US3885165A

US3885165A - Press control switch

Info

Publication number: US3885165A
Authority: US
Inventors: Lawrence A Franks; James E Perry
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-10-05
Filing date: 1973-10-05
Publication date: 1975-05-20
Anticipated expiration: 1992-05-20
Also published as: JPS5077976A

Abstract

A press control switch comprises a rotatable tuning shaft assembly rotatably driven in positive synchronism with a machine, such as a stamping press and associated infeed and/or outfeed equipment, for processing the workpiece therethrough. A plurality of proximity pickup units are fixedly mounted adjacent the shaft assembly in radially spaced relation therefrom and are axially spaced therealong. A plurality of disk pairs are axially spaced along the shaft in radial opposition to the corresponding ones of the proximity pickups and are provided, on their oppositely and outwardly facing radial surfaces, with circumferentially extending conductive segments adjacent the disk periphery. Means are provided for circumferentially adjusting the disks of each pair relative to each other for determining the angle of shaft rotation through which each disk pair will actuate its associated proximity sensor. The shaft assembly includes one end portion bearing at least one such disk pair which is rotatably adjustable with respect to the rest of the shaft assembly and which may be positively circumferentially locked with respect thereto. The shaft assembly further includes a motion detector disk having a plurality of circumferentially spaced conductive segments thereon which coact with a further proximity sensor to monitor shaft rotation and synchronism thereof with the machine to be controlled. Triac circuitry driven by respective proximity sensors actuates corresponding control functions of the machine by which the shaft assembly is rotatably driven.

Description

United States Patent [191 Franks et al.

1 1 PRESS CONTROL SWITCH [76] Inventors: Lawrence A. Franks, 609 E.

Chicago Rd.; James E. Perry, 1401 W. Rishel Rd., both of Sturgis, Mich. 4909] 22 Filed: Oct. 5, 1973 2 1] Appl. No.: 403,848

Primary Examiner-B. Dobeck Attorney, Agent, or Firm-Woodhams, Blanchard and Flynn 1 1 ABSTRACT A press control switch comprises a rotatable tuning [111 3,885,165 1451 May 20, 1975 shaft assembly rotatably driven in positive synchronism with a machine, such as a stamping press and associated infeed and/or outfeed equipment, for processing the workpiece therethrough. A plurality of proximity pickup units are fixedly mounted adjacent the shaft assembly in radially spaced relation therefrom and are axially spaced therealong. A plurality of disk pairs are axially spaced along the shaft in radial opposition to the corresponding ones of the proximity pickups and are provided, on their oppositely and outwardly facing radial surfaces, with circumferentially extending conductive segments adjacent the disk periphery. Means are provided for circumferentially adjusting the disks of each pair relative to each other for determining the angle of shaft rotation through which each disk pair will actuate its associated proximity sensor. The shaft assembly includes one end portion bearing at least one such disk pair which is rotatably adjustable with respect to the rest of the shaft assem bly and which may be positively circumferentially locked with respect thereto. The shaft assembly further includes a motion detector disk having a plurality of circumferentially spaced conductive segments thereon which coact with a further proximity sensor to monitor shaft rotation and synchronism thereof with the machine to be controlled. Triac circuitry driven by respective proximity sensors actuates corresponding control functions of the machine by which the shaft assembly is rotatably driven.

12 Claims, 9 Drawing Figures 5 lb mass ,165 PATENTEDHAYZOISYS 3.885

SHEET 1 BF 2 PATENTEU SHEET 2 UP 2 OPTICALLY COUPLED ISOLATION PRESS CONTPOL SOLENOXD PRESS CONTROL SWITCH FIELD OF THE INVENTION This invention relates to a multifunction machine control switch and more particularly relates to a muitifunction switch apparatus employing a rotatable shaft assembly synchronously driven by a machine, such as a stamping press, to be controlled.

BACKGROUND OF THE INVENTION The present invention was developed for control of a stamping press and, for convenient reference, will be discussed in such context. However, use of the present invention in other multifunction control applications is contemplated, particularly in multifunction machine control.

Control of multifunction production machinery, such as stamping presses, has long posed a problem in the art.

Stamping presses, for example, require accurate timed control and synchronism of plural functions such as workpiece infeed, location of the top of the press ram stroke, amount of press rarn overshoot, workpiece strip length cut off and removal of scrap from the die. One or more of these functions may require its timing to be varied with respect to other functions, in relation to increases or decreases in the set operating speed of the press. The timing of various of these functions may require variation when dies or workpiece material are changed, as when the press is converted from produc tion of one product to production of another.

In addition, such multifunction controls face a difficult operating environment, being subjected to significant and repetitive mechanical shock in operation of the machine e.g. stamping press, controlled thereby as well to contamination and damage by grease, dirt, metal particles and so forth. Such controls should provide precise timing of machine functions, despite substantial variations in the operating speed of the machine and should be capable of rapid, simple adjustment particularly where frequent variation of relative timing between the functions is required, as well as where the time duration of given functions relative to the machine power input shaft speed is required.

One prior control for stamping presses included conductive drums on a shaft rotatable with the press input shaft and engageable with conductive brushes. One disadvantage of such arrangement is that environmental residues, dirt and the like accumulate on the brushes and/or drums within a short time, making the apparatus unreliable and requiring frequent and careful cleaning.

Another prior press control used cams on a shaft rotatable with the press drive shaft, wherein the cams actuate mechanical switches. Disadvantages of such prior arrangement include the accumulation of dirt and other environmental residues on the contacts and/or cams and switches. In addition, the switch contacts, and when used, intervening rocker arms between the switches and cams tend to float particularly at higher press speeds.

