US2481629A - Interlock mechanism - Google Patents

Description

Sept 13, 1949., (i a, THiEME 2,481,629

INTERLOCK MECHANISM 7 Original Filed July 1., 1944 3 Sheets-$heet 1 IJNVENTOR.

- 2 601685, 7%iefiw. BY 9 Sept. 33, 1949. G. B. THIEME 2,481,629

INTERLOCK MECHANISM Original Filed July 1. 1944 3 Sheets-Sheet 2 j 27 [6 px E a6 14 v. H34\ 1 w "A J. 44

W 9.11 -x w INVENTOR.

Geer a'e B. Tlzieme Sept. 13, 1949s 3 Shee'ts-Sheet 5 Original Filed July 1, 1944 Ill/1111121111), I

m 1 1 m Q m r M v Q My x h o m i m mi W 0 A 0 Q? E Patented Sept. 13, 1949 INTERLOCK MECHANISM George B. Thieme, Jamaica, N. Y., assignor to Bendix Aviation'Corporation, Norwood, Mass., a corporation of Delaware Original application July 1, 1944, Serial No.

Divided and this application March 11, 1946, Serial No. 653,673

4 Claims.

The present invention relates to interlock mechanisms, more particularly mechanisms for compelling a certain sequence of operations to be carried out, as for instance in the opening and closing of valves in a chemical reaction conduit system, especially operations in which a time factor is involved, to insure the carrying out of a process in predetermined manner, although it is not limited to such use.

This application is a division of my application No. 543,187, filed July 1, 1944, and issued March 19, 1946 as Patent 2,396,759.

A novel interlock mechanism is provided which makes it possible to set up a predetermined sequence of locking and interlocking operations requiring the use of a set of keys, thereby eliminating the need for human supervision, inasmuch as the interlock mechanism of the invention compels or enforces insertion and removal of keys from the device in predetermined sequence, and prevents key withdrawal until a certain time interval has elapsed. By varying the key holding and releasing action, and the length of time the key or keys will be held, interlocking mechanisms may be provided in accordance with the invention to afford control of various types of operations.

It is accordingly a primary object of this invention to provide a novel interlock mechanism which will constantly retain one of two keys against removal, and which, upon rotation of one of the keys through a predetermined angle, will lock both keys against removal until a predetermined time interval elapses.

Another object is to provide a signal device to indicate the duration and/or termination of said predetermined time interval.

A further object is to provide novel electrical operating and control means for said signal device, as well as for the system as a whole.

The invention further aims to provide, in an interlock mechanism, novel switch actuating and lock cylinder arresting mechanisms; a novel cam assembly for controlling the operation of adjacent lock cylinders; a novel mount for the interlock assembly; and further novel interlock improvemints and refinements to be hereinafter pointed ou Further objects will become apparent as the specification proceeds in conjunction with the anneXed drawings, and from the appended claims.

In the drawings:

Figure 1 is a vertical sectional view through an interlock mechanism embodyingone form of this invention, taken substantially on the line I-I of Figure 3;

Figure 2 is a vertical sectional view through the apparatus taken along a vertical plane disposed at right angles to the plane of Figure 1;

Figure 3 is a horizontal sectional view taken along the line 3-3 of Figure 2;

Figure 4 is a view showing the wiring diagram for the apparatus of Figures 1 to 3 inclusive.

With continued reference to the drawings, wherein like reference characters have been employed to designate similar parts throughout the several views, I have illustrated the invention as being applied to an installation requiring incorporation of the switch parts in a gas and explosion proof casing l0, equipped with end closure caps H and [2. However, it is to be understood that the invention is not limited to use with a casing of this character. Case ID is provided with mounting lugs l3 for supporting it in any desired man ner.

The interlock mechanism of the invention is installed in the casing in novel manner, permitting maximum accessibility with a minimum of mounting structure.

Supported on a flat upper surface of casing 10 is a housing l4 having a closure I5 secured thereto in sealing relationship by means of cap screws [6 and a gasket [1. Secured to the upper face of closure l5, by means of cap screws H! or the like, are lock assemblies 19 and 2| having keys 22 and 23 respectively cooperating therewith in wellknown manner. A sheet metal thimble 24 is clamped under each lock barrel assembly and is provided with a closure 25, the latter being anchored to the top of closure 15 by a retaining chain 26, and suitable swivel connections. a

The lock barrels shown are of well-known character and include shank portions projecting through openings in closure I5, and terminating in rockable shaft elements 21 and 28 respectively which are operatively engaged with coupling members 29 and 3|. The latter transmit rocking movements of the lock barrel shafts to the inter-: lock mechanism located within casing IS, in the manner now to be set forth.

Couplings 29 and 3! are engaged with rock shafts 32 and 33 respectively projecting into casing l0, and from the foregoing it is apparent that if it were not for the novel interlock mechanism of the invention, shafts 32 and 33 could be rocked at will by inserting keys 22 and 23 in their looks and turning them.

