US3539736A - Reciprocable and rotatable switch with the same cams performing both actions - Google Patents

Description

3,539,736 RECIPROCABLE AND ROTATABLE SWITCH WITH THE SAME I M8 6 9 R E M i 0 9 N n w d H mm E F Nov. 10, 1970 Huber? L. Naimer INVENTOR g Ross Attorney United States Patent US. Cl. 200-4 7 Claims ABSTRACT OF THE DISCLOSURE A shaft rotatably and shiftably mounted in a switch housing carries several axially spaced cams which act upon associated switch armatures during both rotary and axial displacement of the shaft to open or close their contacts. An indexing disc secured to the shaft permits its axial displacement in a selected rotary position only.

The present invention relates generally to an electrical switching device comprising at least one cam switch, but preferably including a plurality of coaxially arranged cam switches, the armatures of each cam switch being operated by a longitudinally displaceable driving shaft via cams seated thereon, the cams following the axial movement of the driving shaft inside the switch housing. Switching devices of this kind, which in addition to the cam switches (approximately up to ten and in some cases even more) also contain a notched mechanism and if necessary also auxiliary devices such as repeating switches, special mechanical locks and the like and wherein the individual cam switches as a rule contain not less than two, but usually more, armatures, make it possible to carry out a switching program which is determined by the shape of the cam peripheries controlling these armatures, the relative positions of the cams and the number of armatures provided, as a particular chronological sequence of switching processes whereby it is also possible to utilize the shortcircuiting of certain contacts of different cam switches in addition to other switching steps.

Switching devices of this kind are used for the most varied purposes; one important field of use is the control technique. This particular use makes increasingly high demands upon the structure of the switches, since it is necessary for them to control switching programs, which are becoming more and more complicated, by means of a small compact and inexpensive switch unit.

The present invention shows a way by which a switching device of the type mentioned herein can, by simple means, be so designed as to make it possible to superimpose at least one additional switching program upon the switching program obtainable by rotation of the switch shaft, without any essential change in the structure of the switching device. In accordance with the present invention this is done, in a switching device of the type hereinabove mentioned, in that for each of the axial operating positions which the cams can assume in the housing with respect to the armatures, said cams are provided with control surfaces which become effective when the cams are rotated, in order to carry out respective switching programs in each of these axial positions.

Switching devices of the type upon which the invention is based have already been designed with axially movable shafts, but in those cases this axial mobility of the shaft was only utilized to operate only a single switch provided in addition to the cam switches, the axially operable switch responding solely to such a displacement of the actuating member. The control member of these additional switches is in the shape of a truncated cone which, dependent upon its axial position in relation to armatures associated with Patented Nov. 10, 1970 it, opens these armatures or allows them to assume their closed position, irrespective of the rotary positions assumed by shaft assigned to the cam switches.

In accordance with another proposal it is also known to develop a switching program in one axial position of the switch shaft by means of cams and, in another axial position, to cause a second set of discs to act upon the switch contacts so that, irrespective of the rotary position of the shaft, all of the contacts are maintained closed, but no second switching program is carried out. Moreover, this case involves not a special design of one and the same set of cams, but the adding of switch-closing circular discs to said cams. In the present case the control cams of the cam switches are of such a shape that, dependent upon their axial position in relation to the switch armatures rotation of the switch-driving shaft brings other control surfaces of these cams into action for the purpose of performing another switching sequence. Accordingly, if a switching device of this kind, comprising a plurality of cam switches, is assumed to be in one rotary position, then the cams in at least two different axial positions of the driving shaft present different control surfaces to the armatures, whereupon the switch shaft is brought into one of at least two predetermined axial positions in relation to the stems of the armatures in which position it can be rotated. This axial displacement with subsequent rotary positioning can also be effected by a remote-control or remote-driving device.

In accordance with a special feature of the invention the driving shaft of a switch is provided with an indexing wheel or disc which permits the axial displacement of the driving shaft to be effected in certain rotary positions only, for which purpose it is adapted to interfit with a complementary counter-disc.

For a more detailed description of the invention and the features inherent therein, reference is made to a diagrammatic drawings in which:

FIG. 1 shows a switching device according to the invention with two cam switches for manual operation with the aforementioned indexing wheel, in axial cross section;

FIG. 2 shows a section along the line IIII;

FIG. 3 shows a section along line III-III of FIG. 1; FIGS. 4 and 6 show axial sections through cams as used in switches according to the invention, respectively taken on lines IVIV and VI-VI of FIGS. 3 and 7; and FIGS. 5 and 7 are cross-sectional views respectively taken on lines VV and VII-VII of FIGS. 4 and 6.

Since the basic structure of cam switches of the type involved here is known, the representation in the drawing is restricted to the essential features of the invention; the drawing must be evaluated with this restriction in mind. The switching device shown in FIG. 1 consists of two cam switches, each composed of a lower housing portion 1 and a cover portion 2. A driving shaft 3 is common to both switches and carrier cams 4 acting upon stems 5 which carry at their ends armatures 6 which are pressed against fixed counter-contacts 8 by means of biasing springs 7. The counter-contacts form connecting leads 8a secured to terminal screws (not shown) which in the customary manner are accommodated, in the practical realization of these switches, inside the periphery of the housing and in recesses thereof. In the embodiment shown, as may be seen in FIG. 2, each switch contains two armatures 6. The driving shaft 3 is connected for joint rotation and axially shifting with its cams 4; at the top end it carries a toothed plate or indexing disc 10, for the purpose of which will be described further on, and a control knob 11. The driving shaft 3 with its cams 4, the toothed plate 10 and the control knob 11 form one unit which is journaled and longitudinally displaceable inside the housing parts 1, 2 and is axially loaded by pressure springs 12 which are clamped between the bottom of housing part 1 I and respective flanges arranged on the undersides of cams 4.

