US1670073A - Rotary snap switch - Google Patents

Description

May 15, 1928.,

| A. KEMPTON ROTARY -S NAP SWI TCH Filed Dec.l6, 192s Inventor-1 Leslie -A.Kem oton,

His Attorhe y. K

Patented May 15, 1928.

UNITED STATES LESLIE A. narrow, or nnmearoar, CONNECTICUT, ass'renoa r0 -comrm,- A coaroaarron or NEW YORK.

GENERAL ELECTRIC ROTARY SNAP SWITCH.

Application filed December 16, 1926. Serial No. 155,260.

The present invention relates to electric switches, and-more especially to rotar snap Switches adapted to be actuated in eit er direction of rotation.

The object of my invention is the pro-- vision of an improved rotary snap switch which shall be of strong and sturdy construction, well adapted to withstand the severe hammer blow stresses incident to the normal operation thereof and which may be economically manufactured.

One embodiment of the invention is shown in the accompanying drawing, in which Fig.

' 1 is an axial section of a complete switch;

Fig. 2 is a plan view of the base and metal parts mounted thereon; Figs. 3 and t are axial sections of the actuating handle with the parts showing in normal and displaced relation; Fig. 5 is a plan view of the movable switch member; Fig. 6 is an exploded perspective view of the parts of the handle; Fig. 7 is a similar .view of the parts for mounting the ratchet pawl upon the movable switch member; Fig. 8 is a perspect1ve'v1ew of the'parts of Fig. 7 in assembled relatlon; and Fig. 9 is a top plan view of the same.

The switch as shown in the drawing is designed to control electric heater circults,

' and is known in the art as a three heat reversible switch. The base 1 is of moulded insulating material having embedded therein a stop-plate 2 of sheet steel-withfo ir spaced stop projections '3 formed by dlsplacing upward sections of metal, each at the juncture of two slots disposed at right angles, while symmetrically disposed with relation'tothe stop projectlons 3 in a metal hub 4 which extends through the base and provides a fixed bearing in which is journalled the switch shaft 5 having near one end pairs ofnotches formed in opposite sides for the reception of a slotted washer 6 and a slotted cam 7 which bear against opposite ends of the hub 4 and hold the shaft against axial displacement. Stationary contacts 8, 9, 10. and 11 are mounted at distributed points on the base and secured thereto by set screws 12 in the usual manner. l

The movable member of the switch comprises a set of switch blades 13 and 14 of phosphor bronze or other sheet metal wlth their centers cut out and mounted upon polygonal blocks of insulation 15 with intervening barrier disks 16. The blocks 15 and disks 16 are mounted upon a polygonal metal hub 17, which is bored out axially and journalled upon the shaft 5, whereby the 'shaft is permitted to turn freely therein during the tensioning of thesnap spring and while the movable switch member is held from turning by the pawl or detent 18 in engagement with some one of the stop provjections 3.

.hub 17. In order positively to anchor the crank plate to the hub 17 so that it may not work loose under the hammer blows incident to the sudden stopping of the momentum of the movable switch member first in one directlon and then in the other, -I provide an anchor plate 23 of heavy sheet metal havto fit very tightly about the end of the polyge onal hub .17 while at opposite oints in the outer edge are two notches 25 f dr the reception of corresponding bent up lugs 26 on the crank plate 22.

- After these parts of themovable switch member have been assembled upon the hub 17 a metal washer'27 is placed on top and riveted to the hub. The washer 27 has a bent up spring engaging crank arm 28. A. second washer 29 is fixed to the shaft 5 just above the washer 27 and has a spring en- \end of the keyhole until the side notches 31 are brought into the plane of the washer and v8O mg a central aperture 24 of a shape and slze then by a sidewise shift of the latter it is secured against relative rotation therein and to prevent it from backing off sidewise I provide an integral lug adjacent the large end of the keyhole which is bent down thercin after assembly of the washer on the shaft.

The snap spring 34 is shaped into two coIu-entric helices with the free ends 35 there of extended radially outward into engagement with thebent up arms 28 and 30. In orderto hold the spring in proper position radially and'axially of the shaft, I provide a spider 36 consisting of a washer with a. plurality of arms 37 struck up therein and spaced to enter the inner helix of the spring while its center is apertured to fit the shaft 5.

