3874206-A

Title: Stroke-end programmer for machine tool

Description:
Cailloux 1451 Apr. 1, 1975 1 STROKE-END PROGRAMMER FOR MACHINE TOOL [75] lnventor: Paul Cailloux, La Varenne Saint-Hilaire, France [73] Assignee: Promecam Sisson-Lehmann,  
 Saint-Denis. France 1221 Filed: 11111115, 1974 1211 Appl. N0.;47s,107  
 3.165.140 1/1965 Hazel 1 1/1965 10/1973 Bridges 72/441 Primary ExaminerC. W. Lanham Assistant Examiner-Gene P. Crosby Attorney, Agent, or Firm-Michael S1 Striker [57] ABSTRACT A device is disclosed for programming the terminal portion of the operative stroke of the tool in a machine tool equipped with hydraulic driving means. The stop motion comprises essentially a discharge valve responsive to a control wedge rigid with said tool and adapted to engage a stop member of which the position is determined in succession by the various adjustable studs carried by a rotary barrel. The barrel is simply laid upon a pair of cradle-forming rollers, at least one roller being driven from the means controlling the angular position of said barrel; if desired, a plurality of similar barrels corresponding to different predetermined programmes may be provided.  
 7 Claims, 7 Drawing Figures Voth 72/389 Fff&#39;ENIEU APR 1 [9?5 SHEET 1 0f 3 DDUCIEIEIDE] EDI Hmfl. w  
 STROKE-END PROGRAMMER FOR MACHINE TOOL The present invention relates in general to devices for programming the terminal portion of the stroke of the tool in a machine tool. with a view to cause said tool to accomplish a series of strokes of different lengths during a predetermined cycle and thus perform each time a different operation or a specific work. for example a sequence offolding or bending steps or operations through different angles in the specific case ofa bending press or like machine.  
  This device is intended for equipping machine tools comprising hydraulic control means for actuating the movable tool through one or more cylinder and piston units.  
  At present. machine tools are known which comprise control means of this character and other means for stopping the machine tstop-motion devices) at the end of its operative stroke. in the form of a release or discharge valve inserted in the hydraulic circuit of said driving unit or units and adapted to be actuated by a control member rigidly connected to said movable tool. Preferably, this member consists of a wedge adapted to bear against a positioning stop member adjustable for properly actuating said valve. Thus. the assembly can be adjusted by simply changing the position of said stop member with a view to cause the tool to be stopped in a predetermined position.  
  It is clear that a system of this type is particularly advantageous in many types ofmachine tools and notably in bending presses or the like. However, the adjustment of said stop member. engaged by said control wedge. must obviously be modified each time it is desired to change the stopping position of the movable tool.  
  Under these conditions. this known arrangement is scarcely adequate for performing a series of successive different operations on a same workpiece. for instance a series of folding movement performed at different angular values on a same sheet-metal workpiece. It is therefore the essential object of this invention to provide a device capable of programming different final stroke movements of the movable tool of a machine tool during a predetermined cycle of operations. with a view to perform different successive works or operations on a same workpiece. However. this invention is also concerned with means capable of modifying very rapidly an existing programme with a view to accomplish different works or operations.  
  To this end. the present invention is directed to provide means for programming the terminal fraction of the stroke of a movable tool in a machine tool equipped with a hydraulic control system comprising a stop motion in the form of a release or discharge valve responsive to a control wedge rigid with said tool and adapted to engage a stop member of which the position is determined in succession by various adjustable rods or studs carried by a rotary barrel. this device being characterised in that said barrel is detachably laid upon a pair of rollers constituting a supporting and holding cradle. at least one of said rollers being driven from the means controlling the angular position of said barrel. the arrangement comprising a series of similar interchange able barrels corresponding to different predetermined programmes.  
  On each barrel the position of the various stop rods is adjustable beforehand in various ways in order to determine a precise programme of the limit stroke positions of the movable tool of the relevant machine during the various movements performed by said tool during a same cycle.  
  According to another feature characterising this device the barrel control system comprises a stop member. for example in the form ofa microswitch inserted in the control circuit of the relevant motor and adapted to be actuated by each stop stud when the latter has reached its predetermined working position, inasmuch as it actually projects from its barrel.  