A counter-plate 14 is interlockingly engageable by the toothed plate 10. The counter-plate 14 is pressed by a part 15 with its flange 1411 against the cover 2 of the upper cam switch so that it cannot rotate.

The whole arrangement is held together axially in known manner by mounting bolts 16.

From FIGS. 1 and 2 it will be seen that, by turning knob 11, the cams 4 can be jointly rotated. The armatures 6, originally in their closed position, are opened since the cam-ming edges 4a are moved past the tips of the stems 5 which are radially guided in projections 2a of the cover 2. This interrupts the current path. This corresponds to the well-known mode of operation of a switching device composed of several cam switches.

The cams 4 also have flanks 4b which become effective when the cams are axially displaced. If, therefore, the knob 11 of FIG. 1 is pressed down with compression of springs 12, these flanks engage the stems 5 to reverse (i.e. open) the corresponding armature contacts.

In order to establish a rotary indexed position of knob 11 for the axial displacement of the driving shaft,,which is necessary for many purposes, the embodiment shown uses the locking disc in conjunction with the counteraxial displacement whereas control surface 20b does not.

In practice, the loading springs 12, in order to save overall height, are not arranged coaxial with driving shaft 3 but laterally thereof, approximately midway between bolts 16 and symmetrically duplicated. For this purpose a supporting plate 22, FIGS. 1 and 2 is placed on cam 4 and has projecting extremities upon which these loading springs may bear at 23 on being inserted between these extremities and the bottom of housing 1.

While I have described my invention in terms of a switching device consisting of two aligned cam switches each with two armatures, the invention obviously can also be realized with a single cam switch.

I claim:

1. An electrical switching device comprises a housing; a shaft rotatable and axially shiftable in said housing; contact means in said housing including a plurality of armatures arrayed about said shaft, said armatures being independently movble between a closed and an open position; cam means on said shaft having first working surfaces effective upon rotation and second working surfaces effective upon axial shifting for moving said armatures from one position to the other position thereof; and

1 biasing means urging said armatures into said one posidisc 14. The locking disc has two projections 10a, FIG.

2, and the counter-disc 14 has corresponding recesses 14al Thus, axial displacement of locking disc 10 in relation to counter-disc 14 is possible only in the rotary position of the switch shown in FIG. 2. Of course, this principle can be realized in many different ways.

By the choice of suitably shaped cams, which of course need not be identical in the individual switches, by fixing a particular rotary indexed position of the knob 11 and thus of the driving shaft 3, in which axial displacement is possible, and finally by the selection of certain cams provided with inclined surfaces 4b (which, in the embodiment shown, open the armatures 6 upon downward shifting but of course could also be designed so as to close previously opened armatures upon such movement) it is thus possible to handle two switching programs in the same switching device, one being effected by a rotation of the shaft and the other by the shifting of the shaft.

The two switching programs and their chronological sequence of chronological intercalation, therefore depend not only upon the number of cam switches and the number of armatures thereof but also upon the shape of cams 4, the shape of locking disc 10 the shape of the counterdisc 14 and the extent of the possible axial displacement of the driving shaft 3; the following are a few simple examples:

In FIG. 2 the cam 4 has a further, third recess indicated in dotted lines which, for example, could go right through, i.e. without any beveled flank 4b so as to operate independently of any axial displacement of the driving shaft.

Cam 18 in FIGS. 4 and 5 has three working surfaces A, B and C, which however are not alike. In this case the driving shaft would have to be capable of occupying three levels and adapted also to be rotated in these positions; accordingly, two or three indexing discs could be provided with corresponding counter-discs. This idea could be further developed in that the driving shaft carries out a sequence of programmed upward and forward movements during rotation by means of these control discs.

In FIGS. 6 and 7 there is shown an asymmetrical cam 20 operating on two levels; control surface 20a acts during tion thereof.

2. A switching device as defined in claim 1, further comprising co-operating indexing elements coupled with said shaft and said housing for permitting axial shifting of said shaft in a selected rotary position only.

3. A switching device as defined in claim 2 wherein said indexing elements are a pair of discs with mating peripheral formations.

4. A switching device as defined in claim 3, further comprising axially effective loading means tending to maintain said discs in a disaligned position.

5. A switching device as defined in claim 1 wherein said armatures have stems guided in said housing for substantially radial motion relative to said shaft, said stems having tips engageable by said first and second surfaces.

6. A switching device as defined in claim 5 wherein said cam means comprises a body with a plurality of peripherally spaced recesses bounded by said first and second surfaces, the spacing of said recesses corresponding to that of said armatures whereby the latter are concurrently movable by a displacement of said shaft.

7. A switching device as defined in claim 6 wherein at least one of said recesses is axially bounded by one of said second surfaces and peripherally bracketed by two of said first surfaces.

References Cited UNITED STATES PATENTS 2,603,725 7/ 1952 Dietrich 2004 X 2,676,235 4/1954 Kennedy et al. 2004 X 2,695,339 11/1954 Williams 200-4 X 3,188,678 6/1965 Mandy et al 200-4 X FOREIGN PATENTS 908,443 4/1946 France. 1,109,762 6/ 1961 Germany. 1,230,980 12/ 1966 Germany.

ROBERT K. SCHAEFER, Primary Examiner R. A. VANDERHYE, Assistant Examiner U.o. Cl. X.R. 200-453

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