While shafts 32 and 33 may be coupled to the interlock mechanism of the invention in various ways, I preferably employ a novel assembly of parts which functions to efficiently journal the shafts for rocking movement; to secure housing H to housing l; and also to operatively support the entire interlock mechanism in the housing as a unit. To this end shafts 32 and 33 are journalled in flanged bushings 34 and 35, respectively, which as seen in Figure 1, are threaded into tapped openings in the upper wall of housing l3,

and function to secure casing l4 in tight engagement therewith. Collars 36 and 31 secured to the upper ends of the shafts maintain them in proper vertically adjusted position. Tightly threaded on to the lower ends of bushings 34 and'35 are complemental bushings 38 and 39, respectively. The latter have reduced lower ends which project through openings in the upper plate 4| of a framework including a bottom plate 42 and intermediate posts 43 secured thereto by cap screws 44. Plate 4| is rigidly secured to bushings 38 and 33 by means of nuts 45.

From the foregoing disclosure it is apparent that all that is necessary to secure complete accessibility of the interlock mechanism is to remove closure I and its associated lock barrels; remove collars 36 and 31: and unscrew bushings 34 and 35, which permits the entire interlock mechanism to be dropped down and removed from casing II] by way of one of the plugged openings.

Referring now to Figures 1 and 3, shafts 32 and 33 rigidly carry ratchet discs 41 and 48 at their lower ends, which respectively cooperate with pawls 49. The latter are pivoted on the under side of plate 4| and are urged into engagement with notches 50 in their ratchet discs by tension springs 5|. The pawl and ratchet assemblies accordingly effectively prevent counter-clockwise e rotation of the barrels, as viewed in Figure 3. Rigidly secured to the underside of discs 4? and 48, by rivets or the like are interlock discs 52 and 53 having notches 54 and 55 in their peripheries. As seen in Figure 3, the periphery of disc 52 is received in notch 55 of disc 53, with the result that rocking movements of shaft 33 in either direction is prevented. Y

Operation of the parts is further controlled by a solenoid 51 carried by a downwardly extending bracket 58 from plate 4| and having a plunger 59 coacting with a single opening 8| (Fig. 3) in disc 52 carried by shaft 32. The plunger is normally urged upwardly by a spring 62, so that when the solenoid is deenergized, plunger 53 will be projected by the spring into opening 6| upon rotation of shaft 32 through an angular distance of 90 in a clockwise direction from the position of the parts illustrated in Figure 3.

Also coacting with plate 52 is a micro-switch 64 carried by a depending bracket 65 carried by plate 4| and provided with an actuating arm 65, which is spring-urged upwardly and carries a roller 61 at its free end. The roller coacts with a cam 68 secured to the underside of disc 52. As

seen in Figure 3, cam 68 is provided with inclined.

end or ramp portions, and extends over an angular distance of approximately 90 around the disc. The micro-switch may be of any wellknown character and is operable to open a timer control circuit (to be hereinafter described) when it is depressed, and to close the circuit when it is disposed in its upper position shown in Figure 2. The ratchet and interlock disc assemblies are secured to their respective shafts by nuts 1| and 12, and suitable keying means being employed to insure unitary rotation.

Taking up the operation of the structure so far described, it is to be understood that the parts are shown in the initia1 or starting position in all the figures. Keys 22 and 23 cooperate with their lock barrel assemblies in such manner that they can be inserted and rotated through 360 and then released, the keys and lock barrels embody coacting projections which prevent removal in any other position, as is well understood in the art.

In the position shown in Figure 3, key 23 has been rotated 180 from its insertion position and therefore is held against removal. Key 22 is disposed in removal position and will be assumed to have just been inserted in the apparatus. Pawl 49 prevents counter-clockwise rotation of the assembly with which key 22 is associated, and therefore the only movement possible is clockwise rotation. Upon clockwise rotation of key 22 through approximately 90, plunger 59 is projected by spring 62 into opening 5| of plate 52, thereby locking the key against further rotation. Coincidental with rotating key 22 through 90, cam 68 engages roller 61 and depresses arm 65 of micro-switch 64 into circuit-breaking condition.

Upon conclusion of the foregoing operation, the parts are locked against further manipulation until solenoid 51 is energized, inasmuch as the notch in disc 53 prevents rotation of key 23 in either direction and plunger 59 locks key 22 against rotation. Both keys are therefore retained.

Any suitable form of timer mechanism may be incorporated with the device to introduce a defi-- by a motor 19, so that when micro-switch 54 is."

opened, coil 18 releases the clutch and couples motor 79 to the timer mechanism, whereupon the timing cycle is initiated. The other side of the line 11 leads to a binding post 8|, to which a lead 82 from coil 18 and motor 19 is connected.

Upon engagement of the jaw clutch in. the

manner just described, it causes a contact as sembly 83 to close, and this action, through leads 84 and 85 and a binding post 86, closes the motor,

circuit. A contact assembly 8'! closes the circuit through an indicator light 88 while the timer is in operation, to give a visible indication that the timing operation of the apparatus is in progress.