Thus, such prior devices have been less than satisfactory for use as press controls.

Accordingly, the objects of this invention include provision of:

l. A multifunction machine control switch apparatus capable of controlling, and maintaining synchronism between, a plurality of operative portions of a production machine, particularly of a stamping press, and capable of maintaining synchronism between such portions and the input drive shaft of such machine.

2. Apparatus, as aforesaid, capable of maintaining proper machine operation over a wide range of operating speeds thereof.

3. Apparatus, as aforesaid, wherein the duration and start and stop times relative to machine input drive shaft rotation, of a plurality of functions can be rapidly and simply adjusted.

4. Apparatus, as aforesaid, wherein provision is made for rapid and simple adjustment of one group of control devices with respect to a remaining group of control devices in an independent manner.

5. Apparatus, as aforesaid, which provides reliable and accurate electrical control of machine operation over long periods of use in a hostile atmosphere and environment and which is relatively uneffected by accumulation of dirt, grease, and other contaminants on operating parts thereof.

6. Apparatus, as aforesaid, which is free of moving mechanical switching contacts and is not subject to mechanical float or bounce of switch elements, particularly at higher press speeds.

7. Apparatus, as aforesaid, which includes means for monitoring the rotational speed of such elements and of the rotatable press input shaft driving same.

8. Apparatus, as aforesaid, readily usable with new or existing machines.

9. Apparatus, as aforesaid, which is relatively simple in construction and manufacturable at relatively low cost, which is capable of a relatively long and troublefree operating life under adverse conditions with little or no maintenance, and which is readily maintainable.

10. Apparatus, as aforesaid, which provides for substantial interchangability and standardization of parts therein, so as to minimize maintenance and inventory size.

Other objects and purposes of this invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspecting the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of apparatus embodying the present invention, partially in diagrammatic form and, for clarity, omitting wiring between electrical components.

FIG. 2 is a fragmentary sectional view substantially taken on the line Il-II of FIG. 1.

FIG. 3 is an enlarged, partially broken sectional view substantially taken on the line III-III of FIG. 1.

FIG. 4 is an enlarged fragmentary sectional view substantially taken on line IV-IV of FIG. 1.

FIG. 5 is an enlarged sectional view substantially taken on the line VV of FIG. 1.

FIG. 6 is an enlarged sectional view substantially taken on the line VIVI of FIG. 1.

FIG. 7 is an enlarged sectional view substantially taken on the line VII-VII of FIG. 1 and additionally disclosing, in schematic form, circuitry associated with a speed detection portion of the apparatus.

FIG. 8 is an enlarged sectional view substantially taken on the line VIIIVIII of FIG. 1.

FIG. 9 is a diagrammatic view disclosing a typical portion of the electrical circuitry associated with the apparatus of FIG. 1.

Certain terminology will be used in the following de scription for convenience in reference only and will not be limiting. The words. up", down". right" and *left will designate directions in the drawings to which reference is made. The words front" and rear" will refer to the leftward and rightward portions of the ap paratus as shown in FIG. 2. The words *in" and out will refer to directions toward and away from, respectively, the geometric center of the device and desig nated parts thereof. Such terminology will include derivatives and words of similar import.

SUMMARY OF THE INVENTION The objects and purposes of the invention are met by providing a press control switch which comprises a ro tatable tuning shaft assembly rotatably driven in posi tive synchronism with a machine, such as a stamping press and associated infeed and/or outfeed equipment, for processing the workpiece therethrough. A plurality of proximity pickup units are fixedly mounted adjacent the shaft assembly in radially spaced relation therefrom and are axially spaced therealong. A plurality of disk pairs are axially spaced along the shaft in radial opposition to the corresponding ones of the proximity pickups and are provided, on their oppositely and outwardly facing radial surfaces, with circumferentially extending conductive segments adjacent the disk periphery. Means are provided for circumferentially adjusting the disks of each pair relative to each other for determining the angle shaft rotation through which each disk pair will actuate its associated proximity sensor. The shaft assembly includes one end portion hearing at least one such disk pair which is rotatably adjustable with respect to the rest of the shaft assembly and which may be positively circumferentially locked with respect thereto. The shaft assembly further includes a motion detector disk having a plurality of curcumferentially spaced conductive segments thereon which coact with a further proximity sensor to monitor shaft rotation and synchronism thereof with the machine to be controlled. Triac circuitry driven by respective proximity sensors actuates corresponding control functions of the machine by which the shaft assembly is rotatably driven.

DETAILED DESCRIPTION The apparatus 10 (FIG. 1) embodying the invention includes a generally rectangular housing 11. The housing backwall 12 here carries mounting bosses 13 (FIG. 2) for bearing against a wall 14 of a multifunction machine. such as a press, to be controlled. The housing backwall 12 is normally fixed to the press wall 14 by any convenient means, such as machine screws not shown. In FIG. 1, for convenience, the press 16 is diagrammatically disclosed in substantially reduced size, block form. The housing 12 further includes

end walls

18 and 19 and top and

bottom walls

21 and 22 which project forwardly from backwall 12. A cover 23 (FIG. 2) is hinged at 24 on the top wall 21. A catch 26 on the bottom wall 22 holds the cover closed over the open forward (leftward in FIG. 2) face of the housing 11.

The housing 11 may be of any convenient construction but is preferrably a metal casting, such as of aluminum. A horizontal shelf 28 extends forwardly from the backwall 12 part way to the front face of the housing and is located substantially centrally between the top and bottom housing walls. The shelf 28 is interrupted intermediate its ends. as shown in FIG. 1, to allow wired connections to portions of the press not shown, as well as to allow entry of electric power supply lines into the housing 11.

