US2155594A

US2155594A - Electric switch indexing mechanism

Info

Publication number: US2155594A
Application number: US146620A
Authority: US
Inventors: Hart George Hegeman
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-02-06
Filing date: 1937-06-05
Publication date: 1939-04-25
Anticipated expiration: 1956-04-25

Description

April 25, 1939. G. H. HART ELECTRIC SWITCH INDEXING MECHANISM Filed June 5, 1937 III) g'ywa rvloc GEORGE fiQUEM NEQRT Patented Apr. 25, 1939 UNITED STATES PATENT A omen 7 Claims.

switches of the so-called slow make and break\ type andhaving an operating spindle provided pressed members engaging against the periphery oi the plate; the arrangement being such that when the star wheel is turned, the spring pressed members ride up the lobes, and when the'apexesof the lobes pass the spring pressed membels,

the latter ride into the recess between the lobes.

It is the aim of the present invention to provide certain improvements over this type of indexing mechanism and more particularly to provide an improved arrangement which will give the operator more or less the feel of a snap action such as is present in so-called snap actionswitches to assure him that the switch has'been shifted to a desired position. My improved indexing mechanism is rendered more positive in its operation; there being a pronounced. click when the switch is brought to its indexed posi- 80 ti'ons, and sticking of the switch in intermediate positions is avoided.

It is a further aim of the invention to provide,

in a switch of the character described, an improved arrangement through which the cant;

85 carried by the switch spindle operate the swi A further object of this invention resides in the provision of an electrical switch of the type described having various features of novelty and advantage and'which is particularly characterized by its simplicity of construction, ease of assembly, economy of manufacture, and efliciency of operation.

Other objects will be in part obvious part pointed out more in detail hereinafte The invention accordingly consists in the fea I tures of construction, combination of elements and arrangement of parts which will be exempliin the construction hereafter set forth and the"scope of the application of whicli wlll be indicatedinthe appended claims.

Figure 1 is a longitudinal section through the switch showing its operating parts," a

(01. 14-521) This invention relates generally to electric Fig. 2 is a cross section taken substantially along the line 2-2 of Fig. 1;

Fig. 3 is a cross section taken substantially along the line 3-3 of Fig. 1;

Fig. 4 is a bottom fragmentary view of the 3 switch; and

Figs. 5, 6, and '7 are enlarged fragmentary views taken substantially along the line H of Fig; 1 and showing successive positions of the indexing mechanism while the switch is being 10 shifted.

In accordance with this invention, there has been provided an electric switch having an operating spindle Ill rotatable in either direction to successive restpositions for operating one or 13 more switch arms which are arranged to make and break desired circuits. The switch includes an indexing mechanism having a plurality of cooperating indexing cams 'or plates mounted on the spindle and engaged by splingpressed balls 20 or similar members which locate the switch in its operative or rest positions and oppose the initial spindle movement froinone rest position to a successive rest position. After a predetermined initial spindle movement as controlled by 15 a suitable operating menmer or handle, the indexing mechanism will cooperate with the handle to hasten the shaft rotation to the successive rest position and complete the spindle movement.

Referring to the drawing, there has been pro vided a casing I! of suitable insulating material and having side walls I and I1 interconnected by a rear wall II and a bottom wall IS. The side walls and rear wall extend below the bottom wall, and a short front wall 20 it provided ,3

, forming a cavity 20' on the under side of the switch within which are one or more switch arms. A cover 2|of suitable insulating material is secured in the outer end of this cavity, as by screws, to protect the switch arms within the cavity and provide access thereto. In the present showing, there is provided three

switch arms

22, 23, and 2! which are respectively operated' by tappets 22'. 23', and. 24' slidably mounted for free axial movement within bores passing through bottom wall ll adjacent the switch arms. The tappets are supported by the-J switch arms and operated by cams, as will be later described. The inner ends of the switch arms are rigidly secured to terminal plats 25 mounted on the casing and having screws 25' to facilitate electrical in a-circuit. me free outer -.end ofeach switch min; a suitable contact 1point-Premova'bly engageable withaslmiiar contact point P on asuitable terminal plate 28 secured'to the casing and having connection screws 26'. In the present instance, the switch arms are shown as being inherently resilient and normally tending to assume closed circuit positions with the contact points in electrical engagement. However, it will be evident that the switch arms may be spring urged into closed positions in various other ways without deviating from the scope of the present invention. It will be fur- -ably received within rabbeted portions of easing l and secured in position as by screws passing through the cover into rear wall l8 and as by screws passing through a bent over vlip 28" at the lower end of the front wall and into threaded holes 30 in the casing.