  Under these conditions it is possible to neutralize or disengage a number of barrel rods by retracting these studs completely. Thus. in operation. the barrel continues its rotation when the retracted studs attain their theoretical operative position in which they register with the movable stop member. With this arrangement. it is thus possible to modify at will the number of programmed operations.  
  However, other features and advantages of the pres ent device will appear as the following description of a typical embodiment thereof proceeds. This description is given by way of example with reference to the attached drawings. in which:  
  FIG. 1 is a diagrammatic front elevational view of a bending press equipped with the programming device of this invention;  
  FIG. 2 is a vertical section and elevational view of the same device;  
  FIG. 3 is a section taken along the line lIl-IIl of FIG. 2:  
  FIG. 4 is an elevational view of a detail of the present device; FIGS. 5 and 6 are elevational views. i.e.. a side elevational and an end view. respectively, of a member associated with the control barrel. and  
  FIG. 7 is a fragmentary section taken along the line VllVII of FIG. 5.  
  In the example illustrated in FIG. 1 the device according to this invention is used for controlling a bending press having a fixed bending beam 1 rigid with the frame structure 2 of the machine, and a movable bending beam 3. The movements or strokes of this movable bending beam 3 are produced by means of a hydraulic cylinder and piston actuator unit 4, and a central guiding member 5 is also provided.  
  The hydraulic circuit 6 of cylinder and piston unit 4 comprises a release or discharge valve 7 constituting an integral component element of the programming device of this invention. This valve 7 comprises a control member in the form of a push-member 8 and is secured to the frame structure 2 of the machine. for example behind the movable lower beam 3.  
  This movable lower beam 3 carries an arm 9 (FIG. 2) having one end pivoted to a pivot pin 10 carried by this beam and the opposite end engaged and movable between the push-member 8 of valve 7 and a roller 11 carried by the first end of a rod 12 adapted to constitute a bearing stop member.  
  However, the upper end of arm 9 comprises a ramp or cam face 13 engageable by the roller 11. Thus, this arm 9 acts somewhat like a wedge member capable of actuating the valve 7 by reacting against the roller of stop member 12. Preferably, a blade 14 having a fixed position is interposed between the upper end of said arm or wedge 9 and said push-member 8 of valve 7 for preventing a direct frictional contact therewith during the movements of the movable tool.  
  The rod 12 extends at right angles to the axis of movement of wedge 9 and is slidably mounted in a guide bearing 15 rigid with a member 16 forming an integral part of the frame structure of the machine. However, a spring 17 attached to a fixed member 18 constantly urges the stop member 12 for engagement with the cam face 13 of wedge 9. A link 19 is also provided for guiding the corresponding end of said stop member 12.  
  At its second end opposite said roller 11 the stop member 12 carries a block 20 provided with a pin 21 for the purpose of preventing the rotation of said stop member about its axis. This block 20 registers with a rotary barrel 22 constituting the main component element of the programming device ofthis invention. This barrel 22 carries a series of screws 23 adapted to constitute as many studs projecting from the barrel end face registering with said block 20. The arrangement is such that in each angular position of said barrel only one stud thereof is adapted to act as a stop member for engagement by the block 20 when said rod 12 recedes in its bearing 15 as a consequence of the thrust exerted by the wedge 9. Thus, in the position illustrated in FIG. 2 only the lower stud 23a can act as a stop member to said block 20.  
  The position of these various barrel studs is adjust able so that they can project more or less from the front face of the barrel body. To this end. the screw end of each stud 23 has a socketed end engageable by a corresponding key 24 disposed in a waiting position on a support 25 rigid with the housing 26 enclosing the barrel 22 and the other ancillary members of the present device. said housing being of course fastened to the frame structure of the machine.  
  The barrel 22 is detachably mounted and to this end it is simply laid upon a pair of parallel rollers 27a. 27b constituting a kind of cradle. However, one of these rollers. notably roller 27b. is adapted to drive said barre l 22 for rotation about its axis by being driven in turn via an endless belt 28 from the output shaft of a motor and reduction-gear unit 29.  
  On the side opposite said block 20. the barrel 22 en&#39; gages an adjustable socket 30 so that when necessary the position of all the projecting studs 23 carried by said barrel 22 can be modified to the same extent. The socket 30 is adapted to slide in a support 3! rigid with the housing 26 and to be locked in the desired position by means of a stop screw 32.  