A rotatable timing shaft assembly 34 (FIGS. 1 and 4) extends horizontally across the housing 11 between the shelf 28 and bottom wall 22 and through end walls I8 and 19. The shaft assembly 34 includes a main shaft 36, which extends the full length of the shaft assembly, and a hollow adjustable shaft 37 (FIG. 4) telescoped over the leftward end portion of the main shaft 36 as hereafter described.

The main shaft 36 is preferably of cold rolled steel and the hollow adjustable shaft 37 is preferably of bearing bronze.

Bearing units 39 and 46 (FIG. I) support the ends of the shaft assembly 34 and, more particularly. opposite end portions of the adjustable shaft 37 and main shaft 36, respectively. The bearing

units

39 and 40 are preferably mirror images of each other and a description of bearing unit 40 (FIG. 3) will suffice for both. Bearing unit 40 includes a substantially platelike, rectangular retainer 42 snugly received in a forwardly opening, substantially rectangular notch 43 in the forward edge of corresponding housing end wall 19. Opposed hemicir cular depressions 46 and 47 in the opposed ends of the retainer 42 and notch 43 snugly receive a bearing 48, here a ball hearing. A pair of cap screws 49 secure the retainer 42 in notch 43 to fixedly mount the bearing in the corresponding housing end wall. Thrust rings 51 (FIG. 4) on the bearings 48 positively prevent axial outward movement of the bearings with respect to the

housing walls

18 and 19.

The main shaft 36 (FIG. 4) comprises a series of portions distributed axially therealong as follows. The main shaft 36 includes, near the rightward end thereof. a cylindrical journal 53 snugly supported for rotation within the bearing 48. A reduced diameter driven portion 54 extends rightwardly out of the housing 11 and has a keyway 55. Immediately inboard of the journal 53 is an enlarged diameter support portion 57 including threaded

end parts

58 and 59 and an elongate interme diate part 61 having a keyway, or slot, 62 extending axially therealong. The remaining. leftward portion of main shaft 36 comprises an elongate minimum diameter portion 64 which integrally couples to the support portion 57 through a short, intermediate diameter journal 66. A nut 60 is secured on the threaded portion 58 of the main shaft and preferably prevented against movement with respect thereto, as by silver soldering or the like. Altematively, the nut 60 may be integral with the main shaft.

The hollow adjustable shaft 37 is telescoped over the portion 64 and journal 66 of the main shaft and is internally stepped to snugly but rotatably bear on the journal 66 and an intermediate part of the minimum diameter end portion 64 of the main shaft. The hollow adjustable shaft 37 is journalled at. 68 in the bearing 48 in radial opposition to the leftward radial bearing contact between the main and holiow shaft. The hollow shaft 37 has a reduced diameter, clutch support end portion 69 extending outboard of the bearing 48, which has a keyway 71. The hollow shaft 37 further includes an enlarged diameter support portion 73 which is threaded at 74 adjacent the bearing 48. A keyway, or slot, 75 intermediate the ends of support portion 73 terminates at the rightward end of the hollow shaft 37 in a radially extending, nut-like head 76. The head 76 axially abuts the leftward end of main shaft support portion 57 and- /or the opposed radial face of nut 60. Such abutment and radial abutment of the threaded portions 59 and 74 with the adjacent bearings 48 holds the

shafts

36 and 37 in axially assembled condition.

A releasable, positive clutch unit 79 (FIG. 4) normally provides a driving connection between the leftward ends of

shafts

36 and 37. The clutch unit 79 includes an adjustment knob 80 axially slideable on the leftward end 69 of main shaft 37 and keyed thereto at 81. The leftward, outboard face of knob 80 is recessed at 82 for housing an internally toothed ring gear 83, se cured to the knob 80 by axial screws 84. An externally toothed spur gear 86 is received in recess 82 normally drivingly engages the teeth of ring gear 83. The spur gear 86 is fixed to the extended leftward end 64 of main shaft 36, as by a roll pin 87 and/or set screw 88.

The adjustment knob 80 is normally retained in engaged position, shown in solid lines in FIG. 4, shown by frictional engagement with the hollow shaft 37, key means 81 and spur gear 86. However, if desired, resilient biasing means of any convenient kind can be employed to resiliently urge the adjustment knob 80 leftwardly. The adjustment knob 80 is shiftable rightwardly to the dotted line position 80A for disengaging spur gear 86 and thereby allowing relative rotational adjustment between hollow shaft 37 and main shaft 36.

A positive drive connection is established between the main press drive shaft S (FIG. 1) and the rightward end 54 of main shaft 36, as by conventional chain drive, schematically indicated at 89, to a sprocket 90 keyed to the shaft end 54. The press drive shaft in turn is conventionally driven from a suitable motive power source M, conveniently an AC powered electric motor.

The shaft assembly further includes a plurality of disk units 91 through 97 and 101. The disk units 91 through 97 are preferably identical and a description of one will suffice for all. Thus, the disk unit 95, for example, comprises a face-to-face abutting pair of relatively rotatably adjustaable disks 104. The disks 104 are preferably identical. The disks are of insulative material, here of fiberglass impregnated with a synthetic resin material. Each disk 104 includes a semicircular (here of l80extent) printed conductive layer 106 spaced from center of such disk and extending to the periphery thereof. The conductive layer 106 is preferably applied by printed circuit board construction techniques. A central opening 107 in each disk enables snug but relatively rotatable reception of the portion 57 of main shaft 36, or portion 73 of hollow shaft 37, therethrough. The disks 104 of each pair are normally arranged in back-to-back abutting relation with the conductive portions 106 thereof facing axially outwardly of the pair.