rigidly secured to the shaft with their corresponding lobes and depressed portions in alignment. Intermediate plate 44 is generally similar in contour to plates 42 and 43 with the exception that the lobes 441 corresponding to lobes 42' are somewhat larger and of slightly greater radial extent from the axis of spindle III. Plate 44 has depressed portions 44' similarly spaced to depressions 42" and at the same radial distance from the axis of spindle ID. This intermediate" plate is lost motion connected to the index member (in the present instance, plate 43) as by pins 46 laterally projectingfrom plate 43 and received in arcuate slots 46' in plate 44. These slots are concentric with the spindle and permit a slight amount ofrotary lost motion movement of the intermediate plate with respect to the plates at each side thereof. After the completion of this slight lost motion, all of the plates are constrained to rotate together as a unit.

" A pair of spring pressed balls 48 received within opposed tubularportions 43 of a housing 50 'are resiliently urged, as by springs 5|, into Spindle Ill which operates the switch mechanism is journalled at its forward end in a bearing 3| supported by the front cover wall 28' and at its rearward end in a bracket 33 depending from and secured to top wall 28. Hence, the spindle and cam assembly and an indexing mechanism, to be later described, is removable as a unit with the cover to facilitate assembly and accessibility to the various switch parts.

Bearing 3| projects forwardly from cover 2l and has external threads 3| receiving a nut3l" so that-the switch may be conveniently secured to a wall or panel in a single hole type of mounting. Spindle I0 extends forwardly from hearing 3| and has a suitable insulating handle 34 fastened thereon, as by a screw 35.

The tappets are respectively engaged and depressed by cams on spindle It! so that rotation of the spindle to predetermined rest positions will operate the switch and-establish desired circuits. In the present showing, there are provided three cams 22.", 23", and 24" rigidly secured to the spindle in spaced relation and respectively engageable with the tappets 22, 23, and 24 to control the o'peningand closing movements of the switch arms '22, 23, and 24. Each tappet has a partispherical head to facilitate a and . ties of opposed lobes 4.4 engage balls 43, as shown.

tween plates 42 and 43. In the present instance,

theswitch is shown as having four operative positions so thatthe plates are each-provided with four lobes and depressed portions respectively located between each pair of lobes: It

I will be-appreciated, however; that the number of lobes and depressions on each plate is de- 7 pendent solely on the number of positions to which the switch is to be shifted.

Plates 42 and 43, which have uniformly spaced duplicate symmetrical lobes 42' and. uniformly simultaneous opposed engagement with the plate contours, as shown in Figs.5, 6, and 7. Housing 50, which may be suitably formed from metal bent to shape and secured to front wall 23', is centrally apertured to freely receive spindle I 0 therethrough and to permit rotation of the'index plates. The ends of the tubular portions are provided with bent over cars 52 arranged to compressively secure the balls and spring assemblies in position. Since the depressed portions of the index plates are ofcorresponding size and correspondingly located, it will be appreciated that.

under normal conditions the balls will, be received inopposed relation in similar depressed portions of each plate to secure the switch in its preset position.

