US2727380A - Automatic door spotting device - Google Patents

Description

Dec. 20, 1955 E. H. sPRx-:cKELMExER AUTOMATIC DOOR SPOTTING DEVICE 2 Sheets-Sheet l Filed Aug. 2. 1951 INVENTOR.

bw/N H. PREC/fa 1E/ER Dec. 20, 195 E. H. sPREcKr-:LMEIER 727,380

AUTOMATIC DOOR SPOTTING DEVICE Filed Aug. 2, 1951 2 Sheets-Sheet 2 IN V EN TOR.

e 2,727,380 ICC Patented Dec. 20, 1955 AUTMATIC DR SPTTING DEVICE Edwin H. Spreckelmeier, Cincinnati, Ghia, assigner to The American Laundry Machinery lornpany, Cincinnati, hio, a corporation of Ohio Application August 2, 1951, Serial No. 2352989 10 Claims. (Cl. 6th-14m) has a fixed outer shell or curb, and in which a door in the rotatable drum must be brought into substantially accurate registry with a door in the shell for work loading and unloading purposes.

in washing machines previously known in the art, inching has sometimes been effected manually, and sometimes automatically. Manual methods are laborious, and are ineflcient when superimposed on an otherwise completely automatic operation. Automatic inching methods, as developed in the prior art, were all based on an attempt to bring a rotating drum to a full stop in final registry position. In a commercial laundry machine of substantial volumetric content, with a load of Wet material, an abrupt halt, responsive to a brake-controlling cam or otherwise, cannot be very precisely located by reason of variations in drum speed and drum load, which latter factors determine the tendency of the drum to overrun unless the brake is extremely efficient, and controlled with minute accuracy. In case of an instantaneous stop (which is practically impossible to achieve) or even a sudden stop, there is a considerable strain on all working parts by reason of the inertia shock in stopping a loaded drum. One previous system involved bringing a cylinder to a complete stop at some approximate position past the point of registry, and then running the cylinder backwards against the resistance of an applied brake until registry is reached, whereupon the power is cut off. It is not'considered good practice to run with the brake on, and satisfactory accuracy is difficult to attain in this manner.

One object of the present invention is to provide means for securing accurate registry of relatively movable parts while minimizing inertia shock.

Another object of the invention is to provide a novel and improved method of inching a rotatable drum to a point of registry, with a predetermined time delay between inching steps.

A further object of the invention is to provide means for automatically stopping the movable element substantially short of accurate registry, and then inching said movable element automatically towards accurate registry in a succession of relatively short steps, thereby minimizing the momentum developed during each step.

A further object of the invention is to provide means as dened in the last preceding paragraph and wherein a controlled time delay of short but definite duration is automatically interposed between each such step.

A further object of the invention is to provide means for inching a periodically reversible drum to registry, in combination with means for assuring that the inching process always takes place during rotation of the drum in one specific direction.

A further object of the invention is to provide means yin combination with a multi-compartment drum for automatically inching each compartment door in succession to registry with the door of the shell.

Other objects and advantages will be apparent from a study of the following specification, in conjunction with the accompanying drawings, in which:

Fig. l is a schematic showing, partially diagrammatic, of a rotatable-drum washer and accompanying mechanical and electrical elements and circuits for an effective automatic inching control.

Figs. 2, 3, 4, 5 and 6 are simplified drawings, reduced in size, showing different relative positions of a rotatable drum and its fixed housing.

Fig. 7 is a developed view, in flat form, of the complete peripheral surface of a cylinder cam.

Fig. 8 is a schematic View, similar to Fig. l, but showing another embodiment of the invention suitable for the inching control of a two-compartment two-door drum.

Figs. 9, l0, ll and 12 are simplified drawings, reduced in size, showing diiferent relative positions of a two-compartment drum and its fixed housing.

Fig. 13 is a developed view, in flat form, of the complete peripheral surface of a cylinder cam such as is shown in Fig. 8.

Speaking rst generally, the drawings show two embodiments of the invention. In the iirst embodiment, as illustrated by Figs. l to 7 inclusive, there is shown a rotatable foraminous cylinder or drum 1 with a single door 2 within a stationary outer shell or tub 3, which tub has a door d. in this instance the problem, of course, is to stop the drum at the close of the operating cycle so that the doors 2 and 4 are in satisfactory alignment for work insertion or removal.