The disks are of each pair are relatively rotatably adjustable to maximize or minimize the circumferential overlap of the conductive portions 106 thereof. Thus, as seen in FIG. 6, the conductive portion 106 of a disk 104 can be overlapped with the corresponding conductive portion 106A of its mate. Such overlap can range from a full overlap to a non-overlapped condition, to provide, in the preferred embodiment shown, conductive material in l80 to 360 of the circumference of the disk pair.

The motion detector disk 101 (FIG. 7) differs from disk units 91 through 97 in that it comprises only a single disk and is provided with a plurality of circumferentially short, spaced conductive layer portions 109. The motion detection disk 101 is otherwise similar to the disks 104.

Several disk units, here for example disk units 91 through 95, are spaced along the support portion 57 of main shaft 36 by intervening hollow cylindrical spacers 112 (FIGS. 1 and 4). The axial lengths of the spacers 112 is selected to maintain the desired spacing between adjacent disk units. The spacers 112 snugly, but axially slideably, surround the shaft portion 57. Means (here set screws 113), secured to each of the spacers 112, engage in the slot 62 to prevent rotation of the spacer 112 on the shaft, while allowing free axial movement of the spacer on the shaft. Shorter spacer rings 115, similar to the spacers 112 but without the set screws 113, are located axially outboard of the end disk pairs 91 and 95. The spacers 112 and spacer rings 115 are preferably of nylon. A resilient wave washer 117, a nut 118 and lock nut 119 (FIG. 4) are provided on the threaded portion 59 of main shaft 36 in that sequence. The wave washer 117 bears against the adjacent spacer ring 115, the latter preferably overlapping somewhat the threaded shaft part 59. Upon tightening of

nuts

118 and 119, the resultant assembly of disk units 91 through 95, spacers 112 and spacer rings 115 is snugly axially pressed together between the wave washed 117 and the nut 60 fixed to the main shaft 36. Such accurately axially locates the disk pairs on the shaft 36. Also, frictional engagement between disks of each pair and between the disk pairs and adjacent abutting spacers and/or spacer rings circumferentially fixes the disks of each pair with respect to each other, with respect to the other disk pairs on the main shaft and with respect to the main shaft itself.

The remaining disk pairs 96 and 97 and the motion detector disk 101 are located on the hollow shaft 37 in a similar manner by further and corresponding spacers 112', spacer rings 115', wave washer 117', nut 118 and lock nut 119'. Thus, the disk pairs 96 and 97 and motion detector disk 101, with their corresponding spacers 112' and rings 115', are disposed on the portion 73 of hollow shaft 37 and are snugly sandwiched thereon between the head 76 and the locking assembly comprising washer 117' and nuts 118' and 119', the nuts threadedly engaging the threaded portion 74 of the hollow shaft. If desired, the motion detector disk 101 may be disposed instead on the main shaft in addition to or in replacement of one of the disk pairs 91 through 95.

Distributed along the forward edge of the shelf are a plurality of channel or U-shaped pickup mounting brackets, preferably aluminum extrusions, one thereof being indicated at 122 (FIGS. 1, 2 and 5). The mounting bracket 122 includes a bight wall 124 secured by cap screws 125 to the forward edge of the shelf 28. The brackets 122 depend from the front shelf edge substan tially over the axis of the shaft assembly 34 and in axially centered relation between an adjacent pair of disk units, here

disk units

91 and 92.

A generally U-shaped proximity pickup 127 is carried on the outboard face of each of the forwardly extending legs 129 of the bracket 122 and is secured thereto, for example by screws 130 threadedly engaging the correspopnding leg 129. The pickups 127 are each centered over a corresponding disk pair and are provided with a downwardly opening slot 131 (FIG. 1) extending transversely therethrough for loosely and freely rotatably receiving the conductive peripheral portions 106 of the corresponding disk pair in overlapping relation. In the particular embodiment shown, the proximity pickups are the type manufactured by Electronic Counters and Controls. Inc. of Mundelein, Illinois and are arranged to sense the presence or absence of metal in the slot 131 thereof.

When an odd number (three or more) of disk units are provided in close spaced relation (for

example disk units

93, 94 and 95, in FIG. 1) the pickup mounting bracket for the odd disk unit (for example disk unit 93) may be modified, if desired, to eliminate the unnecessary mounting bracket leg, as for example at 122'.

The housing 11 includes a pair of longitudinally extending bosses 132 and 133 (FIG. 2) above the shelf 28. A circuitry mounting plate 134 extends substantially the width of the housing above the shelf 28 and is fixed to the bosses 132 and 133 as by screws 136 (FIGS. 1 and 2). The mounting plate 134 carries a regulated DC power supply 140 at its rightward end and a plurality of paired triac units 142 at its leftward end. In the prefered embodiment shown, the triac units 142 are preferably of the type manufactured by Texas In struments, Inc. of Dallas, Texas, each unit providing a pair of optically coupled triac circuits as schematically indicated in FIG. 9, there being one such track circuit 143 for each operating disk pair. In the particular em bodiment shown, three paired units 142 provide six triac circuits 143 and such are connected by cabling not shown in the proximity pickups of the disk pairs 92 through 97. Disk pair 91 is here provided as a spare should additional machine functions require control in any particular instance. Sufficient space is provided on the mounting plate for additional triac units.

The interconnection of the pickups 127, triac circuits and the power supply 140 is schematically illustrated with respect to one such pickup unit in FIG. 9, the con nections for the remaining pickup units being similar.