  The control circuit of the barrel driving motor 29 comprises a microswitch 33 of which the control member 34 is adapted to be actuated by the projecting stud 23a of said barrel, provided that this stud is in its operative position and projects sufficiently therefrom, so that it can positively stop the backward movement of said movable stop member 12. Under these conditions, the microswitch 33 is not actuated by those barrel studs 23 which are in their inoperative position.  
  The portion of the surface of block 20 which registers with the position of a stud 23a in operative position carries a plate 35 adapted to constitute a contact face. A spring 36 is interposed between this face and the block, so that the plate 35 tends to move away there from when the adjustable stop 12 resumes its normal waiting position.  
  Now the movable plate 35 comprises a member adapted to actuate a microswitch 37 each time said plate is thus released. This microswitch 37 is inserted in the control circuit of motor 29 in order to re-start same at that time.  
 The positions of the various projecting studs 23 are adjusted when each stud is in the operative position 5 23a. This constitutes an essential advantage characterising this device, for the adjustment is made when the movable tool is exactly in the position in which it is to be stopped.  
  By means of the above-mentioned key 24 the corresponding stud 23 is screwed in or out until it engages the contact plate 35 of block 20, in a position suitable for retaining the adjustment stop member 12 so that the latter acts at that time as a fixed bearing surface and the wedge 9 engages the push member 8 ofdischarge valve The same adjustment operation must be carried out for each one of the eight projecting studs 23, if it is contemplate to bend the same workpiece eight times, in succession, during each cycle. However, if a smaller number of bending steps are contemplated a proper number of projecting studs 23 must be moved to their retracted position so that only the necessary number thereof are available for the desired cycle.  
  Due to the specific mounting contemplated for the barrel 22 the device according to this invention may advantageously comprise a plurality of such barrels, all identical but adapted to carry out different predetermined programmes. Thus, each time it is only necessary to remove one of these barrels and to substitute another barrel therefor which is simply laid upon the pair of rollers 27a and 27b.  
 The device operates as follows:  
  When the movable beam 3 of the press rises as a consequence ofthe operation of the hydraulic cylinder and piston unit 4, the wedge member 9 is inserted more deeply between the push member 8 of the discharge or release valve 7 and the bearing stop 12.  
  However, this has no consequence whatsoever as long as this bearing stop 12 can recede. i.e.. until it engages the projecting stud 23a of barrel 23 which is thus in its operative position. When the contact plate 35 of block 20 engages this stud, the wedge 9 cannot move the stop member 12 further, and is thus caused to actuate the mush member 8 of valve 7, so that the control circuit of actuator 4 is exhausted and the movable beam 3 is stopped immediately.  
  Under these conditions, the movable beam 3 will be stopped exactly in the desired position for performing the bending step corresponding to a predetermined angle. After this bending step the operator may control the downward stroke of the movable beam 3, and thus the latter will move downwards bodily with the wedge 9, so that the valve 7 is re-closed. However, at the same time the contact plate 35 of block 20 resumes its inoperative position, thus closing microswitch 37 and consequently restoring the operation of motor 29 driving the barrel 22 for rotation about its axis.  
  Nevertheless, this barrel 22 is rotated only through a limited angular amplitude sufficient however for bringing another stud 23 to its operative position 230 in lieu of the preceding stud. In fact, when this other stud 23 assumes this operative position, it engages the microswitch 33 and thus the motor 29 is stopped immediately. Therefore, it is another projecting stud that will accurately determine the next ultimate position of the movable beam 3, under the same conditions as set forth hereinabove.  
  In connection with the foregoing it may be reminded that the projecting studs 23 brought to their retracted inoperative position do not actuate the microswitch control member 34, whereby in this case the barrel 22 can perform an angular movement of greater amplitude until another projecting studs is brought to the operative position.  
  The outer periphery of barrel 22 has formed therein a series of several groups of notches adapted to actuate control members 38 associated with a plurality of microswitch 39 inserted in the various circuits ofa display system according to the conventional binary code method. This display is visible on a sequence indicator mounted in a control board adapted to be installed in any desired and suitable location at some distance from the machine. and connected via a flexible cable 40 to the device.  
  Preferably. the notches (or llat faces) 41 adapted to actuate the control members of microswitches 39 are formed on the outer peripheral surface of a socket 42 fitted around the body of barrel 22. Each group of notches corresponds to one of the projecting studs 23 and. according to the specific case involved. includes one or a plurality of notches suitably disposed for producing the display contemplated according to the binary code method.  
