US2797271A - Permutation switch - Google Patents

Description

June 25, 1957 A. L. AUGUSTINE 2,797,271

PERMUTATION swnca Filed March 29, 1954 a vf'g i- 4 3 F 43': n J5 I l 1. 47 31 A17 w E I i a 26 22,115. 33 124 33 ZVALLQE 15 ARTHUR LAUGUST/NE IN V EN TOR.

By SELLERS 2 LATTA, ATTORNEYS.

PERMUTATIQN SWITCH Arthur L. Augustine, North Hollywood, Calif., assignor to Augustinedlavidson Lock Corporation, North Hollywood, (Zalih, a corporation of Washington Application March 29, 1954, Serial No. 419,373

6 Claims. (Cl. 200-43) This invention relates to electrical circuit makers and breakers, and has as its general object to provide a kcyless switch for use in connection with apparatus needing pro tection against theft, said switch being of a character such as to make it extremely difficult for an unauthorized person to close the switch and start the apparatus. The invention is particularly useful as an ignition switch for automotive vehicles and in that respect has as its object to protect such vehicles against theft.

More specifically, the invention relates to the type of switch which may be classified as a permutation switch, wherein a series of rotatable tumblers must be arranged in a predetermined order in order to close the circuit controlled by the switch.

The primary object of the present invention is to provide an improved, simplified, compact and fairly dependable and durable electric switch of the permutation type.

Other objects will become apparent in the ensuing specifications and appended drawings in which:

Fig. 1 is a longitudinal sectional view of a switch embodying the invention;

Fig. 2 is an end view thereof with a major portion of the rear end plate removed to expose the internal construction.

As an example of one form in which the invention may be embodied, I have shown in the drawing a permutation switch including a case having a mounting flange 11 which may bear against the forward side of a mounting panel 12, such as the instrument panel of an automobile. Case 13 has a removable rear cap or cover 13 and a forward end member 14. The case 10 may be secured to panel 12 by means of bolts extended through notches 15 in end cap 13, through case 13 from end to end thereof, and through front end member 14 and panel 12. Case 10 is provided with a central boss 16 in which is securely mounted a reduced end portion of a tumbler supporting sleeve 17. Rotatably mounted within a cylindrical axial bore in sleeve 17 is an actuator shaft 18, which may extend outwardly through an aperture in panel 14, and which at its forward end carries a dial knob 19. Dial knob 19 may have a hub portion 20 secured to shaft 18 as by means of a set screw 21 threaded through hub 21 and engaged against shaft 18. Knob 19 may have a collar flange 19' provided with numbered indicator marks cooperable With an indicator mark on a dial 22 which may be mounted on panel 12.

Rotatably mounted upon sleeve 17 are a series of tumblers 23, 24, 25, 26, each having a cylindrical annular hub portion 27 provided with a cylindrical bore which receives sleeve 17. Tumblers 23-26 each includes a flat radial web portion 28 and a cylindrical rim portion 29, web 28 being at one side of the disc and hub 27 and rim 29 projecting, in opposed, coaxial, radially spaced relation to the other side thereof and to the same extent.- Thus each of the tumblers 23-26 is in eifect a relatively thick, flat disc with an annular recess 30 therein, opening into one side thereof. The tumblers 23-26 are of electrical insulating material and are preferably of a synthetic resin plastic material, injection moulded. A relatively rigid, form retaining material is utilized, a suitable material being a phenolic aldehyde resin, although any resin, sufiiciently unplasticized and having suitable insulating properties, can be employed. Other suitable materials are hard rubber, a high strength ceramic material, or a metal casing or stamping, adequately coated with a coating of insulating material.

.Each of the tumblers 23-26 has a pair of integral, axially extending fingers 31 and 32, the latter projecting integrally from web 28 into the annular recess 30 of the respective tumbler and, the former projecting outwardly from the opposite side of web 28. Fingers 31 and 32, being coaxial for each individual tumbler, are arranged substantially at a common radius from the axis of shaft 13 and thus are adapted to inter-engage between adjacent tumblers, the finger 31 of one tumbler projecting into the annular recess 30 of an adjoining tumbler. Thus the tumblers may be arranged quite compactly with only slight axial spacing between their rims 29, as determined by separator washers 33 interposed between adjacent tumblers and encircling and piloted upon sleeve 17.

The finger 31 of the rearmost tumbler 26 projects rearwardly beyond the tumbler assembly for engagement with an actuator arm 34 which is secured to shaft 18, as by means of a set screw 35 extending through an annular hub portion 36 thereof.