Still speaking generally, Figs. 8 to 2.3 inclusive show a rotatable foraminous drum lili, having a partition 3mi) therein which divides the drum into two work holding chambers ltia and ltllb having respective doors 102C: and 10211, the drum being rotatable in a shell or tub 163 having a door lil-l. The controls shown in Figs. 8 to 13 inclusive are adapted to produce automatic inching leading to registry of door 164 with either one of the doors time: or w25.

Identification of control elements Referring now somewhat more speciiically to Figs. l to 8 inclusive there are a number of operatable elements effective upon various electrical circuits which are identifiable by capital letters of the alphabet, and which are here listed in alphabetical sequence for possible reference as the description proceeds.

A is a two-armature switch, one of the armatures, namely A-l having two alternate positions and the other armature A-2 having a single closed position.

B is a manual switch for breaking a holding circuit as a preliminary to stopping the driving motor M.

C is a push button switch having a pair of double pole armatures closed simultaneously, effective in starting and only momentarily operated.

D is a single contact switch, biased to open position, but closed during drum operation by a cam on the outer shell door. lt remains closed through the working cycle.

F is a single contact switch operated by a cam 38 on a timed rotatable cam shaft, this switch being closed for forward rotation of the work-holding drum. (See R.)

N is a brake-release solenoid effective, when energized, to release the brake, which brake is normally springbiased to brake-applied position.

P is a single contact switch operating simultaneously with a three-phase switch in the motor starting circuit.

R is a single contact switch operated by a cam 39 on a timed rotatable cam shaft, this switch being closed for reverse rotation of the work-holding drum. (See F.)

T is a slow speed timer motor for rotating the cam shaft to operate switches F and R in sequence.

W is a single contact switch in the time delay circuit.

X is a single contact switch biased to closed position, but movable to open position by a cam on a cam cylinder 23 at the close of the operating cycle. The cam cylinder 23 rotates in synchronism with the driven shaft.

Y and Z are double contact switches, movable from either one of their contacts to the other by respective cams 33 and 32 on the cam drum 23. They are effective in setting up operating circuits during the inciting steps.

CR is a master relay coil having five operating linked switch armatures identifiable as:

CR-i effective in a first holding circuit.

CR-2 effective in a circuit to timer motor T.

CR-3 effective on solenoid N to release the brake.

CR-I-i effective in inching operations.

CR-S effective in inching operations.

DP is a dash pot for imposing a time delay on the opening of switch W.

FC is a contactor coil effective, when energized, to close a three-phase switch for initiating forward rotation of the drum. It also operates switch P which becomes effective under certain circuit conditions, as will appear.

RC is a contactor coil effective, when energized, to produce closing of a three-phase switch for initiating reverse rotation of the drum.

TD is a solenoid effective, when energized, to close switch W against the restraint of the time delay dash pot DP.

In the description of the second embodiment (Figs. 8 to 13 inclusive) reference numerals will be increased by adding 143/51, and in most instances an element identified, for example, by reference numeral 123 in the second embodiment will correspond in function to the element identified by reference numeral 23 in the first embodiment. Likewise the elements identified in the first embodiment by a capital letter, such as dash pot DP, will be identified in the second embodiment by a capital letter with a prime designation, such as DP.

Starting and completing the washing operation In the following description it may be borne in mind that the purpose of the novel means herein disclosed is to complete an operation, bring the rotatable drum to a complete stop at a substantial arcuate distance short of registry, interpose a momentary time delay, and then approach registry by a series of inching steps, with full stops and momentary time delays therebetween, until registry is achieved.

Referring now to Figs. l to 7 inclusive, and for the time being more specifically to Fig. l, the rotatable drum 1 and the shell 3 have previously been identified, as have their respective doors 2 and 4. Assuming that the drum has been loaded and the doors 2 and 4 have been closed, operation is started by placing switch A in the position shown, closing switch B and briefiy depressing push button switch C. The master relay coil CR is energized by a current proceeding as follows: from L-, conductor 5, door switch D (now closed by cam on closed door 4), conductor 6, armature A-l of switch A, conductors 7 and 8, armature of switch B, conductors 9a and 9, armature C-1 of switch C, conductors 10 and 10-a, coil CR, and conductors 11 and 11-c to L-2. Energization of coil CR closes the switches controlled by armatures CR-l, CR-Z and CR-3, and opens the switches controlled by armatures CR- and CR-S. This circuit is effective while C is operated.

