US2523555A - Electrical device for sorting articles according to dimensions - Google Patents

Description

Sept. 26, 1950 F. R. BOOSEY 2,523,555

ELECTRICAL DEVICE FOR SORTING ARTICLES ACQORDING T0 DIMENSIONS Filed March 8, 1946 3 Sheets-Sheet l Fla. 3.

R505?! Rosier 50055) flfiorneyw Sept. 26, 1950 F. R. BOOSEY 2,523,555

ELECTRICAL DEVICE FOR SORTING ARTICLES ACCORDING TO DIMENSIONS Filed March 8, 1946 3 Sheets-Sheet 2 R I O (1 (j a 2% E as a a R fnyenfor Ram/ck Aaamr 50055) We, M s 4? Sept. 26, 1950 F R BOOSEY 2,

ELECTRICAL DEVICE FOR SORTING ARTICLES ACCORDING TO DIMENSIONS Filed March 8, 1946 3 Sheets-Sheet 3 fiwemfar R500?! Roam? 50065) Patented Sept. 26, 1950 ELECTRICAL DEVICE FOR SORTING AR- TICLES ACCORDING TO DIMENSIONS Frederick Robert Boosey, Letchworth, England, assignor to The Sigma Instrument Company Limited, Letchworth, England, a British com- Application March 8, 1946, Serial No. 653,194 In Great Britain December 1, 1944 Section 1, Public Law 690, August 8, 1946 Patent expires December 1, 1964 4 Claims.

1 This invention relates to machines for inspecting work-pieces and for determining whether the dimensions of such work-pieces are nominally correct or are above the maximum limit of error of tolerance or below the minimum limit of error tolerance.

In the production of work-pieces to some standard pattern it is found in practice necessary to inspect the work-pieces for particular dimensions to determine whether they are correct to tolerable limits of error. It is an object of the invention to devise a machine which will permit this inspection and which will permit also the sorting or grading of the work-pieces according to the accuracy of the dimensions thereof, thus according to whether they are nominally correct, oversize or undersize.

In order that the invention may be clearly understood and readily carried into effect, the same will now be more fully described with reference to the accompanying drawing in which:

Figure 1 is a diagrammatic representation showing the electrical and also indicating the mechanical arrangements of the machine the part of the figure above the line XX being in plan whilst the part below the line X-X is in elevation.

Figures 2, 3 and 4 illustrate various working positions of a switch device shown in Figure 1,

Figure 5 is a side elevation, drawn as a section along the line VV of Fig. 6, of a machine embodying the invention, and,

Figure 6 is an end view corresponding to Figure 5, being a section taken along the line VI-VI of Figure 5.

Referring first to the diagrammatic representation of Figure 1, it will be seen that there is a measuring device I having a gauging anvil 2 contacted by the shorter arm of a bell-crank lever pivoted at 3. A tension spring 4 serves to hold the bell-crank lever in a position where the shorter arm engages the anvil 2 and causes the same to move with a gauging pressure towards a work-piece W. The free end of the longer arm 5 of the bell-crank lever is adapted to cooperate with either of two electrical contacts 6 and i. There is a second anvil 8 adapted to act as the reference anvil with respect to the primary anvil 2. The measuring device, comprising the bellcrank lever and adjustable contacts 6 and I, per se does not form the subject of the present invention. It will suifice here to indicate that the 'measuring device is arranged and operates in the following manner; when a work-piece W lies between the reference anvil 8 and the prima y gauging anvil 2, adjustments of the anvils are so made that if the dimension of the work-piece W which is being gauged, is nominally correct, the gauging anvil 2 moves in such manner that the bell-crank lever controlled thereby has its arm 5 held approximately midway between the contacts 6 and 7. If the work-piece should be oversize, i. e. above the maximum limit of tolerance of error, the bell-crank lever swings about its pivot 3 to cause the free end of the arm 5'to engage the contact 1. If the work-piece W is undersize, then the arm 5 engages the contact 6. The contacts 6 and 1 are themselves adjustable towards and away from one another, so that the limits of tolerance concerned with the dimension that is being measured or inspected, can be set upon these contacts. It will be observed that the invention is shown applied to the case where the overall length of the work-piece W is gauged for nominal correctness.