The power supply 140 includes a step down transformer 145 driven from the switchable AC source, shown, through a fuse 146. The secondary winding 147 of the transformer has a grounded center tap 148. A pair of rectifying diodes 151 and 152 couple the ends of secondary 147 to a conventional filter and regulator circuit 150. The output of the filter and rectifier circuit 154 is applied to an input of each of the pickups 127. The DC output of filter-regulator unit 154 may also be used as indicated to provide DC operating potentials for circuitry (FIG. 7) associated with the motion sensing pickup. The output of each pickup 127 is applied to the corresponding triac circuit, here through a conventional optically coupled isolation device 156 and trigger circuit 157, to the gate of a triac 158. Each triac, in turn, controls current flow through a corresponding one of plurality of conventional press control solenoids 159, each associated with a preselected and conventional press, press infeed or press outfeed operating device not shown.

In the embodiment shown, disk pair 92 controls a conventional air blow off device for blowing scrap workpiece material out of the press dies, disk pair 93 operates a press cut off device controlling outgoing workpiece strip cut off (and hence the length of the completed workpiece) and is also useable to control the height of a stack of finished workpieces. Disk pairs 94 and correspondingly control workpiece infeed.

On the other hand, disk pairs 96 and 97 mounted on the adjustable shaft 37 respectively control the timing of the top stop of the press (stopping of the press with the die open) and the overshoot of the press ram. Both such parameters are variable with speed of operation of the press. as a result of differences in ram momentum at different speeds and in view of the response time for hydraulic valves utilized to provide operating fluid for driving the ramv Reference may be made to US. Pat. No. 3 4lO I30, assigned to the assignee of the present invention for discussion of a press and workpiece feeding means with which the present invention can be used.

As schematically indicated in FIG. 7, output from the proximity sensors 127 of the motion detection disk 10] is applied to circuitry 162. Circuitry 162 includes, in series, an amplifier 163 driving an RC threshold network 164. The output of the latter is applied through a further amplifier 170 to the operating coil 171 of a relay having a contact 172 in the main AC power sup ply for the press. Threshold circuit 164 includes a resis tance 165 coupling amplifiers 163 and 170, and a parallel capacitor 166 and variable resistor 167 coupling the input of amplifier 170 to power supply ground. Operating potential is supplied the amplifiers 163 and 170 from the filtered and regulated output 154 of supply of FIG. 9, in any conventional manner not shown. Opening of contact 172 turns off the press when the rotational speed of the shaft assembly 34 falls below a preselected minimum speed, indicating a failure in the positive drive connection between shaft assembly 34 and the press drive shaft.

Basically then, if the shaft assembly 34, and therewith motion detector disk 101, are rotatably driven, the corresponding proximity pickup 127 provides a pulsed output, corresponding to passage of the conductive segments 109 thereof through pickup slot 131, to amplifier 163, and thence through resistor to charge capacitor 166. Adjustable resistor 167 provides a constant resistance discharge path for capacitor 166 and, depending on the adjustment thereof, limits the input voltage supplied by capacitor 166 to amplifier 170. When the speed of shaft assembly 34 is above the threshold established by resistor 167 (e.g. corresponding to a press drive shaft speed minimum between for example 20 to 50 rpm), amplifier drives the relay coil 171 and maintains closed the switch 172 between the AC source and the press AC input, maintaining the press in operation. On the other hand, when the pulse rate from pickup 127 falls below such threshold, the charge on capacitor 166 falls, as does the corresponding output of amplifier 170, whereupon relay coil 171 is provided insufficient holding current and switch 172 opens, deenergizing the press.

OPERATION Considering the assembly of the apparatus 10, precise adjustment of the length of the shaft assembly, with respect to the width of the housing 11, can be established by placing the telescoped

shafts

36 and 37, with the bearings 48 in place on the journals S3 and 68, in the depressions 47 and retaining same therein with the retainers 42 and screws 49. Thereupon, the jam nut 60 can be threadedly adjusted on the main shaft 36 to provide the desired axial clearance, by Contact with the head 76, between the shaft portions 59 and 74 and their adjacent bearings 48. Once the desired end clearance is obtained the shaft assembly can be removed from the housing and the jam nut 60 may be silver soldered in place on main shaft 36.

Assuming proper prior location and securement of the jam nut 60 on main shaft 36, assembly of the shaft assembly 34 may proceed as follows. With the hollow shaft 37 telescoped over the leftward, or small diameter end, of the main shaft 36, with the head 76 abutting the jam nut 60, the rings 115, disk pairs 91 through 95 and spacers 112 are assembled on the main shaft 36 in the order shown in FIG. 1. The set screws 113 are adjusted radially into the slot 62 sufficiently to overlap the side wall thereof, but not to engage the bottom wall thereof, whereby the spacers 112 are capable of axial but not circumferential movement with respect to the main shaft. Thereafter, the wave washer 117, nut 118 and lock nut 119 are threaded onto the main shaft portion 59. The nut 118 is threadedly adjusted to partially compress wave washer 117 and thereby establish a resilient compressive force on the rings, disk pairs and spacers sufficient to hold same circumferentially in place dur ing normal operation. The positioning of nut 118 is locked by lock nut 119.

In a similar way, rings 115, disk pairs 96 and 97, motion detector disk 101 and spacers 112' are applied to the hollow shaft 37 and resiliently held against circumferential movement thereon by wave washer 117' and nut 118' and 119'. The bearings 48 are applied to the journals 53 and 68 and the resultant shaft assembly is then conveniently placed in the housing with bearings 48 entering the housing end wall depressions 47 and being retained by the retainers 42 and screws 49.