A primary holding circuit independent of push button C is now established through switch arm CR-l as follows: from L-1 through conductor 5, switch D, conductor 6, armature A-1, conductors 7 and 8, armature of switch B, conductors 9-a and 9-b, armature C12-1, conductor 12 to CR, and conductors 11 and 11a` to L-2.

The timer motor T is energized through armature CR-2 as follows: from L-1, conductor 5, switch D, conductor 6, armature A-1, conductors 7 and 8, armature of switch B, conductors 9-a and 9-b, armature CR-l, conductors 12, 10a and 13, armature CR-2, conductors 14 and 15 to timer motor T, and conductors 11a, 11b, 11 and 11e to L-2. Switches F and R are on a spur 14a from this circuit, so that they may energize further circuits whenever either one is closed by a respective cam 38 or 39 on the cam shaft rotated by timer motor T.

When both switches F and R are open, the drive motor M does not start. However, when cam 38 rotates counterclockwise to close switch F, the three-phase switch for forward movement of motor M is closed responsive to energization of coil FC, as follows: from L-l through conductor 5, switch D, conductor 6, armature A-1, conductors 7 and 8, switch B, conductors 9-a and 9, switch armature CR-1, conductors 12, 10a and 13, armature CR-Z, conductors 14 and 14n, switch F, conductor 16, contactor switch coil FC, conductors 17 and .i1-c to L-2. The three-phase circuits through conductors 9i), 91 and 92 now initiate forward rotation of motor M and drum 1, which may be assumed to be counterclockwise in the figures as indicated for example in Fig. 5. When the gap between the high sectors of cams 38 and 39 arrives the switches the coil FC is deenergized by opening of switch F, and the drive motor M comes to a stop in its forward rotation. When cam 39 closes its switch R, and the last enumerated circuit is reestablished except that from conductor 14a it now proceeds through conductor 14h, switch R, conductor 18, contactor coil RC, conductors 18h and 11C to I.-2. The three-phase switch controlled by RC closes, reversing the lines to motor M, which thereupon turns the drum in reverse direction until switch R drops off the high segment of cam 39.

For both forward and reverse rotation it was necessary to energize the brake release solenoid N, and this was accomplished, upon energization of the master relay CR, through armature CR-3 as follows: from L-1 through conductor 5, switch D, conductor 6, switch armature A-l, conductors 7, 7a, and 7b, armature CR-3, conductors 19 and 19a to brake release solenoid N, and thence through conductors 11d, 11b, 11 and 11C to L-2.

Termination of washing operation In order to place the circuits in condition for termination of the washing operation the switch B must be opened. It is here described as a manual type but obviously it could be opened by any suitable timing means. Switch B was in the primary holding circuit previously described, but in the meantime a secondary holding circuit has been established through switch X on cam drum 23 as follows: from L-1 through conductor 5, switch D, conductor 6, armature A-l, conductors 7, 'la and 20 to switch X, conductors 21 and 9-b, armature CR-l, conductor 12, coil CR, and conductors 11 and 11-c to L-2. This, of course, is a secondary circuit independent of switch B in the primary holding circuit, and this secondary circuit is broken at switch X by a cam 22 on cam drum 23 which is rotated in direct relationship (both forward and backward) to the washing drum 1.

Assume that the cam cylinder 23 and drum 1 are both rotating counterclockwise, the position of the cylinder in Fig. 5 indicates that cam 22 is ready to open switch X. Upon a further increment of counterclockwise rotation switch X opens responsive to cam 22 and the following results take place immediately: the primary holding circuit through switch B having already been opened manually, the opening of switch X breaks the secondary holding circuit, master relay coil CR is deenergized, armatures CR-l, CR-2 and CR-3 open and CR-4 and CR-S close; the opening of CR-l and CR-Z has broken the circuit to timer motor T and to switch F (which was closed for counterclockwise or forward motion at the moment) and accordingly the drive motor M stops because its contactor coil FC is deenergized by breaking the circuit through F; the opening of CR-S hasl broken the circuit to the brake release solenoid N, and the brake is applied.

The heavy drum now coasts to a stop with the doors 2 and 4 approximately in the relative position shown in Fig. 2.

In the at developed view of the periphery of cam cylinder 23, as shown in Fig. 7, thenumbelred broken lines indicate the respective positions of switches X, Y and Z for the positions of the drum as shown in the correspondingly numbered Figs. 2, 3, 4 and 6. The arrow indicates forward or counterclockwise movement. it may be apparent that the switces could be moved 'while the cam drum is stationary.