The work-piece W is supported in a conveniently formed gap in the periphery of a disc like rotatable work holder 9. As the work holder 9 rotates, it picks up work-pieces carried in a laterally disposed chute l0 and brings them one at a time between the gauging anvils 2 and 8. Depending upon the size and nature of the work pieces W the chute [0 will be designed in various ways and similarly the rotatable work holder 9 will bear varying numbers of peripheral gapsor gashes for reception of the work-pieces. For the sake of example herein, it is presumed that in one complete revolution of the work holder 9, three work-pieces W will be removed successivelyfrom the chute l9. Thus in one revolution of the work holder 9, the gauging anvils 2 and 8 will gauge three work-pieces.

Adjacent the work holder 9 and on the opposite side thereof from that associated with the feed chute In, there is a discharge chute passag ll. As seen in the elevation in the lower part of Fig. l the discharge chute II has its lateral walls continued by shutters l2 and 13. The shutter I2 is pivoted as at I4 and has a contro1 link I5 connected pivotally to it, such link being also connected to one end of a further link [6 which is pivotally supported as at I! upon the core of an electro-magnetic device. A winding [9 upon the core [8 when energized is capable of attracting the end [6A of the lever [6 towards the core extremity [8A. There is carried about the pivot M an auxiliary directing shutter 20 arranged to perform angular movement with the shutter I2. I

It will be appreciated that if the winding l9 is energised, the arm IE will swing about its pivot I9 and will cause the link Hi to have a translational movement to the right as seen in Fig. 1. Thus the shutters I2 and 20 will swing in clockwise direction about their pivotal support l4 and th shutter |2 will lie across the chute passage I. Thus any work-pieces which enter the chute II will be deflected b the shutter l2 and further deflected laterall by the shutter 20. Spring means may be provided or the shutter 20 may b Weighted, so that the normal position of the shutters l2 and 26 is that illustrated.

The shutter I3 is associated with an electromagnetic device having a winding 2 I, which electro-magnetic device is of precisely the same type as that described in connection with the control of the shutter l2. The shutter i3 has also the auxiliary deflecting shutter 22 associated with it in th same way that the shutter 20 was associated wtih the principal shutter |2. The electro-magnetic device having the winding 2| is similarly equipped with an arm 23 which responds to energization of the winding 2| and serves to bring the shutter 13 away from a normal position shown, to the position where it lies across the chute passage I.

If either the winding 19 or the winding 2| is energised, then either the shutter l2 or shutter 13 will serve to deflect any component entering the chute passage either to the left or to the right as seen in Fig. 1. If neither of the winding is energised, then a work-piece passes through the chute passage H and drops vertically downwards without lateral deflection.

In a way which will become apparent from the description which follows hereinafter with reference to Figs. 3 and 4, the rotatable work holder 9 moves synchronously with a rotating disc 24. The latter is formed with three sets of cam surfaces for co-operation with a follower 25. Three sets of cam surfaces are provided for the reason that the work holder 9 is gapped at three equiangularly displaced peripheral points for reception of three work-pieces W in a complete revolution. Each set of the cam surfaces comprises a lowest surface 26 an intermediat surface '21 and an uppermost surface constituted by the periphery of the disc 24 itself. For convenience in the diagrammatic illustration of Fig. 1, the cam follower 25 is shown as a finger whereas in the illustration of Figs. '2 to 4 the cam follower appears as a roller. In practice the provision of a roller is preferred. The follower 25 is mounted upon -a spring blade 28 carrying an electric contact 29. A further spring blade 30 carries a contact 3| for co-operation with the contact 29. The spring blade 30 carries additionally a contact 32 adapted to co-operate with a contact 33 carried upon a third spring blade 34. The relative arrangement of the three spring blades 2-8, 34 and 30 and the contacts carried thereby in relation to the cam disc 24, is such that the two pairs of electrical contacts may have three operative positions. The first operative position is shown in Fig. 2 and it will be seen that the follower 25 is on the lowest surface 26 of a set of cam surfaces upon the disc 24, and the contacts 29 and 3| are engaged whilst the contacts 32 and 33 are open. When the cam disc 24 rotates in the direction indicated by the arrow thereon, the follower 25 rises on the intermediate cam surface 2'! and causes the spring blade 28 to flex upwardly and the spring blade 30 follows such movement causing the contacts 33 and 32 to engage. Thus in this position both the contact pairs are closed.