  Ho\ve\ er. the control board may also advantageously comprise a knob for manually controlling the barrel and also another knob for preventing at will the automatic rotation of the barrel between two strokes of the mo\ able tool in order to ensure a repetition of the tool action.  
  From the foregoing it appears clearly that multivarious possibilities of use of a machine tool can be derived from this device. since. in addition to a programmed stroke end of the movable tool it also affords a repetition ofeach working pass or alternatively the performance of a partial operation by neutralising some of the barrel studs.  
  In any case. with the adjustable socket 30 it is also possible simultaneously to shift by a same value the position of the various projecting studs of barrel 22, for example to take due account ofa variation in length in a series of workpieces to be bent. or variations in the viscosity of the fluid circulating in the hydraulic circuit, or any other factors or parameters likely to entail a modification in the final result.  
  Moreover. the programmed control device of this invention may advantageously be combined with means for adjusting the non-programmed stroke end or limit.  
  These means advantageously comprise a rod 43 reg istering with the block 20 of stop member 12, and more particularly with the portion of the surface of this block which is not covered by the contact plate 35.  
  This rod 43 is screwed in a fixed support 46 and rigid with a rotary cap 44 rotatably mounted on said support. This cap 44 carries a control crank handle 45 whereby the position of said stop rod 43 can be adjusted at will. ()l&#39;course. when this manual adjustment system is operative the barrel 22 must be removed, but it is also possible to dispose all the studs 23 thereof in their retracted inoperative position.  
  conversely. when it is desired to use the programming system comprising the barrel 22, the control rod 43 must be disconnected or neutralised by retracting same to its fully inoperative position.  
  As already mentioned hereinabove, the present device is advantageous, inter alia, in that it permits of programming the terminal portion of the stroke of the movable beam ofa press as illustrated in FIG. 3 during a series of movements forming a same cycle, with a view to bend several times a same workpiece according to different, increasing angular amplitudes. However. it may also be emphasized that the same device may be used for programming different machine tools in a similar manner. Besides. it will readily occur to those conversant with the art that all machine tools equipped with the device of this invention are also covered by the present invention and fall within the scope thereof.  
 What is claimed as new is:  
  1. Device for programming the terminal portion of the stroke of the tool of a machine tool equipped with a hydraulic control system incorporating a stop-motion consisting essentially of a discharge valve. said device comprising:  
 a movable stop member comprising a first end disposed in front of said discharge valve and a second end on opposite side.  
 control wedge rigid with said tool and movable be tween said first end of said stop member and said discharge valve and adapted to actuate said valve by reacting against said first end of said stop mcmber.  
 a rotary barrel disposed in front of said second end of said stop member.  
 a plurality of parallel adjustable studs carried by said rotary barrel.  
 a pair of parallel rollers constituting a cradle for supporting said barrel laid detachably upon said rollers driving means adapted to drive at least one of said rollers, whereby said adjustable studs are brought successively in operative position in front of said stop member.  
  2. Programming device as set forth in claim 1 further comprising a series of similar interchangeable barrels corresponding to a plurality of predetermined programmes.  
  3. Programming device as set forth in claim 1. wherein said driving means. of at least one of said rollers comprise a motor and said device further comprises a first microswitch inserted in the energizing circuit of said motor and adapted to be actuated by each stud projecting from said barrel when the stud involved is in its operative position and inasmuch as it actually projects from said barrel.  
  4. Programming device as set forth in claim 3, wherein said barrel driving motor control circuit comprises a second microswitch adapted to be actuated by said movable stop member when the latter is returned to its waiting position by a return spring after each operation of the machine.  
  5. Programming device as set forth in claim 4, wherein said second end of said movable stop member which is adjacent to said barrel carries a contact plate mounted on one or a plurality of spacer springs and adapted to actuate the microswitch controlling the energization of the barrel driving motor.  
  6. Programming device as set forth in claim 5. wherein, on the side opposite to said movable stop member. said barrel bears against an adjustable socket adapted. by modifying its position, to simultaneous 7 8 change to the same extent the position of the end of all tool control system comprising an adjustable rod the Studs prolecung from Send barre&#34; adapted to be retracted completely when it is desired 7. Programming device as set forth in claim 5, further comprising a non-programmed manual system for controlling the terminal position of the movable tool. said to operate the programmed control device.