Resumpton of drum rotation followed by inching When the switch X opened, the switch armature CR-S closed as previously described, thereby completing7 a circuit to time delay solenoid TD, as follows: from L-l through conductor 5, switch D, conductor 6, armature A-ll, conductors 7, 7a, 20 and 24 to armature Cit-5, conductor 25, switch Z in its low position (not yet on cam 3T.) conductors 26a and 26C to switch Y (not yet on cam 313) conductor 27 to coil TD, and thence by conductors 28, lli and llc to L-Z. There is a second circuit from the lower contact of switch Z through conductors 26a and 26, the armature of switch P, and conductor 27 to coil TD.

Coil TD, when energized effects closing of switch armature W, but closing movement must be etected against the resistance of a dash pot DP or other time delay mechanism. This may be set to produce a delay of about one second in switch closing movement, but no delay in opening movement, the drum 1 having come to a stop during this time as previously described. When switch W closes a circuit C is established as follows: from L-1 through conductor 5, switch D, conductor 6, switch A-ll, conductors 7, 7a, 2h, and 24, armature CR-S, conductor 25, switch Z in low position, conductors 26a, 26 and .'50 to switch W, conductor 31 to coil FC and thence by conductors 17 and ille to L2. In shunt with this, current also flows through conductor 31a to armature CIR-4, and conductor 19a to brake release solenoid N, and thence through conductors Bild, lib, il and llc to L2. Another circuit is closed through the lower contacts of switches Y and Z and through conductor 27 to switch` P, conductors 26h and 30 to switch W, conductor 31 to coil FC, and also conductor 31a to armature (3R-4 and conductors 19 and 19a to brake release solenoid N.

The brake being released, and coil FC being energized, motor M turns drum il counterclockwise until cam cylinder 23 moves cam 32 under switch Z, which causes Z to break its lower contact and move to its upper contact. Opening of this contact breaks all circuits to coil TD which causes immediate opening of switch W (there is no time delay in the opening direction) cutting ofi the drive motor M, and deenergizing brake solenoid N so that the brake is applied. The drum 1 comes to a stop approximately as shown in Fig. 3 which, as will be seen, is a position not far from registry. The cam cylinder switches will be in approximately the position 3 of Fig. 7, cams 32 and 33 holding switches Z and Y in their upper position.

A circuit is now established from L-'l through conductor 5, switch D, conductor 6, switch A41, conductors 7, 7a, 2t) and 24, armature CR-S, conductor 2.5, switch Z in upper position, conductor 60, switch Y in upper position, conductors 26o, 26, and 2615, switch P, conductor 27, coil TD, and conductors 2li, 11, and 11C to L2. After a one second delay, from the time that switches Y and Z were raised switch W closes completing a circuit as follows: from L-l through conductor Si, switch D, conductor 6, switch A-l, conductors 7, 7a, 2t) and 24 t0 armature CR-, conductor 2S, switch Z in upper position, conductor 60, switch Y in upper position, conductors 26e, ,26 and 30, switch W, conductor 3l, coil FC, and conduce gli) tors 17 and 11C to L2. A simultaneous shunt circuit is established through conductor 31a, armature CR-4, conductor 19a to brake release solenoid N, and back through conductors 11d, 11b, 11 and 11C. lt will be observed that the circuit passing through switch P energized coil TD which closed switch W and energized coil FC so that energization of FC is dependent on switch P being closed. This is most significant from the standpoint of the inching operation.

Energization of coil FC initiates movement of its armature core to close its three-phase, three-contact switch. Simultaneously the fourth switch armature P on the same mechanical hook-up is opened breaking the circuit to coil TD and opening the circuit to contactor FC. The core of coil FC has, however, achieved enough momentum to cause :its three-phase switch blades to make a momentary completion of the circuit to motor M while the brake solenoid is momentarily released. The motor therefore inches the drum forward through a short arcuate step.

The return of switch P to its closed position reestablishes the circuit to coil TD, as described in the second preceding paragraph hereinabove, and again after about one second delay switch XV is closed, and again the shortstep inching impulse is imparted to the drum.

While the circuits as shown and just above described could be modiiied somewhat to cause rapid successive jogs without the time delay, such a rapid series would impose an undesirable strain on the drive motor and other elements, and the time delay gives a satisfactory pause between inching impulses.