Finally, as the cam follower 26 rises on to the uppermost cam surface level, the blade 28 flexes upwardl to an extent which cannot be followed by the blade 30 whose flexing is resisted by the blade 34, and as a result the contact pair 29 and 3| opens. The contact pair 33, 32 does however remain closed.

The spring blade 34 is connected to a terminal 35 which may be considered as one side of the source of electric supply for the machine. The other side of the source of electric supply is connected to terminals 35 and 31 which are each joined to one side of windings l9 and 2|. The other sides of these windings are joined by leads 38 and 39 to the contacts and 6 respectively of the measuring device I. The lead 39 is joined to one of a pair of switch elements 40, the other of which is connected by a lead 4| to the spring blade 30. The. latter is joined to a similar switch 42 which isalso connected to the lead 38. The switches '49 and 42 are similarly arranged for operation, the switch 40 being closed when the arm l6 encounters it, following energisation of the wind-ing l9, and the switch 42 being closed whenthe arm 23 encounters it by virtue of energisation of the winding 2|. The third spring blade 28 has a lead 43 connecting it with the arm 5 of the bell-crank lever within the measuring device I.

A complete cycle of operation of the machine will now be described to indicate more particularly the operation of theelectrical system. It is assumed that a source of electric current is applied as between the terminal 35 and the terminals 3B and 31. It will further be assumed that the work holder 9 is turning so as to bring workpieces from the chute [0 into the gauging position illustrated in Fig. 1. The angular motion of the work holder 9 will not be of uniform velocity for the reason that the gauging operation performed upon the work-piece W will take a few instants of time and it is necessary that the work-piece should be stationary during the measurement. The motion of the cam disc 24will be uniform and will be synchronised with the movement of the work holder 9 to the extent that both will make a complete revolution in the same time. In the commencement of the cycle to be described, a work-piece W is between the gauging anvils 2 and 8 and is momentarily stationary in this position. The follower 25 is then upon the lowest cam surface 26 and therefore the contact pair 29, 3| is closed whilst the pair 32, 33 is open. The primary gauging anvil 2 performs its gauging movement and causes the bell-crank lever having the arm 5 to take up a corresponding position. If the work piece W is nominally correct, the arm 5 engages neither of the contacts 5 and 1. Supposing that the work-piece W is oversize, i. e. of size greater than permitted by the maximum upper limit of error tolerance, then the arm 5 will swing over to engage the contact 1. It should be particularly noted that no electric circuit is completed by engagement of the arm 5 with the contact and therefore no sparking will interfere with the accurate gauging operation. The gauging operation is of course instantaneous and after it has taken place the disc 24 has turned to a position where the follower 25 rides up to the intermediate cam surface 27 (Fig. 3). In this position of the switches controlled by the cam disc 24, which switches may be identified collectively as the master switch, both the contact pairs 29, 3| and 32, 33 are closed. The closing of the pair 32, 33 closes :a circuit from the supply terminal 35 through the closed contacts 3|, 29 and via the lead 43 to the arm 5. The arm 5 is however, already in engagement with the 1 contact and therefore the circuit is continued through the lead 38 and through the winding 2| to the terminal 35 connected with the other side of the electric supply. The winding 2| is enercauses the follower to rise up on the uppermost cam surface corresponding to the peripheryof the disc. The contact pair 32, 33 remains closed whilst the contact pair 29, 3| is opened. In. this position of the master switch, the circuit previously described as being closed and includin the measuring device I, is broken since the lead 43 from the measuring device no longer has electrical connection with the terminal 35. The winding 2| does however, continue to be energised for the reason that the switch 42 has been closed and p the contact pair 32, 33 remain closed. A closed circuit therefore exists between the terminal .via the contacts 32 and 33, the switch 42, the

winding 2| and the terminal 36 connected with the other side of the supply. The work-piece holder 9 now continues its rotary movement and carries the work piece W away from the gauging position and discharges it into the chute II. It has in this example, been gauged as oversize, and the shutter l3 will deflect it laterally to the right as seen in Fig. 1.