At this point, or immediately proceeding the previous step, the clutch unit 79 and drive sprocket 90 may be assembled on the end portions of the shaft assembly. The adjustment knob 80 of the clutch 79 is urged rightwardly (FIG. 4) over the key 81 on the exposed end of the hollow shaft 37 to its position shown. Thereafter, the spur gear 86 is placed on the extended end 64 of main shaft 36, with the external teeth thereof meshed with the internal ring gear 83 of the adjustment knob 80. Set screw 88 and pin 87 are placed to circumferentially and axially lock the spur gear on the shaft end 64. The drive sprocket 90 is placed on the rightward main shaft end 54. Preferably, a set screw not shown on the sprocket hub is tightened in engagement with the key on the shaft end 54 to secure the drive sprocket thereto.

The plate 134, with the triac units 142 and power supply 140 thereon, is secured to the housing by the screws 136. The pickup brackets 122 and 122', with the pickups 127 thereon, are secured to the shelf 28 by the screws 125, to locate the pickup slots 131 with the disk peripheries substantially centered therein. The resultant assembly can then be mounted by any convenient means, such as screws not shown, on the machine 16 to be controlled.

Triac units 142 and power supply 140 on the plate 134 are preferably prewired to each other and if desired may be prewired to the pickups 127. Electrical connections to the above components, as seen in FIG. 9, is lead through the housing opening 31 to the AC supply and to the solenoids 159 mounted in a conventional mannar other locations on the press. Access may be had to the parts shown in FIG. 1 at any time by opening the cover 23. The cover 23 is normally losed to lessen entry to foreign material into the housing.

In operation, the shaft assembly 34 is positively rotatably driven through the positive chain and

sprocket connection

89, 89' and 90 from the main press drive shaft S in turn driven by motor M in any conventional manner. A one-to-one drive ratio is preferably maintained between shaft assembly 34 and press main shaft S.

The shaft assembly 34 thus rotates in positive synchronism with the press drive shaft S. As indicated, the press 16 may for example be a punch press of the type disclosed in aforementioned US. Pat. No. 3 4l0 I30 and wherein the press drive shaft 5 controls the operation of a moveable press ram, providing for opening and closing of a motion of opposed punching dies, as well as associated workpiece feed and cut off devices. Indeed, the present invention may be considered an improvement on the aforementioned patent, providing timing control of, for example, step feedin of a workpiece blank to the punch press and cut-off of the punched workpiece.

The particular functions to which the disk pairs 91 through 97 and motion detector disk 101 may be employed, in the context of such a punch presses, has been discussed above and does not require repetition herewith.

One rotation of the shaft assembly 34 will normally correspond, as above indicated, to one complete cycle of the punch press ram. The shaft assembly 34 can be set up to cause performance of a set of press functions in a desired sequence and with desired function duration by appropriate rotational adjustment of the disks on

shafts

36 and 37. More particularly, the amount of circumferential overlap of the conductive portions 106 and 106a (FIG. 6) of each disk pair determines the duration of a given associated function of the press 16. Once the duration of a given function has been set by relative rotation of the disks of a corresponding disk pair, rotation of the entire disk pair on the corresponding

shaft

36, 37 determines the time at which the function will start and stop in a given cycle of press operation and relative to other press functions controlled.

Such duration and start-stop time adjustments are carried out by loosening of the

nuts

118, 119 and 118' and 119 to lessen the axial pressure, and friction, which normally maintains a given rotational setting of each of the disks with respect to the shaft assembly. The disks and disk pairs are then individually rotatably adjusted. Thereafter, such nuts are again tightened to restore proper frictional engagement.

it is contemplated that, in certain instances, it may be desirable to provide wave washers 117, 117' which upon selected tightening of such nuts will maintain circumferential positioning of the disks on the

shafts

36 and 37 during normal operation of the apparatus, but wherein such frictional engagement is sufficiently low as to allow a hand circumferential adjustment of the disks and disk pairs on the

shafts

36 and 37, without necessity for loosening nuts 118, 118'.

Circumferential adjustment on a disk or disk pair on the shaft does not disturb the existing circumferential location of adjacent disk pairs, because the intervening spacers 112 are prevented from circumferential movement by engagement of the set screws 113 with corresponding slots in the

shafts

36 and 37.

In some instances variation of operating conditions of the machine being controlled will require adjustment of timing of one set of functions with respect to timing of another set of functions. Thus, in the apparatus shown. a change of press speed will vary the press ram conditions controllable by disk pairs 96 and 97, with respect to workpiece handling functions controlled by other disk pairs. Thus, upon such a change of speed on the press, the operator can, be rightward movement of the adjustment knob 80 to disengage the clutch 79, effect rotational adjustment of hollow shaft 37 with respect to main shaft 36. and thereby effect simultaneous circum ferential adjustment of disk pairs 96 and 97 with respect to the remaining disk pairs mounted on main shaft 36. With the required adjustment made, the ad justment knob 80 is returned leftwardly to engage the spur gear, and lock in the adjustment.

The operation of the circuitry of FIGS. 7 and 9 has been discussed above and does not require repetition at this point.