After several inching steps switch Y drops off cam 33 (Fig. 4 and position 4 of Fig. 7) thereby opening the circuit to TD, at which point the tub door 2 will be in registry with the shell door 4.

Orientation for inciting when drums first stop is in reverse direction The control is devised so that the series of inching steps are eiected during drum travel in counterclockwise forward direction. lt may, of course, happen that the initial drum stop (when switch X drops on cam 22) occurs when the drum is revolving in a clockwise, reverse direction. In such case the circuits herein provided automatically produce an initial reversal of drum travel so that it will revert to a clockwise direction for inching. This is done as follows.

Assume that the drum is traveling in reverse (clockwise) direction, the drum door 4 being about in the position indicted in Fig. l, and cam 22 being about to open switch X. Bear in mind that in Fig. 7 the cam cylinder periphery is now traveling in a direction opposite to the arrow. Switch B has been opened for initiation of the finishing and inching steps, and switch X being opened by cam 22, the holding circuits for CR are broken as previously described, with consequent cutting ott of drive motor M, and brake release solenoid N. The drum comes to a stop in approximately the position shown in Fig. 6, the switches X, Y, and Z being approximately on the line 6 of Fig. 7.

The switches Y and Z are on their lower contacts, because they are not on the cams 33 and 32.. A preliminary forward rotation occurs, as already described for switches Y and Z in lower position. The drum continues to rotate forward (counterclockwise) until the switch Z is raised by cam 32, the elements coasting to the position of Fig. 3 and line 3 in Fig. 7. The switch Y being also raised by cam 33, all elements have attained the positions already described for initiation of inching in the forward (counterclockwise) direction.

Manual inching control Assume that the drum is operating in a washing cycle in the normal manner and that the operator desires to stop it prematurely, or stop it at the cycle end and inch it manually. He shifts switch A, moving A-l to its right hand contacgand closing A-2. Switch B need not be opened. Opening the left contact of A-l breaks the circuit to master relay CR which originally passed through conductors 7 and 8, switch B, conductors 9a and 9b, armature CR-l, and conductor 12 to CR, and the deenergization of this relay cuts off the current to drive motor M as previously described, and also deenergizes the brake solenoid N so that the brake is applied.

With the drum at rest the operator rotates or inches it (either forward or backward depending on its circuit controls as established when it stopped) by use of pushbutton C. While doing so the operator has a visual guide, or door spotting indicator 34. The circuit responsive to button C is as follows: from L-1, through conductor 5, switch D, conductor 6, right hand contact of switch A-1, conductor 35, switch contact C-2, conductor 7d, switch contact A-2, conductors 37 and 9 to switch Contact C-1, conductors 10 and 12 to master relay coil CR, and thence by conductors 11 and 11C to L-2. In shunt therewith the current from conductor 10 (as above) proceeds through conductor 13 to armature CR-2, and thence by conductor 14 to the reversal control switches F and R, so as to energize the drive motor M through one or other of the contactors FC and RC. Simultaneously there is a circuit from conductor 6, right hand contact of switch A-l, conductor 35, switch contacts C-2, conductors 7d, 7c, 7, '7a and 7b to CR-3, and conductors 19 and 19a to the bralle release solenoid N. This circuit continues only while push-button C is held operated.

To summarize the functions of the switches A, B and C, during normal running operation A is in its left position (Fig. 1), B is closed, and C is momentarily operated until the holding circuit is completed, after which C may be released. For automatic inching B is opened. For a stop at any time A is moved to the right. When thus stopped, manual inching can be done by switch C.

All control circuits enumerated hereinabove passed through door switch D. When inching is completed, or when stopped for any reason and the shell door is opened, switch D opens and effectively cuts all power to the powered control and drive elements.

Multiple compartment washer: starting and running In the previously described embodiment the problem involved aligning a single door in the open pocket (single compartment) drum with a single door in the shell. ln the embodiment now to be described the problern involves causing inching alignment of a rst door in a lrst compartment with the shell door, and upon completion of the unloading of the rst compartment, causing inching of the second compartment door to alignment f with the shell door.

In the following description means are provided to assure that forward drum rotation is counterclockwise, and that inching takes place in this direction. In Fig. 8 the drum is stopped, the cam cylinder 123 being so positioned that the cam switches are shown in normal depressed position.