If the gauging operation had caused the arm 5 to cooperate with the contact 6, corresponding to undersize of the work-piece W, then a precisely similar action would have followed except that the winding |9 would have been energised and the shutter l2 would have been brought to lie across the discharge chute passage I. In this case the undersize component would have been laterally deflected to the left. If the work-piece W had through without lateral deflection by either of the shutters.

It is important to note that as soon as the gauging operation is complete. the measuring dc vice is effectively cut out of the electrical cir cuit, by opening of the contacts 29, 3|. It will be appreciated that if these contacts did not open when the work-piece moved from the measuring position, the gauging anvil 2 would be able to move freely towards the reference gauging anvil 8 and therefore the measuring device would tend to set itself in the position where the arm 5 engages the contact 6, corresponding to an under-= size work piece. If the circuit of the measuring device had not been broken the energisation of the winding l9 would follow whilst the winding 2| was still being energised. Obviously, this would result in a highly undesirable operation of the machine.

the deflecting shutter |3 has been in its deflect ing position. When the follower 25 falls to the lowest cam surface 26 the contacts 32 and 33 are opened and hence the master switch is disconnected from the supply terminal 35. Under these circumstances the winding 2| has its circuit broken and it cannot hold its associated deflecting shutter |3 in the deflecting position. The shutter |3 thus returns to the position actually illustrated in Fig. l. The next work-piece is now in position for gauging-and the cycle recommences.

It will be clearthat if so desired signal lamps could be introduced into the electric circuit described above and could serve to indicate whether the winding 2| or the Winding I9 had operated, and would therefore serve to indicate whether a component or work-piece had beengauged'as oversize or undersize.

In Figs. 5 and 6 of the drawings, a machine is shown which represents a practical realisation of the diagram of Fig. 1. The machine has a base 44 from which pillars 45 rise to support a bed 46. A casing 41 encloses the space between the base 44 and the bed 45. The bed carries a slide 48 upon which there is supported a stock 49 in such manner that the stock may be locked in any desired position of adjustment along the slide 48. A measuring or gauging device 50 is adjustably carried in the stock, such gauging device possessing a gauging anvil 5| which is free to perform gauging movements. The body of the device 50 houses the bell-crank lever possessing the arm 5 shown in Fig. l. Mounted upon the bed 46, there is a block 52 which is bored to receive a member 53 adapted to actas the reference anvil. The member 53 is generally of cy=- member 53 has a collar 55 secured to it and a I coil spring 55 abuts one side of such collar and also the block 52, so that the anvil member 53 normally tends to move away from its gauging position.

Below the anvil member 53, the block 52 supports the work holder 56 which is formed as a circular plate and has equi-angularly spaced peripheral gashes, for example, three in number, for the reception of workpieces. The number and shape of the peripheral gashes will vary according to conditions such as for example the size of the work pieces and their shape The work holder 56 is seated upon a shaft 5'! and is in driving connection therewith through a collar 58 keyed to the shaft and possessing a peg 59 which enters the work holder body 56. The extremity of the shaft 58 has a reduced diameter portion 60 which is externally screwthreaded for co-operation with a knurled internally screw-threaded control head 6 I. When the control head El is tightened, the shaft 51 is drawn longitudinally to the right as seen in Fig. 5. The shaft 51 is supported upon ball- bearings 58 and 59 mounted in the block 52, and carries freely upon it a disc 60 provided with face cams 6| In the position of the disc 50 shown in Fig. 5,

only one of the face cams H is visible, but it will be understood that if the work holder 55 has three gashes for reception of work, then there are three face cams 5| upon the disc 60*",

such cams being angularly spaced by dc grees. There are likewise three apertures formed in the disc 60, one of which only is seen in Fig. 5. Each of these apertures has a plunger 62 entered in it, such plunger having a conical face 63 for engagement with the head 54 of the anvil member 53'. Behind the plunger 62, there is an integrally formed collar 64 and rod 65, which latter fits into a corresponding aperture formed in Z A spring 6'! bears afurther disc member 66. against the face of the disc member 66 and one side of the collar 64 and thereby tends to press the conical head 63 always in a direction where it projects to a maximum extent limited by the collar 64 through the disc 60 The disc 66 rides freely upon the shaft 51 and the head 61 of the shaft fits into a depression in the centre of the disc. A sprocket wheel 68 is secured as by machine screws 69 to the disc 66. There is effectively secured upon. the shaft between the discs 60 and 65 a collar 10 which has a radially projecting peg H. A coil spring 12 is located upon the collar 10 and has one end anchored to the peg H. The other end of, the coil spring passes around a peg 13 secured to the disc 66.