It is detachably held in place by a slotted washer 38.

The switch mechanism is enclosed by an insulatively lined metal shell-39 and through its top the free end of the shaft 5 projects for the reception of the actuating handle 40, which for proper functioning must be adapted to turn the switch in either direction and also yieldingly to hold the enclosing shell 39 pressed against the base. A chafe plate sides with two extensions to serve as guide.

ways 43 for the reception of lugs 44 on the retaining nut 45 by which the handle is secured to the shaft. The nut 45 is yieldingly pressed inwardly of the cavity 42 by a cone shaped helical spring 46 which surrounds the shaft and thrusts against a. keyhole lockingdisk 47 secured against a shoulder 48 in the cavityby a spring hoop 49 snapped into an annular groove adjacent said shoul der 48. The keyhole of thedisk 47 is shaped to permit it to slide freely over the end of the shaft 5 and the lug or feather 50 struck up therein, and the disk is provided at opposite edges with lugs 51 adapted to enter the guide ways 43, whereby it is positively prevented from turning relative to the handle 40. a

The parts of the handle and shaft con necting means are shown in their normal positions in Fig. 1 with the keyhole disk 47 engaged by the lug or feather 50 on the shaft. In'order to remove the handle, it is only necessary to pull upon it axially of the shaft against the tension of the spring '46 sufficiently for the keyhole disk 47 to clear the outer end of the feather 50, whereupon it may be turned backhandedly and the nut 45 unscrewed from the shaft in well known manner.

WVhile I have shown and described the best embodiment of the invention known to me, I do not desire to be restricted thereto.

\Vhat I claim as new and desire to secure by Letters Patent of the United States is:

1. In a snap switch, the combination with a base having a stop plat'e mounted thereon, of a movable pole piece provided with a hub, a shaft extendin through said hub and journalled in sai base, a cam carried by said shaft, a detent movable into and out of engagement with said stop plate by said;

cam, a crank plate mounted .on said hub and operatively connected to said detent, and an anchor plate securely fixed upon said hub and having shouldered engagement with said crank plate.

2. In a snap switch, the combination with a base having a struck up stop plate mounted thereon, of a movablepole piece having a polygonal metal hub, a shaft extending axially through said hub andjournalled in said base, a spring operatively connecting said movable polepiece and said shaft, a cam fixed to said shaft, a detent movableinto and out of engagement with said stop plate by said cam, a'crank plate slidably engaging said detent, and means for positively securing said crank plate to said, movable pole piece comprising an anchor plate locked at its periphery to said crank plate and out out at the center for a driving fit with said poly onal metal hub.

3. na snap switch, the combination with a base having a stop plate mounted thereon,

of a movable pole piece having a square metal hub, a shaft extending loosely'through said hub and journalled in said base, a spring operatively connecting said movable pole piece and said shaft, a detent movable by said shaft into and out of engagement with said stop plate, a crank plate slidably connected to said detent and provided with bent up peripheral lugs, and means for se- Curing said crank plate in fixedrela-tion to said square hub comprising an anchor plate having a central aperture adapted to make a driving fit with said hub and in its periphery two opposite notches for the recept on of the bent up lugs.

4. In a snap switch the combination with the actuating shaft and movable pole piece thereof, of crank arms fixed respectively to said shaft and pole piece, a spring for engaging said crank arms comprising two concentric helices, and a spider plate mounted on said shaft over said spring and adapted to retain it in position both radially and axially of the shaft.

5. In a snap switch, the combination with the actuating shaft and movable pole piece thereof, a crank arm disk secured to said Y movable pole piece, said shaft having side notches formed therein adjacent said crank end of said aperture and secured therein by arm disk, a second crank arm disk provided depression of said lug into said larger end with a central keyhole aperture and a bent of said aperture, and a coiled spring adapted 10 up lug adjacent thereto whereby the shaft to engage said crank arms. is adapted to be entered in the larger end In Witness whereof, I have'hereunto set of the keyhole aperture and its slotted porniy hand this 14th day of December, 1926. tion to be entered sidewise into the narrower LESLIE A. KEMPTON.

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