Assuming that drum compartments 10111 and 101b have been loaded in the usual way, the operator sets switch A' as shown (it normally remains in this position), closes switch B' and depresses push-button switch C', thereby energizing master relay coil CR' as follows: from L1 through conductor 105, door switch D', conductor 106, left hand contact of switch A'-1, conductors 107 and 108, switch B', conductors 109 and 110, left set of contacts of switch C', conductor 111 to master relay coil CR', and conductors 112 and 112a to L2.

A holding circuit is now established, by reason of e11- ergization of coil CR', for maintaining CR' energized, as follows: from L1 through conductor 105, switch D', conductor 106, switch A'-1, conductors 107 and 108, switch B', conductors 109, 110e, and 113 to armature CR'1, coil CR', and conductors 112 and 112a to L2. Pushbutton C may now be released.

Closing of armature CR'2 continues the last mentioned circuit by conductor 114, armature CR'2, conductor 115 to switches F' and R' for forward and reverse control (as in the previous embodiment) and to timer motor T' and thence to L2.

The brake release solenoid is energizable through switch A21, conductors 107, 107e and 116, armature CR3, and conductors 117e and 117 to the brake release solenoid N', and thence to L2 as the diagram shows.

The washer now operates in normal manner, switches F and R', when alternately closed by their respective cams, reversing the rotation of the drum as in the previous embodiment, the F' contactor coil FC' being responsive to switch F' for forward rotation, and the coil RC' being responsive to switch R' for reverse rotation. Also, as previously, coil FC' operates not only its three threephase blades, but also a fourth switch P' which opens when the three blades close, and vice versa.

At the termination of a pre-determined washing cycle switch B' is opened either by the operator or by timed control means. This breaks the original holding circuit but there is another circuit through switch X' on cam cylinder 123 (Figs. 8 and 13) as follows: from L1 through conductor 105, switch A'-1, conductors 107, 1070, and 107e to switch X', and by conductors 110!) and 113 to CR'-1 and to CR', and thence by conductors 112 and 112i: to L2. Switch X' is operated by a short cam 1.22 on cam cylinder 123, the cam cylinder being operated directly from the work-containing drum as before.

Inclzz'ng control for first compartment of second embodiment This description will be abbreviated to essentials, since it will be readily understood after studying the inching control described herein for the iirst embodiment.

As before the drum should be rotating forward when inching is initiated. The running circuit is temporarily maintained by a switch V operable by a cam 40 on the timer motor shaft. The reversal control cams for switches F and R' are so set with respect to switch V that switch V and switch R are closed simultaneously, the drum being in reverse direction at such time. Thus, if the switches B' and X' are operated in sequence when the drum is in reverse rotation, a third holding circuit through switch V temporarily prevents deenergization of the master relay CR', such circuit running from conductor 107, 107a and 107 b to switch V, and thence through conductors 118, b, and 113 to CR'-1 and to CR' as previously. The drum will therefore continue until it goes into forward rotation under the influence of switch F'.

When cam 122, now rotating forward, opens switch X' the last holding circuit is deenergized, as is also coil CR'. The circuits to the brake solenoid N', to the timer motor T', and to the drive motor M' are broken through their respective three switch armatures in the CR' group (although armatures CR'4 and CR-5 in the inching circuits now close). Drum 101 has stopped in approximately the position indicated in Fig. 9 with its door 10211 a short distance from registry with tub door 104. The cam drum has moved a corresponding distance, the cam switches being in alignment along the line 9 of Fig. 13. When cam 122 passed switch X' all three switches X', Y' and Z' were momentarily in their low positions, and a circuit was completed from switch A-1, through conductors 107, 107er and 116 to now closed switch CR'-5, and conductors 119 and 11951 to switch Z' in its low position, then to switch Y' in its lower position, and thence through conductor 121 to coil TD' which operates a one-second time delay dash pot DP', and thence to L2. Another circuit to this coil was established from the lower contact of switch Z', line 120, switch P', and line 121e to switch Y and through the lower contact of Y' through conductor 121 to coil TD'. However, switch Z' very rapidlywas moved to its upper contact by cam 132:1 breaking the above two circuits. Immediately thereafter switch Y' was moved to its upper Contact by its cam 133a. This established a circuit from switch A'1, conductors 107, 167e and 116 to CR-5, conductor 119 and 11961 to switch Z', upper contact, conductors 124 and 125 to upper contact of switch Y', conductor 120 to switch P and conductor 121er to coil TD'.