The face cams 6| upon the disc 60* are intended to cooperate with the mushroom head 74' formed upon a plunger rod '15 slidable in a bore of the block 52. A collar 16 upon the plunger rod bears against one end of a spring 11 the other end. of which abuts the block 52. The end of the plunger rod 15 projects beyond the block and is adapted to encounter stops. [3 I carried upon the adjacent side face of the circular work holder 56. There are three stops 18 disposed symmetrically about the face of the work holder.

An electric motor 19 is mounted upon the, bed

- (not shown) is arranged to control the motor 19 so that when desired the output shaft 80 revolves. The revolution of the output shaft 80 causes rotary motion to be imparted to the sprocket BI, and thus to the sprocket wheel 68. The latter positively drives the disc 66 which similarly positively drives the disc In; the illustrated position of the mechanism shown in Fig. 5, the head 14 of the plunger rod 15. is riding uponone of the face cams BI and as a result the end of the plunger is contacting a. stop 18 upon the work holder 56. The motor 19 serves to drive the sprocket wheel 68 in a clockwise direction as seen in Fig. 6. The work holder 56 is temporarily immobilised by co-action of the stop 18 with the plunger rod 75, and therefore the collar 10 is similarly immobilised. Thus the continued rotation of the sprocket wheel 68 will cause the spring 72 to be wound up, since one end of the spring will be wound by the peg 13 whereas the other end of this same spring will be held fixedly by the peg H. It will benoted that at the time when the winding up of the spring 12' commences, the plunger 62 has its head 63 in contact with the mushroom headv 54 ofthe anvil member 53'. Under these circumstances, the anvil member 53 will be forced longitudinally against the action of its springinto a position where the anvil member 53 projects to a maximum extent from the block 52, and this position of the anvil member corresponds to the gauging position thereof. A workpiece W shown in dotted lines in Fig. 5, then lies between the reference gauging anvil 53 and the primarily gauging anvil 5|.

As the discs 60 and 66 continue to turn, it will be clear that the plunger 62 will be freed from the mushroom head 54 and the anvil member will be able to move backwardly away from the gauging position under the action of its spring. In like manner, the face cam BI will turn away from the head 14 of the plunger rod 15, to free the latter, whereupon the plunger member may move inwardly to disengage the stop 18.. As soon as the stop 18 is so disengaged, the spring 12 will cause the collar 10 to turn until the-peg H contacts the peg 13. The shaft 51 will. be correspondingly rotated and therefore the work piece holder 56 will also turn. It will be accelerated by the energy stored in the spring 12 until the pegs 1| and 13 contact whereupon the work holder 56 will turn in unison with the discs 66 and 60 Such turning movement will continue until the next face cam BI causes the plunger rod 15 to move towards a stop engaging position. The next stop 18 will then be engaged and the work holder positively immobilised. By this time the next work-piece such as W will be in position for gauging and the next plunger .62 will contact the head 54 of the anvil member 53 to cause the latter to move to its gauging position. As before the spring 12 will be wound up and the operation will follow in the manner previously described.