Each of the tumblers 23-26 has in its rim 29 an axially extending, shallow rectangular recess in which is mounted a bus-bar 37, the outer face of which is flush with and constitutes a continuation of the periphery of rim 29. As indicated in the sectional View of tumbler 23 in Fig. l, the bus-bar 37 extends the full axial width of the respective tumbler rim.

To establish an electric circuit through the switch, busbars 37 must be lined up so as to be bridged by a series of brushes 3%, 39, 4d, 41 and 42, each of which is of bifurcated form, including legs 43 and 43' adapted to bridge adjoining tumblers, with the leg 43 riding on the rim 29 of one tumbler at one side thereof and the leg 43' riding on the rim 29 of the adjacent tumbler at the other side thereof. Thus, the brush 39 bridges tumblers 23 and 24, brush 40 bridges tumblers 24 and 25, and brush 41 bridges tumblers 25 and 26. Brush 38 has its blade 43' riding on the periphery of tumbler 23 and its blade 43 connected to a conductor 46. Brush 42 has its leg 43 riding on the periphery of tumbler 29 and its leg 43' connected to a conductor wire 45. Conductors 45 and 46 extend through an insulator grommet 47 in rear cover 13, and are adapted to be connected into the ignition circuit of the vehicle in such a manner that when bus-bars 37 are lined up so as to be all in contact with brushes 38-42, a circuit will be completed between conductors 45 and 46. Conductors 45 and 46 are insulation covered wires.

Brushes 38-42 must be normally insulated from one another, and for this purpose the invention provides a novel and relatively simple insulator mounting for these brushes, which mounting serves as a means for arranging the brushes 38-42 in a unit assembly which can be removed or inserted as a unit from or into the case ltland which, when inserted in the case will provide forproper location of the respective brushes with reference to their respective tumblers. To this end, the invention provides a mounting arch 50, of insulating material, of substantially semicylindrical form, the ends of which are adapted to abut against tubular bosses 51 in case 10, one side of each boss projecting into the case to provide an abutment shoulder at 52. Thus the brush mounting arch 50 may when inserted, will be adequately supported by the abut ting engagement of its ends with shoulders 52. Bolts extend through bosses 51. The heads of bolts 15 may be covered by dial 57.

The brushes 42, as viewed in side elevation are roughly Z-shape, each including a web portion 53 having one or more apertures to receive a rivet 54 by means of which the respective brush is secured to the supporting 'arch 50; each including the respective legs 43 and 43 and each having the inner end of each leg bent to provide acurved shoe 55 for riding against the periphery of a respective tumbler, and making electrical contact with the respective bus-bar 37 when the tumbler has been rotated to the proper position. The legs 43, 43 are so dimensioned and formed as to provide for yielding, resilient pressure of shoes 55 against the peripheries of the tumblers, thereby assuring good electrical .contact.

Mounting arch 50 is of a material having suitable insulating qualities; fairly stiff, yet flexible, pro-formed to a slightly greater radius than that of the internal wall of case 10 so that when inserted therein the respective extremities of arch 50 will yieldingly press outwardly against the wall of the casing and thereby securely maintain the end portions of the arch 50 in supported engagement with shoulders 52.

In the operation of the switch, the operator grasps knob 19 in the fingers and rotates it back and forth, bringing various numbered indicator marks 57 on the rim 19 of dial knob 19 successively into registry with a suitable indicator mark 58 on the dial 22. In the initial rotation of the knob it will be rotated several revolutions, so as to cause the fingers 32 of successive tumblers, beginning with tumbler 27, to inter-engage with fingers 31 of adjacent tumblers so that the successive tumblers 25, 24, 23 will in turn be picked up and rotated along with the first tumbler 27. The first stop at the indicator mark will result in the bus-bar 37 of tumbler 23 being brought into contact with the contact shoe 55 of arm 43' of brush 38. The knob is then twirled in the opposite direction, one turn less than previously, causing arm 34 to first disengage from one side of pin 31 of tumbler 26 and rotate around into engagement with the other side of this pin, picking up tumbler 26 and rotating it in the new direction, with the successive tumblers and 24 being similarly picked up and rotated until, at the second stop at the indicator mark, tumbler 29 will be positioned with its bus-bar 37 bridged by brushes and 39 respectively.