At the end of the timing interval, contact assembly 81 engages its opposite contact 85, extinguishing light 88 and energizing solenoid 51 through lines 9| and 92. Upon retraction of solenoid plunger 59 in the manner just described, key 22 is released for further clockwise rotation but is held against counter-clockwise rotation by pawl 49. Accordingly, upon rotation of key 22 through an additional 90 travel, from the starting position) notch 54 of plate 52 is brought opposite plate 53, with the result that key 23 may now be rotated 180 clockwise and removedand employed to carry out some other phase of operation in the particular interlock-controlled system.

During the foregoing additional 90 rotation of key 22, cam 68 is so rotated as to allow roller 61 to roll off of its trailing end, restoring arm 55 to the circuit-making position shown in Figure 2, whereupon clutch coil 18 is re-energized, disengaging the clutch and stopping the timer mo tor. This action also returns contact arm 67 to the midposition shown in Figure l, thereby dc energizing the solenoid and resetting the timer for the next cycle. When this occurs, spring 62 projects plunger 59 into engagement with the underside of disc 52.

It should be observed that upon conclusion of the operation just described, the parts are disposed 180 from the positions shown in Figure 3, with the periphery of disc 53 received in notch 54 of disc 52, with the result that the latter cannot be rotated in either direction.

Upon reinsertion of key 23 in look barrel 2|, and rotation thereof through 180", disc 53 is restored to the position shown in Figure 3. Since this places notch 55 adjacent disc 52, the latter may now be rotated 180 clockwise, and key 22 removed. This final step restores the parts to the starting position, and after key 22 has been reinserted the cycle may be repeated.

It is accordingly apparent that the invention provides a pair of rotatable key-receiving devices which are so interlocked that one key is freely insertable and removable while the other is held against removal, and that means are provided whereby the inserted key, when rotated less than a full revolution, will be locked against further rotation until a predetermined time interval has elapsed, and that at the end of that period it may be rotated a further distance sufiicient to permit removal of the other key, resulting in a mechanism which makes it possible to establish a predetermined sequence of locking and interlocking operations requiring the use of a set of keys, thereby eliminating the need of human supervision in a system embodying key-controlled units.

The foregoing embodiment of the invention provides a single timed period of key retention, and therefore is termed a single timer interlock. The invention also may be embodied in the form of a multiple timer interlock, as further described and illustrated in my aforesaid application No. 543,187.

Inasmuch as it is impossible to rotate the parts during normal operation into such position as to permit simultaneous removal or insertion of both of the keys, it is necessary, when initially assembling the device, to rotate the keys into their desired relative positions prior to installing cover I5 on casing l4. Durin assembly, shafts 32 and 33 are also manually rotated into the desired predetermined angular relationship. It is then a simple matter to apply couplings 29 and 3| to shafts 32 and 33, and then apply cover I5 to casing M.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced thereby.

What is claimed is:

1. In an interlock apparatus, a casing, a pair of flanged sleeve assemblies projecting through, and rigidly secured to one wall of said casing; a mounting plate disposed in said casing and having a pair of openings aligned with and fitting over the inner ends of said flanged sleeve assemblies; means for directly rigidly securing said plate to said sleeve assemblies, a shaft in each of said sleeve assemblies; means disposed externally of said casing for rotating said shafts; and means carried by said mounting plate for controlling rotation of said shafts.

2. The interlock apparatus defined in claim 1, wherein each of said sleeve assemblies comprises an externally-threaded bushing screwed into an opening in said casin and an internally-threaded bushing threaded over the inner end of said first bushing and having an externally threaded portion of reduced diameter projecting through said mounting plate, and providing a shoulder bearing against said plate; and a nut threaded on said last-named portion and pulling said shoulder into clamping engagement with said mounting plate.

3. In an interlock apparatus, a main casing; an auxiliary casing seating against said main casing; a pair of sleeve assemblies projecting through the neighboring walls of said casing and securing the latter together; a mounting plate disposed in said main casin and rigidly secured to said sleeve assemblies; a shaft rotatable in each of said sleeve assemblies and projecting into said auxiliary casing; a cover secured to said auxiliary casing and carrying means for actuating said shafts; and means carried by said mounting plate for controlling actuation of said shafts.

4. The interlock apparatus defined in claim 3, wherein each of said sleeve assemblies comprises a bushing threaded into a wall of said main casing and having a flange engaging a wall of said auxiliary casing and maintaining the latter in clamping engagement with said main casing.

GEORGE B. THIEME.

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

UNITED STATES PATENTS Number Name Date 537,311 Schade Apr. 9, 1895 1,134,625 Locke Apr. 6, 1915 1,676,971 Weaver July 10, 1928 2,126,333 Kirk Aug. 9, 1938 2,409,762 Jones Oct. 22, 1946 2,437,785 Mucher Mar. 6, 1948

Images