US3012115A - Selector device - Google Patents

Description

Dec. 5, 1961 J. L. BECKNELL ETAL 3,012,115

SELECTOR DEVICE Filed May 25, 1959 2 Sheets-Sheet 1 OFF VACUUM OPERATED Dec. 5, 1961 BECKNELL ETAL 3,012,115

SELECTOR DEVICE Filed May 25, 1959 2 Sheets-Sheet 2 United States Patent 3.012,115 SELECTOR DEVICE James L. Becknell and Donald M. Papa, Milwaukee, Wis., assignors to Cutler-Hammer, Inc., Milwaukee,

Wis., a corporation of Delaware Filed May 25, 1959, Ser. No. 815,708 3 Claims. (Cl. 200-83) This invention relates to a selector device for electric switches.

A primary object of the present invention is to provide an improved manually operable selector device usable with a condition responsive electric switch to afford selectable OE and continuous on operating conditions in addition to its normal condition responsive operation. A still further aim is to provide an improved control means of the aforesaid type which is characterized by simplicity and ruggedness of construction, ease of assembly and installation, and low cost of manufacture.

A more specific object is to provide a selector device of the aforesaid type for use with a switch mechanism of the type disclosed in US. Letters Patent No. 2,781,431, issued February 12, 1957.

Other objects and advantages of the invention will hereinafter appear. I

The accompanying drawings illustrate an embodiment of the invention which will now be described, it being understood that certain modifications in respect of structural details may be made without departing from the spirit of the invention or the scope of the appended claims.

In the drawings:

.FIGURE 1 is a side elevational view of an electric switch mechanism which incorporates my switch control device, and is an associated actuating device;

FIGURE 2 is a side elevational view partly in section; FIGURE 3 is an end elevational view;

' FIGURE 4 is a fragmentary isometric view illustrating a portionof the device shown in FIGURES 2 and 3.

As best illustrated in FIGS. 3 and 4, the selector device indicated generally at numeral comprises a shaft 12, a selecting knob 14, a cam member 16, a cam follower 18 and a detent clip 20. Also shown in the drawings are a switch indicated generally at numeral 30 and its associated switch control device indicated generally at numeral 50. The cooperation of the selector device 10., switch 30 and switch control device 50 will be hereinafter described in detail.

As shown in FIGS. 2-4, the selector device 10 is mounted between the upstanding legs 32a and 32b of a U-shaped housing member 32 of switch 30. The shaft 12 is preferably square in lateral cross section and has an end portion 12a of reduced circular cross section. As shown in FIGS. 3 and 4, shaft 12 penetrates the upwardly extending legs 32a and 32b of the housing member 32 and is rotatably supported in parallel relation to the inner end wall 320 of the housing member 32. Leg 32b has a circular opening, not shown,.to accommodate the reduced end portion 12a of shaft 12; and, after the parts are assembled, the end portion 16a of cam member 16 efiectively prevents withdrawal of said reduced end portion from leg 32b. Leg 32a is provided with a circular opening 32d surrounding the shaft 12 and providing a bearing therefor. A portion 12b of shaft 12 extends outwardly of the housing member 32 and is provided with a selecting knob 14 non-rotatably attached to the outer extreme portion thereof by a set screw or the like.

Cam member 16 is preferably stamped and formed from spring steel or other suitably resilient metal. As best illustrated in FIG. 4, cam member 16 is substantially T-shaped and has a laterally extending end portion 16a bent upwardly at a right angle to an outer body portion 16b, an inner body portion 160 which is parallel to and offset upwardly from the outer body portion 16b, and a rounded toe portion 16d bent upwardly at the inner end of inner body portion 16c. The cam member 16 is alined with the longitudinal axis of shaft 12, as shown in FIG. 4 and is secured thereto by a pair of screws 60-60; and as shown in FIG. 3, toe 16d is centrally located between legs 32a and 32b.

The detent clip 20 comprises a rectangular piece of flexible metal bent to form a substantially V-shaped reentrant member having extending arm portions 20a and 20b and a rounded elbow 20c. Arm portion 20a is provided with a circular aperture 20d near its outer extreme. Arm portion 20b has its outer extreme portion bent outwardly as shown in FIG. 3, to form a tongue 20e. The reduced end portion 12a of shaft 12 extends through aperture 20d to retain arm portion 20a of detent clip 20 between shaft 12 and leg 32b of housing member 32. The rounded elbow 20c tangentially engages end wall 320 of housing member 32 thereby preventing detent clip 20 from rotating with shaft 12. Arm portion 20b is bent upwardly sufficiently to bias it into firm engagement with shaft 12. It will be understood that as the shaft 12 is rotated, the upward bias of arm 20b will tend to detain the shaft 12 in successive stable rotary positions wherein one of the three available flat lateral surfaces of shaft 12 is in parallel abutment with arm 20b. The rotary movement of shaft 12 is limited to one hundred and eighty degrees by the abutment of the lateral extensions 16c of cam member 16 and the end wall 320 of housing member 32 as the selecting knob 14 is rotated. Thus, selector knob 14 is provided with three stable positions at ninety degree intervals by the cooperation of shaft 12 and detent clip 20, and its opposite extreme rotary positions are established by the cooperation of cam member 16 and the end wall 32c. 7

As best illustrated in FIG. 2, the cam follower 18 comprises an inverted U-shaped member having legs 18a and 18b. Thelower end of leg 18a is permanently and rigidly secured by spot welding or the like to a flipper lever 40 which forms a part of an over-center switching mechanism of switch 30. As shown in FIGS. 2 and 3, the cam follower 18 overlies and surrounds the toe portion of cam member 16 with the lower extremes of legs 18a and 18b extending downwardly below shaft 12.