Coil TD', retarded by its dashpot, will close its switch W shortly after the drum has stopped, thus establishing a circuit through conductors 120 and 120a, switch W', conductors 12d and 127, contacter coil FC' to L2, and continuing through conductors 126g, 126b and 126e to armature CRY-4, and through conductors 131) and 117 to brake release solenoid N.

As in the previous embodiment thisy starts a forward jog of the drum, which is immediately interrupted by the opening of switch P in the FC' armature system, breaking the circuit to coil TD. Switch W' opens, breaking the circuits to coil FC' and coil N so that the brake is applied, and the forward jog is small. The switch l" again closes, reestablishing the circuit to coil TD' which, after a brief time delay, closes switch W repeating the inching step. After several of these inching movements, as indicated by the left hand series of parallel dot-dash lines i in Fig. 13, the cams will have moved to the position in Fig. 13 at which point switch Y will drop to its lower contact, breaking the circuits to TD and W', and the drum door 102a is in registry with shell door 104.

The cam rises on the cam drums 23 and 123 can be adjustably fixed peripherally so as to be in proper operational synchronism with the drum operation.

Inc/ting control for second compartment of the second embodiment After unloading the irst compartment, and closing the doors the operator presses a button Rl which establishes a circuit from switch A'-1, conductors 1117, lila, 116, now closed switch armature CR-5, conductors 119 and 11951, switch Z', upper contact, conductors 124 and 125a., switch R1', and conductor 131 to a relay coil CRb and thence by conductor 112e to L2. Contact CRb-l closes, establishing a maintaining circuit for coil CRI) by conductors 134, 125, and 124, upper contact of switch Z', conductors 119e and 119, armature CR-5, conductors 116, 10% and 107", switch A-1, conductor 1116, switch D and conductor 105 to L-l. In addition another circuit runs from line 119 of this circuit to CRb-Z, conductors 1265!, 126e, CFI-l, and conductors 130 and 117 to brake release solenoid N'. Another extension of this circuit goes by conductors 126d, 12611, 12611 and 127 to coil FC'.

The drum now rotates further forward and when switch Z' drops oil cam 132a it thereby breaks the maintaining circuit to relay CRI), which opens, breaking the circuit to FC' and to brake solenoid N. The drum comes to a stop with its door 10211 approximately as shown in Fig. ll, and the control cams as indicated at 11 in Fig. 13. For the second compartment, 101i), stopping was effected by switch Z dropping oi cam 132e as compared to initial stopping by cam 122 opening switch X.

Cams 132i: and 1335 have operated their switches, as previously described, and jogging or inching now proceeds until switch Y' drops oil cam 133b, at line 12 of Fig. i3, the relative positions of drum and shell being as shown in Fig. 12.

This completes the normal unloading cycle for both compartments, but, if desired, the push-button RI can again be operated so as to bring the iirst compartment (191e) back to registry with shell door 104, and in this case the dropping of switch Z off cam 13211 initiates the stopping for compartment 10161, cam 122 and switch X' being ineiiective until the washer is returned to normal running operation.

Manual inching and circuit operations involved thereby are the same as previously described for the rst embodiment.

What claim is:

1. A washing machine comprising a fixed casing, a work holding drum rotatable within said casing, said drum and said casing being provided with respective doors which must be brought to 'a position of registry for work loading and unloading, and a controller for inching said drum door into such registered position comprising an electrical power circuit for rotating said drum, means for yautomatically interrupting said circuit while said drum door is a substantial angular predetermined distance short of registry, means for stopping said drum, means automatically effective at such interruption to establish other electric power circuit means for initiating resumption of rotation of said drum, furtherautomatic means for alternately momentarily permitting electric ow in said last named circuit means, and for terminating said flow Whereby said drum is advanced towards registry in a series of relatively short inching steps, and automatic means for causing a final stoppage of said drum when said registry is achieved.

2. A washing machine comprising a fixed casing, a work holding drum rotatable within said casing, said drum and said casing being provided with respective doors which must be brought to a position of registry for work loading and unloading, and a controller for inching said drum door into such position comprising an electrical power circuit for normal working rotation of said drum, means for automatically interrupting said circuit while said drum door is a substantial predetermined distance short of registry, means for automatically stopping said drum upon interruption of such circuit, means automatically effective at such interruption to close other electric circuits for initiating resumption of rotation of said drum, further means for alternately intermittently terminating flow in said other electric circuits, and for reestablishing such flow, whereby said drum is caused to advance towards registry in a series of relatively short inching steps, means for automatically controlling the duration of time delays between respectively successive steps, and means for automatically causing a nal stoppage of said drum when the aforesaid position of registry is reached.'