When the spindle I3 is rotated in'elther direction, herein illustrated in a clockwise.direction, plates 42 and 43 will integrally rotate with the spindle and the initial rotation of plate 44 will be retarded by the. spring pressed engagement of the balls thereagainst. The peripheral contours of the, lobes 44' are such that when the lost motion has been taken up by pins 46 within slots, 46' (Fig. 7) lobes 44' will in effect constitute a smooth peripheral continuation of that portion of the lobes 42' engaged'bythe spring pressed balls, causing the balls to ride past and out of contact with lobes, 42'. Hence, the initial rotational movement of spindle Ill and the index plates under'influence of handle 34 will store up energy in springs 5| until the radial extremiin Fig.- 7. Further movement of spindle ID in the same direction will now cause the balls to ride downwardly on the other sides of the lobes 44f and into seated engagement with the next su':cee'dlng set of depressed portions to a positipn similar to that of Fig. 5 to again locate the switch in a rest position. The intermediatejtation after the balls ,move over the radial extremities of the lobes 44', resulting in a snapping actionrwhich produces an audible click and is felt by the operator to signal to him that the switch has shifted to the succeeding rest position;

It will thus be appreciated that the index spaced duplicate depressed portions 42", are plates cooperate with each other and with handle N to introduce a positive operation of the switch and to definitely position the switch when the handle is turned to shift the switch to its succeeding rest position. The switch cannot stick in an intermediate position of its movement since the plates 43 and 4d are lost motion connected and the lobe of each plate has sharply sloping contours meeting at a point. Hence, the balls 48 will always tend to seat in depressed positions of the plates. Furthermore, the provision of tappets slidably mounted in the casing and engageable with the switch arms provides a substantial straight line movement of switch operation without producing undesirable wear or friction frequently found in other types of switches.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention'could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is. also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of member, and a member resiliently urged against the perimeters of said plates.

2. In an electric switch, indexing means comprising a rotary operating member, index plates on said spindle having similarly positioned spaced lobes and depressed portions, one of said plates having limited rotary movement with respect to another of said plates fixed to said member, the lobes of said, first plate extending beyond the corresponding lobes of said second plate, and a member resiliently urged against said plate contours and normally seating within corresponding depressed portions of said plate to position the switch in indexed positions.

3. In an electric switch, indexing means comprising, a spindle rotatable in both directions, means responsive to the spindle rotation to operate the switch arm, an inde'x plate rigidly secured tothe spindle and having a plurality of spaced lobes and depressed portions, a. second plate generally similar in contour to the first plate and journalled on the spindle adjacent thereto, a lost motion connection between said plates, the lobes of said second plate radially extending beyond the lobes of the firstlplate, and a spring pressed member engageable with the contours of said plates whereby the lobes 01' Said tion between the plates plates will cooperate with said member to aid in rotating the spindle to successive predetermined positions after an initial spindle movement.

prising a'spindle rotatable in either direction to predetermined positions, adjacent generally similar indexplates on said spindle and having similarly positioned spaced lobes and depressed portions,- one of the plates being freely rotatable and the otherbeingirigidly secured to the spindle, one of said plates -t having an aperture therethrough receiving a pin laterally projecting from the other plate to providaa lost'motion connecsaid freely rotatable plate having lobes exten ing beyond the corresponding lobes of the other plate, and a spring pressed member engageable with the peripheries of said plates.

5. In an electric switch, indexing means comsecond plate, and a spring pressed ball engage able with the peripheries of the plates. 6. In an electric switch, indexing means comprising an-operating splndle rotatable to predetermined positions, a pair of adjacent index plates on the spindle and of generally similar contour, one of said plates being freely rotatable and lost motion connected to the other which is rigidly secured to thespindle, each plate having uniformly spaced lobes and intervening depressed portions, said first plate having its lobes radially extending beyond the corresponding lobes of said second plate, and a spring pressed member engageable with the plate peripheries, the contours of corresponding lobes engaged by the member being such that the contour of the engaged lobe of the first plate will serve as a continuation of the corresponding contour on the second plate.

7. In an electric switch, indexing-means comprising an operating spindle rotatable in either direction to predetermined' positions, a pair of fixed spacedindex plates onthe spindle and having duplicate aligned peripheral contours provided with uniformly spaced lobes and intervening depressed portions, an intemediate plate of generally similar peripheral contour lournalled on the spindle between said other plates and lost motion connected to one of said other plates and having lobes radially extending beyond the'corresponding lobes of said other plates, and a spring pressed ball engageable with the plate contours, the contour of thedntermedlate plate engaged bythe ball merging with and serving as a continuation of the corresponding contour of said other plates after the intermediate plate has been shifted to its lost motion position.

GEORGE HEGEMAN HART.