The switch mechanism 30 and the switch control de vice 50 form no part of this invention; however, a more complete understanding of thhe operation of the selector will be had from a brief recitation of the cooperation of the above mentioned devices.

Referring to FIG. 2, the essential elements of switch 30 are the movable contact 34, stationary contact 36, contact actuator bar 38, flipper lever 40, flipper spring 40a, coiled spring 42, spring gland 44, and lever 46. A detailed description of the construction and operation of switch 30 may be had by reference to US. Patent No. 2,781,431. The actuating device 50 is of the vacuum sensing type and is provided with a housing 52 and a pressure operated pushrod 54 extending outwardly therefrom to engage the aforementioned spring gland 44 of switch 30.

The actuating dew'ce 50 is connected to a source of pressure in the vacuum range and is adapted to translate a change in such pressure into vertical displacement of the pushrod 54. As the pushrod 54 moves outwardly of housing 52, it exerts a force upon spring gland 44 suflicient to compress the coiled spring 42. The lever 46 is then free to pivot in a counter-clockwise direction about its base and carries the upper end of flipper spring 40a overcenter. The lower end of flipper lever 40 then moves toward the left-hand side of housing 32, as viewed in FIG. 2, and the contact actuating bar 38 being attached to the lower end of leaf spring 32 is also moved to the left, thereby causing the movable contact 34 to disengage from stationary contact 36.

With the selector knob of our selector device in the position shown in FIG. 1, the toe portion 16d does not engage the cam follower 18 and the flipper lever 40 is free to move in the manner just described; therefore, the

contacts 34 and 36 open and close in response to a change in pressure sensed by actuator device 50.

When the selector knob is rotated counterclockwise through ninety degrees to the off position, as indicated in FIG. 1, the shaft 12 is similarly rotated and the toe portion 16d of the attached cam member 16 engages leg 1% of cam follower 18 to move the latter to a position indicated by a broken line follower held in this position by the coaction of shaft 12 and detent clip 20, the flipper lever 40 is held in an extreme left-hand position thereby causing the contacts 34 and 36 to remain open and non-responsive to the actuating device 50.

Rotation of the selector knob 14 to the on? position shown in FIG. 1, causes the toe 16d to rotate into engagement with leg 18a of cam follower 18 thereby moving the latter together with flipper lever 40 to an extreme right-hand position. In this position the contacts 34 and 36 are held in a closed position by the contact actuator bar 38, and the actuating device 50 is rendered ineffective to open the same. a

Thus, it will be understood from the foregoing that the selecting device is operable to three positions, on, vacuum operated and "o and that switch 30 is thereby adapted for three modes of operation, viz., continuously energized, responsive to a vacuum sensing device 50, and continuously deenergized.

An essential feature of this invention is found in the simplicity of its construction and the low cost of its manufacture. While incorporating sound design principles, inexpensively stamped and formed parts have been employed wherever possible and the total number of parts required has been minimized.

.We claim:

, 1. In combination',a rotatable member having a plurality of flat surfaces extending longitudinally therealong, mounting means adapted to rotatably support end porin FIG. 2. With the cam intermediate the ends thereof, and cam follower means substantially surrounding said camming means in spaced apart relationship thereto, said camming means being adapted to resiliently engage and to displace said cam follower means upon rotation of said member.

2. The combination according to claim 1 wherein said camming means is provided with a pair of integrally formed lugs extending outwardly therefrom, said lugs being cooperable with said -mounting means to limit rotary movement of said member to less than three hundred'and sixty degrees.

3. The combination according to claim 2, wherein said cam follower means comprises a U-shaped member having leg portions resiliently engageable by said camming means, one of said leg portions being permanently attached to a movable switch contactor member, and said camming means being operable upon rotation to one extreme rotary position thereof to engage said one leg portion thereby moving said contactor member in a given direction, and upon rotation to the opposite extreme rotary position thereof, to engage another of said leg portions thereby moving said contactor member in a direction opposite to said given direction.

References Cited in the file of this patent UNITED STATES PATENTS 1,955,091 Raney Apr. 17, 1934 2,061,270 Carlson -'Nov. 17, 1936 2,351,038 Grooms June 13, 1944 2,385,356 'Gilman et al Sept. 25, 1945 2,459,522 Grooms Jan. 18, 1949 2,774,839 Grooms 1. Dec. 18, 1956 2,934,615

Goral Apr. 26, 1960

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