The knob is then rotated in the original direction, arm 34 again leaving pin 31 of tumbler 27 and swinging around to the other side of the pin to pick up tumbler 26 and, subsequently, tumbler 25 and rotate the two until busbar 37 of tumbler 25 is bridged by brushes 40 and 41 respectively. Theknob is again reversed and rotated in the second direction, causing tumbler 26 to be rotated to a position where its bus-bar 37 is bridged by brushes 41 and 42. At this point a complete bridging circuit across the series of tumblers is set up and the circuit is closed.

For relocking the switch, the knob 20 is swung back and forth to dislodge the respective tumblers from bridging engagement .with brushes 3942. For most effective scrambling of the positions of the tumblers, the knob is first rotated several turns inalternately opposite directions, through decreasing number of turns, care being taken not to stop aththe position set up for the combination assigned to the particular lock.

Various combinations can be provided for by varying the positions of the respective bus-bars 37 around the rims of the respective tumblers, with relation to transmitting fingers 31 and 32.

One of the important advantages of the invention arises from the arrangement wherein the actuator shaft 18 (live shaft) extends through the sleeve 17 (dead shaft) upon which the tumblers 2326 are rotatably mounted, and wherein the liveshaft 18 carries at one end the actuator knob 19-and at its otherend the actuator finger 34 which constitutes the only point of transmission of rotating movement from the shaft 18 to the tumblers. Being mounted on the sleeve 17 with a substantial area of cylindrical surface in engagement therewith, the tumblers are maintained, by the frictional engagement with sleeve 17, in the positions establishing respective portions of the electric circuit, and after any given tumbler has been adjusted to such position, the rotation of an adjoining tumbler to its respective position does not disturb the tumbler which has already been located. The area of bearing engagement between the cylindrical bores of the tumblers and the sleeve 17 is much larger than the area of bearing engagement between the radial faces of hubs 27 and spacer washer 33, so that the resistance to rotation which is afforded by the former, represents a torque load greatly in excess of the torque force transmitted through a spacer washer. Thus the fixing of each tumbler in its circuit establishing position, resisting any tendency to be dislocated by further rotation of an adjoining tumbler, is completely assured.

The integral moulding of drive fingers 31, 32, with the tumbler bodies provides for relatively inexpensive mass production of the tumblers, all identical in pattern. The construction of the tumblers with side opening grooves 30 receiving the drive fingers 31 of adjoining tumblers makes it possible to arrange the tumblers in closely adjacent relation, with their peripheries completely clear to provide for peripheral association between the bus bars carried thereby and the connector brushes which may thus be carried upon the inner wall of the case. The use of a peripheral arrangement of connector brushes engaging cylindrical peripheries of the tumblers in turn, makes it possible to utilize the axially compact arrangement of tumblers, thus reducing the overall axial dimension of the switch to a minimum. It has the further advantage of making it possible to mount the connector brushes in a unit assembly upon an insulator panel of arcuate form which can he slipped into and out of the case as a unit. This in turn greatly simplifies the construction of the case, which may take the form of a simple cylindrical cup.

I claim:

1. In a permutation switch, a case; a plurality of tumblers of molded insulating material rotatably mounted in said case on a common axis, each of said tumblers having respective hub and rim members defining between them, in one side thereof, an annular recess, and having on the other side thereof a flat radial web integrally joining said hub and rim members and defining the bottom of said recess; each tumbler including a pair of rotation transmitting fingers integral with and projecting in opposite directions from the web thereof, with one of said fingers extending into the annular recess of the respective tumbler and the other projecting externally from the back sideyof said web, said tumblers being arranged with each of said other fingers projecting into the recess of an adjoining tumbler and engageable with said one finger of said adjoining tumbler for lost motion transmission of rotation between adjoining tumblers; a shaft rotatably mounted in said case and extending coaxially through said tumblers, an actuator arm on the rear end of said shaft, engageable with the externally projecting finger of the rearmost tumbler; an actuator part attached to the forward end of said shaft; said casing having at one end an integral end wall through which said sh'aft extends; a dead shaft of cylindrical sleeve form having an end fixed in said end wall and having a free end spaced from the other end of the case, said first mentioned shaft extending through and journalled in said dead shaft and having an end portion projecting beyond said free end of the dead shaft, to which end portion said actuator part is secured, the respective tumbler hubs having cylindrical bores snugly receiving and journalled on the outer wall of said dead shaft; relatively thin spacing washers interposed between the respective tumblers in encircling relation to said dead shaft; a retainer ring secured to the free end of said dead shaft, said tumblers and spacer washers being retained in closely associated array between said retaining ring and said end wall of the case; indicator means for indicating the position of said actuator part; bus-bars each mounted in the rim of a respective tumbler; a plurality of electrical connector brushes bridging between adjacent tumblers and adapted to make electrical contact with said bus-bars for establishing a bridging connection across said tumblers assembly; and means mounting said brushes in the case in electrically insulated relation thereto.