Although a preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations and modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilige is claimed are defined as follows:

1. Control switch apparatus for a multifunction machine, comprising in combination:

means defining a housing mountable on the machine to be controlled;

rotatably driveable shaft means rotatably supported on said housing;

disk means including a plurality of disk pairs on said shaft means, said disk pairs each including similar relatively circumferentially adjustable first and second slim waferlike disks of insulative material, each said disk having a coaxial flat semicircular layer of electrically conducting material on one radial face thereof and adjacent and within the periphery thereof, the total circumferential extent of such layers corresponding to their electrically effective extent and being variable by relative rotation of said disks;

proximity pickup means axially and noncontactingly adjacent the rotational path of said layers of a disk pair for sensing the total circumferential extent of said disk pair occupied by both overlapping and non-overlapping portions of said layers opposed to said pickup means;

spacer means on said shaft means and disposed between said disk pairs for determining the axial location of said disk pairs on said shaft means and frictionally preventing unintended circumferential dis placement of said disks with respect to said shaft means.

2. The apparatus of claim 1 in which said pickup means comprises a plurality of proximity pickups supported on said housing in aligned relation with said shaft means, each of said pickups having a slotted sensing portion actuable by electrically conductive material and through which the peripheral portion of the adjacent disk pair is freely but closely rotatable, said first and second disks having opposed radial friction faces in face-toface contact out to the disk-pair periphery, one said flat semicircular layer being provided on the outer radial face of each said disk of said pair. said luyers being ofsimilar circumferential extent and arranged in non-interfering relation with said friction contact faces of said disks.

3. The apparatus of claim 2 in which the disks are of resin impregnated fiberglass and the conductive layer is a printed circuit-typc layer.

4. The apparatus of claim 1 in which said shaft means includes a main shaft and a hollow shaft telescoped on a portion of said main shaft and clutchable thereto, bearings spaced on said housing and engaged by spaced journals on said main and hollow shafts respectively, abutting radially extending members respectively located on the interior end of said hollow shaft and intermediate the ends of said main shaft, axially adjustable compression means on each of said main and hollow shafts adjacent respective ones of said bearings, said spacer means comprising a plurality of spacers disposed in alternating fashion with the disk pairs of said first and second sets of said main and hollow shafts, and axially pressed between the corresponding radially extending means and axially adjustable means on said shafts.

5. The apparatus of claim 4 in which said housing includes a shelf extending transversely there-across in par allel relation with said shaft means and radially spaced therefrom, a plurality of brackets dependently mounted from a longitudinal edge 01 said shelf and in substantially radial planes of the shaft, pickup means on said brackets, each such pickup means being adapted to straddle one ol'said disk pairs for sensing orbiting of an electrically conductive portion of said disk pair thercpast.

6. The apparatus of claim 5 in which said brackets include a bight wall extending along said shelf edge to ward the axis of said shaft means and a leg extending from said shelf edge over the axis of said shaft means, said pickup being removably mounted on said leg and having a sensing slot for receiving the correspondding disk pair periphery loosclcy therein.

7. The apparatus of claim 1 in which said spacer means and disks are axially movable on said shaft means and including axially spaced abutment means at least fixable on said shaft means with a set of disk pairs and spacer means disposed in series therebetween, and resilient axial bias means on said shaft means axially inboard of said abutment means for applying a resilient axial compressive force on said disk pairs and spacer means of magnitude preventing unintended disk rotation with respect to said shaft while permitting manual circumferential adjustment of individual disks or disk pairs on said shaft without loosening said abutment means.

8. The apparatus of claim '7 in which said shaft means comprises at least one shaft member having an axial slot and said spacer means comprises a hollow spacer between and friction-ally interengageable with adjacent flanking disk pairs, said spacer including inwardly extending means circumferentially locked but axially movable in said slot of said shaft member for preventing unintended rotation of one said disk upon circumferential adjustment of a disk of the adjacent disk pair.

9. The apparatus of claim '7 in which said resilient bias means comprises an axially compressible spring and at least one said abutment means comprises a nut axially threadedly adjustable on said shaft means for setting the precompression of said spring and means actuable for locking said nut on said shaft means.

10. The apparatus of claim 1 in which said shaft means comprises a first shaft extending the length of said shaft means and an adjustable hollow shaft snugly telescoped on one end portion of said first shaft and including bearings spaced on said housing for engaging a respective journal on each of said first and hollow shafts, axially abutting means on said first and hollow shafts for positively limiting further inward axial movement of said hollow shaft on said first shaft and incorporating a nut axially threadedly adjustable on one said shaft and axially engageable means fixed on the other shaft for precisely adjusting the spacing of said journals to conform to the bearing spacing.

11. Control switch apparatus for a multifunction machine, comprising in combination:

means defining a housing mountable on the machine to be controlled;

rotatably driveable shaft means rotatably supported on said housing;

disk means including a plurality of disk pairs on said shaft means, said disk pairs each including similar first and second waferlike disks of insulative material, each said disk having a coaxial semicircular layer of electrically conducting material on one radial face thereof and adjacent the periphery thereof;

spacer means on said shaft means and disposed between said disk pairs for determining the axial location of said disk pairs on said shaft means and frictionally preventing circumferential displacement of said disks with respect to said shaft means;

said spacer means comprising hollow cylindrical spacers snugly received on and slideable axially on said shaft means, and including means preventing circumferential movement of at least selected ones of said spacers on said shaft means and further including axially adjustable compression means for releasably sandwiching together an alternating series of disk pairs and spacers on said shaft means with sufficient force as to prevent unintended relative rotation of said disks and shaft means, and preventing unintended circumferential shifting of adjacent disks, but allowing circumferential adjustment of said disks with respect to each other, with respect to adjacent disk pairs and with respect to said shaft means.

l2. Control switch apparatus for a multifunction machine, comprising in combination:

means defining a housing mountable on the machine to be controlled;

rotatably driveable shaft means rotatably supported on said housing;

said disk means further including a detection disk having a plurality of uniform and uniformly spaced conductive segments on a radial face thereof and adjacent the periphery thereof, said detection disk being carried by said shaft means for rotation therewith, pickup means fixedly mounted on the housing in overlapped close relation with the orbit ofsaid conductive segments and responsive to rotation of said segments therepast for producing a pulsed output corresponding to the actual speed of the shaft means, means determining an adjustable speed threshold and means responsive to said pulsed output and threshold for dicontinuing energization of said machine when the rotational speed of said shaft means falls below the expected minimum speed of said machine, represented by the threshold.