3. A washing machine comprising a fixed casing, a work holding drum rotatable within said casing, said drum and said casing being provided with respective doors which must be brought to a position of registry for work loading and unloading, and a controller for inching said drum door into such position comprising rst electric circuit means which, when closed, causes normal working rotation of said drum, means for automatically opening said circuit and for automatically stopping said drum while the drum door is a substantial predetermined distance short of registry, means automatically effective when said first circuit is opened to thereafter establish other electric circuit means for automatically initiating resumption of rotation of said drum, a control switch in said other electric circuit means for automatically permitting or preventing ow of power through said other electric circuit means whereby, upon intermittent opening and closing of said switch, said drum is automatically caused to advance towards registry in a series of relatively short inching steps with stops therebetween, time delay means operatively linked to said switch, and automatically effective thereupon whereby to control the duration of a time delay between successive inching steps, and means for causing a final stoppage of said drum when the aforesaid position of registry is reached.

4. In a washing machine wherein a work-holding drum is rotatable within a fixed casing, and wherein said drum and said casing are provided with respective doors which must be brought to a position of registry for work loading and unloading, a controller for automatically inching said drum door into such position comprising a driving circuit which, when closed causes normal working rotation of said drum, means for automatically opening said driving circuit to cause stoppage of said drum while the drum door is a substantial distance short of registry, and inching control means comprising a power circuit including a motor for automatically supplying inching impulses to said drum, a contactor switch in said power circuit, a contactor coil which, when energized, automatically closes said contactor switch, a contactor coil circuit for automatically energizing said contactor coil, a time delayed switch in said contactor coil circuit, a second coil which, when energized automatically closes said time delayed switch, a time delay instituting circuit for automatically energizing said second coil, an interrupter switch in said time delay instituting circuit, said interrupter switch and said contactor switch being mechanically linked in such way that when either one opens the other closes whereby when said contactor coil is energized by closing of said time delayed switch to move its contactor switch to closed position it causes opening of said interrupter switch, and consequent breaking of said contactor coil circuit, said contactor switch being adapted to complete its movement to momentary closed position despite opening of said interrupter switch, whereby to produce an inching movement of said drum, said inching cycle being repeated when said interrupter switch closes.

5. An inching controller as defined in claim 4, and wherein said time delayed switch is provided with means for controllably retarding its movement to closed position when said time delay instituting circuit is energized.

6. An inching controller as defined in claim 4, and wherein means is provided for automatically causing a final stoppage of said drum when said drum door reaches the aforesaid position of registry.

7. An inching controller as defined in claim 4, and wherein said contactor switch assembly is of sufiicient mass to close by its own momentum upon receiving an initial closing impulse, despite termination of such impulse before the contactor switch reaches closed position.

8. An inching controller as defined in claim 4, and wherein means is provided for causing said drum to rotate in a predetermined direction before said inching circuits become operative.

9. In a washing machine wherein a work-holding drum is rotatable within a xed casing and wherein said drum and said casing are provided with respective doors which must be brought to registry, in combination, means for automatically producing a preliminary stop of said drum when the drum is in a predetermined angular position short of registry, means thereafter operable independently of said rst mentioned mans for automatically effecting stopping of said drum in a series of predetermined angular positions successively approaching registry, and means for automatically controlling the duration of each such stop after reaching respectively successive angular positions.

10. In a washing machine wherein a work-holding drum is rotatable within a fixed casing and wherein said drum and said casing are provided with respective doors which must be brought to registry, in combination, means for automatically producing a preliminary stop of said drum when the drum is in a predetermined angular position short of registry, means thereafter operable independently of said first mentioned means for automatically effecting stopping of said drum in a series of predetermined angular positions successively approaching registry, and means for finally stopping said drum with its door in registry with the casing door.

References Cited inthe file of this patent UNITED STATES PATENTS 1,786,554 Van Valkenburg Dec. 30, 1930 2,334,965 Thacker Nov. 23, 1943 2,537,269 Harding Jan. 9, 1951

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