It will now be appreciated that the work holder 56 rotates intermittently there being a pause as each work-piece W comes to the gauging position. This pause may correspond to the feeding of a further work piece W into the work holder 56. After a work piece has been gauged it falls through a gap 83 in the bed 46 and, enters a vertically disposed chute passage therebelow The principal vertical chute divides into two laterally inclining chutes 84 and 85 each associated with a shutter 86 and 81.. In Fig. 5 it has been supposed that the shutter 81 has been operated. by its electro-magnetic control device 88. The nature of the device 88 will be understood when it is realised that this device corresponds to the electro-magnetic device having the winding such as [9 or 2| shown in Fig. 1. The operating arm 89 engages a pin 90 carried upon a member whose movements correspond to those of the shutter 81. The shutter 86 is similarly arranged, but for simplicity of drawing both 7 the electro-magnetic actuating device as also the control pin for the shutter are omitted. It will be appreciated that the shutter 86 may occupy a position where it lies across the main vertical chute corresponding to the position illustrated for the shutter 8'1. The lower end of the main vertical chute has members 9| and 92 which continue it laterally so as to direct components travelling therethrough towards a suitable opening at the front of the machine. Openings such as 93 and 94 communicate with the lateral inclining chutes 84 and 85. When the machine is operating, components passing through the gap 83 will emerge through either of the three openings in the side walls 41 according to whether the components are nominally correct or oversize or undersize.

In Figure 6 it will be seen that the disc 68- is formed peripherally with the three sets of cam surfaces corresponding to those shown in Figs. 1 to 4. The follower roller 25 is carried by a bracket 95 which is pivotally supported at 96. A spring 91 urges the roller into contact with the periphery of the disc 66. A stationary con tact screw 98 provides a contact corresponding to that previously indicated at 31, whilst a blade 99 has a contact I corresponding to 29. The blade has an additional contact llll corresponding to contact 32 and the bracket 95 carries a contact I02 corresponding to contact 33. It will be obvious that this arrangement of the master switch operates in precisely that same way as did the arrangement described with reference to Figs. 1 to 4.

I claim:

1. A machine for inspecting and sorting workpieces according to the results of inspection, comprising a cyclically movable work holder arranged to bring work-pieces to a gauging position and thence to a discharge position, electrical gauging means including a movable electrical contact, a pair of stationary electrical contacts and a gauging anvil arranged to set said movable contact for co-operation with either or neither of said stationary contacts depending upon whether the anvil encounters a Work-piece that is oversize, undersize or correct, a pair of electro-magnetic deflecting devices connected one to each of said stationary contacts and arranged \to selectively deflect discharged work-pieces ac cording to the results of gauging, a master switch [operating synchronously with said movable work- Zholder, a source of electric supply connected at one side to said electro-magnetic deflecting devices, contact devices controlled by the master .switch and consisting of two pairs of contacts, one contact of the first pair being joined to the other side of said electric supply source, the second contact of said first pair being joined in common to the first contact of the second pair and the second contact of said second pair being connected to the movable contact in the gauging means, a connection from said second contact of the first pair to both said electro-magnetic deflecting devices on the sides thereof joined to the stationary contacts of the gauging means, switches in both said connections and arranged to close when the respective deflecting device is operative, and cam control means associated with said master switch to cause said contact devices cyclically to occupy three operative positions in the first of which both said contact pairs are closed, whilst in the second position the first 16 pair is opened whilst in the third operative position the first pair is closed and the second pair opened. v

2. A machine according to claim 1 in which the Work-holder is rotatable and further comprising a transmission system for imparting rotational movements to said work-holder and for cyclically driving said master switch, a spring means interposed in said transmission system between the work-holder and a positively moving part of the transmission system, a stop for pe riodically holding said Work-holder in a workgauging position against the action of said spring means and a reference anvil brought to a work engaging position when the work-holder is occupying a work gauging position.

3. A machine according to claim 2 and further comprising a positively driven element in the transmission, at least one cam upon said positively driven element, a plunger mounted in a fixed structure for co-operation with said cam, stop means upon the work-holder for engagement with said plunger when the latter is operated by said cam to hold the work-holder in a work gauging position.

4. A machine according to claim 3 and further comprising a second plunger adapted to function as the reference gauging anvil, spring means normally urging said second plunger away from the work engaging position, at least one abutment device carried by said positively driven element in the transmission system for periodically urging said second plunger to the work engaging position.

FREDERICK ROBERT BOOSEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,443,193 Phelps Jan. 23, 1923 1,758,268 Wagner May 13, 1930 1,873,315 Dreyer Aug. 23, 1932 1,894,025 Dennison Jan. 10, 1933 2,382,885 Landay Aug. 17, 1945

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