Claims

1. Control switch apparatus for a multifunction machine, comprising in combination: means defining a housing mountable on the machine to be controlled; rotatably driveable shaft means rotatably supported on said housing; disk means including a plurality of disk pairs on said shaft means, said disk pairs each including similar relatively circumferentially adjustable first and second slim waferlike disks of insulative material, each said disk having a coaxial flat semicircular layer of electrically conducting material on one radial face thereof and adjacent and within the periphery thereof, the total circumferential extent of such layers corresponding to their electrically effective extent and being variable by relative rotation of said disks; proximity pickup means axially and noncontactingly adjacent the rotational path of said layers of a disk pair for sensing the total circumferential extent of said disk pair occupied by both overlapping and non-overlapping portions of said layers opposed to said pickup means; spacer means on said shaft means and disposed between said disk pairs for determining the axial location of said disk pairs on said shaft means and frictionally preventing unintended circumferential displacement of said disks with respect to said shaft means.

2. The apparatus of claim 1 in which said pickup means comprises a plurality of proximity pickups supported on said housing in aligned relation with said shaft means, each of said pickups having a slotted sensing portion actuable by electrically conductive material and through which the peripheral portion of the adjacent disk pair is freely but closely rotatable, said first and second disks having opposed radial friction faces in face-to-face contact out to the disk-pair periphery, one said flat semicircular layer being provided on the outer radial face of each said disk of said pair, said layers being of similar circumferential extent and arranged in non-interfering relation with said friction contact faces of said disks.

3. The apparatus of claim 2 in which the disks are of resin impregnateD fiberglass and the conductive layer is a printed circuit-type layer.

5. The apparatus of claim 4 in which said housing includes a shelf extending transversely thereacross in parallel relation with said shaft means and radially spaced therefrom, a plurality of brackets dependently mounted from a longitudinal edge of said shelf and in substantially radial planes of the shaft, pickup means on said brackets, each such pickup means being adapted to straddle one of said disk pairs for sensing orbiting of an electrically conductive portion of said disk pair therepast.

6. The apparatus of claim 5 in which said brackets include a bight wall extending along said shelf edge toward the axis of said shaft means and a leg extending from said shelf edge over the axis of said shaft means, said pickup being removably mounted on said leg and having a sensing slot for receiving the correspondding disk pair periphery looseley therein.

8. The apparatus of claim 7 in which said shaft means comprises at least one shaft member having an axial slot and said spacer means comprises a hollow spacer between and frictionally interengageable with adjacent flanking disk pairs, said spacer including inwardly extending means circumferentially locked but axially movable in said slot of said shaft member for preventing unintended rotation of one said disk upon circumferential adjustment of a disk of the adjacent disk pair.

9. The apparatus of claim 7 in which said resilient bias means comprises an axially compressible spring and at least one said abutment means comprises a nut axially threadedly adjustable on said shaft means for setting the precompression of said spring and means actuable for locking said nut on said shaft means.

11. Control switch apparatus for a multifunction machine, comprising in combination: means defining a housing mountable on the mAchine to be controlled; rotatably driveable shaft means rotatably supported on said housing; disk means including a plurality of disk pairs on said shaft means, said disk pairs each including similar first and second waferlike disks of insulative material, each said disk having a coaxial semicircular layer of electrically conducting material on one radial face thereof and adjacent the periphery thereof; spacer means on said shaft means and disposed between said disk pairs for determining the axial location of said disk pairs on said shaft means and frictionally preventing circumferential displacement of said disks with respect to said shaft means; said spacer means comprising hollow cylindrical spacers snugly received on and slideable axially on said shaft means, and including means preventing circumferential movement of at least selected ones of said spacers on said shaft means and further including axially adjustable compression means for releasably sandwiching together an alternating series of disk pairs and spacers on said shaft means with sufficient force as to prevent unintended relative rotation of said disks and shaft means, and preventing unintended circumferential shifting of adjacent disks, but allowing circumferential adjustment of said disks with respect to each other, with respect to adjacent disk pairs and with respect to said shaft means.

12. Control switch apparatus for a multifunction machine, comprising in combination: means defining a housing mountable on the machine to be controlled; rotatably driveable shaft means rotatably supported on said housing; disk means including a plurality of disk pairs on said shaft means, said disk pairs each including similar first and second waferlike disks of insulative material, each said disk having a coaxial semicircular layer of electrically conducting material on one radial face thereof and adjacent the periphery thereof; spacer means on said shaft means and disposed between said disk pairs for determining the axial location of said disk pairs on said shaft means and frictionally preventing circumferential displacement of said disks with respect to said shaft means; said disk means further including a detection disk having a plurality of uniform and uniformly spaced conductive segments on a radial face thereof and adjacent the periphery thereof, said detection disk being carried by said shaft means for rotation therewith, pickup means fixedly mounted on the housing in overlapped close relation with the orbit of said conductive segments and responsive to rotation of said segments therepast for producing a pulsed output corresponding to the actual speed of the shaft means, means determining an adjustable speed threshold and means responsive to said pulsed output and threshold for dicontinuing energization of said machine when the rotational speed of said shaft means falls below the expected minimum speed of said machine, represented by the threshold.