2. A switch as defined in claim 1 wherein said brushes are of bifurcated form, each including a radially outward web portion, a pair of spaced legs projecting inwardly therefrom and contact shoes on the inner ends of the respective legs, said shoes being rounded for smooth riding contact with the peripheries of said tumblers.

3. In a permutation switch, a cylindrical case; a plurality of tumblers rotatably mounted in said case on a common axis; rotation transmitting elements projecting axially in opposite directions from the respective tumblers and interengageable with similar elements of adjacent tumblers for lost motion transmission of rotation between adjoining tumblers; a shaft extending co axially through the tumblers and journalled in said case; means on the inner end of said shaft for lost motion transmission of rotation to the rearmost tumblers; bus-bars mounted in the peripheries of said tumblers; a plurality of electrical connector brushes bridging between adjacent tumblers and adapted to make electrical contact with said bus-bars for establishing a bridging connection across said tumbler assemblies; and means mounting said brushes in the case in electrically insulated relation thereto, said brushes being of bifurcated form, each including a radially outward web portion, a pair of spaced legs projecting inwardly therefrom and contact shoes on the inner ends of the respective legs, said shoes being rounded for smooth riding contact with the peripheries of said tumblers, said case having a cylindrical internal lateral wall, and said insulator means comprising an arched plate mounted against said inner wall, each brush having a web portion thereof attached to the inner face of said arched plate.

4. A switch as defined in claim 3, wherein said case has bosses extending longitudinally in the lateral wall portion thereof and integral therewith, said bosses projecting inwardly of said inner wall of the case, and wherein said arched plate has respective ends abutted against said bosses and its central portion bearing against said inner wall as the sole means for supporting and laterally positioning said arched plate in the case.

5. A switch as defined in claim 3, wherein said case has bosses extending longitudinally in the lateral wall portion thereof and integral therewith, said bosses projecting inwardly of said internal wall of the case, and wherein said arched plate has respective ends abutted against said bosses and its central portion bearing against said internal wall as the sole means for supporting and laterally positioning said arched plate in the case.

6. In a permutation switch: a case of cup shape having an end wall member at one end thereof and having a lateral wall member; a dead shaft of cylindrical sleeve form having one end fixed in said end wall member and having a free end spaced from the other end of the case; a plurality of disc-like tumblers having cylindrical hub bores receiving said dead shaft and rotatable thereon; electric contact elements carried by the respective tumblers; connector brushes mounted in the case and arranged to provide bridging connection between the contact elements of adjoining tumblers; drive elements carried by the respective tumblers and interengageable for lost motion transmission of rotation between the respective tumblers for aligning them in circuit establishing positions, said drive elements including an element projecting externally from a terminal one of said tumblers disposed adjacent the said free end of said dead shaft; a live shaft extending through and rotatable in said dead shaft, and having one end adjacent said free end of the dead shaft; a drive transmitting member secured to one end of the live shaft and positioned for engagement with said externally projecting drive element of said terminal tumbler; an actuator member secured to the other end of said live shaft, for transmitting rotation through the live shaft to said tumblers; said drive transmitting elements projecting axially from the respective tumblers, inwardly of the peripheries thereof, said externally projecting drive element and said live shaft both projecting axially beyond said free end of the dead shaft; said drive transmitting member constituting an arm secured to the said projecting end of said live shaft and extending radially outwardly to a point where its sweep path Will be intercepted by said externally projecting drive element; said tumblers having cylindrical peripheries collectively constituting a common cylindrical outer face of the tumbler assembly, with only slight axial spaces between the respective individual tumbler peripheries; and said contact elements comprising arcuate, plate-like bus-bars mounted in the respective tumbler peripheries and having outer contact faces constituting portions of said cylindrical tumbler periphery.

References Cited in the file of this patent UNITED STATES PATENTS 345,270 Beggs et a1. July 13, 1886 669,295 Wendel Mar. 5, 1901 1,118,024 Lawrence Nov. 24, 1914 1,148,750 Button Aug. 3, 1915 1,515,764 Albert Nov. 18, 1924 1,563,239 Stewman Nov. 24, 1925 1,673,607 Tulloch June 12, 1928 2,010,570 Stein Aug. 6, 1935 2,023,894 Leinenweber Dec. 10, 1935

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