US1810931A - Electric switch - Google Patents

Description

June 23, 1931. H; A SPAHR ELECTRIC ,SWITCH Filed Oct. l0, 1927 2 Sheets-Sheet l June 23, 1931.

H. A. sPl-IR K 1,810,931

' y ELECTRIC SWITCH Filed 001'.. l0, 1927 2 Sheets-Sheet ,2

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Patented June 23, 1931 UNITED ASTATES AHOWARD A.. SIEAHR, OF MILWAUKEE, WISCONSIN ELECTRIC swrr'cn- Applicat'ion filed 0ctober'10, 1927. Serial No. 225,221.

This invention relates to electric switches, and is particularly directed to an electric switch of the push button type, Vpush pull type, or pendant switch type, or others of this general order.

` Objects of this invention are to provide a novel form of electric switch which has a quick make and break, which is formed of a very small number of parts, which may be made in any size or capacity, which 1s extremely compact, and in which the parts are very readily assembled. I

Further objects of this invention are to provide a switch which is so constructed that the rocker bar may be positively dislodged by the push button or manually operable member, for instance, in the event that the rocker bar sticks and is not dislodged by the spring action, and to provide a novel form of switch in which the rocker bar has a quickv motion imparted thereto for either direction of travel of the reciprocatory member. Further objects are to provide an electric switch of the above type in which no mounting frame is required, but in which the parts rest upon the case and in which the stresses are borne by the rocker arm and reciprocatory member and are not transmitted to the case. Y

Further objects are to provide a switch having a plunger and a rocker bar and a s spring in which the spring mounting is such that no additional pins, thimbles, or other spring holding means are required, but inerates directly with the reciprocatory member to provide a pivotal mounting for the spring. Y

Further objects are to provide a 'switch in which a two part casing may be employed to enclose the switch parts themselves in a novel manner permitting the stresses, as stated, to be borne by the rocker arm and plunger themselves instead of by the case,and without the ing in the screws andthe switch `parts inthe event that one-half of the case is removed stead the spring is so formed that it coop# use of any mounting frame, as stated above,A and to provide means for temporarily hold-v Embodiments of the invention are shown in the accompanying drawings in which:

Figure l is a longitudinal sectional view on the line 1-1 of Figure 2; .A

Figure 2 is a'transverse sectional view on the line 2-2 of Figure 1;

Figure 3 is a transverse sectional view on the line 3-3 of Figures 1 and 4;

Figure 4 is a plan view of a part ofthe casing with` the rocker bar and plunger removed;

Figure 5 is a side elevation of a modified form of switch with parts in section;v

Figure 6 is a longitudinall sectional view of a further form of switch.

Referring to the drawings, particularly Figures 1 to 4, it will be seen that the switch comprises an upper .and a lower casing 1 and 2, respectively, which are held together by means of screws 3. These screws have a reduced shank portion 4 which is smaller than l the threaded part 5. i Further, it will be seen that the upper casing 1 is bored out, as indicated at 6, and has a threaded portion 7 whose internal diameter is slightly less 'than the bored out portion 6. This permits the insertion of the screw into the member 1 by screwing it through the threaded portion 7 Thereafter, the screw is held against coin-l plete dislodgment from the member 1, although the member may be turned upside' down. The vreason for this is that the enlarged threaded portion 5 merely contacts with the threaded portion 7 of the casing 1 and prevents the screws from droppingout.

This feature, although apparently only a de- A tail, is nevertheless extremely serviceable Jin connecting up the switch for it is not necessary to carefully vremove the screws to prevent their loss as the screws are automatically held to the upper casing.

Each of the casing members is provided with a out out portion S'which together form a main compartment within which the rocker arm 9 is positioned. This rocker arm is provided with a pair of trunnions 10y which may be formed by slipping rings over-the projecting ears 11 of. the rocker bar, as shown structions could he'used. These trunnions in Figure 3, although obviously other con- Y are received within slots or cutouts 12 formed in the lower casing member 2 and, if desired, a small piece of fibre or libre paper 13 may be slipped linto place above the trunnions to prevent dislodgment of the rocker bar even if the switch is opened and the bottom casing inverted. 'This construction is shown most clearly in Figures 1 and 2.`

It is to-be noted further that the upper. casing member 1 is provided with a pair of downwardly extending lugs 14 which are positioned within the cutouts 12.

The lower casing member 2, as shown in Figure 4, is provided with two pair of stops l5 which are positioned on opposite sides of the central cutout 8. These stops arrest the motion `or limit the extreme motion ofthe rocking bar 9. Further, as shown in Figure 4, a pair of stationarycontact ngers 16 may be. provided which, if desired, are made of relatively springy brass or bronze, or other suitable material. Between these spring fingers the upper end of the rocking bar 9 is adapted to be positioned when the switch is closed. It is to be noted also that the stops 15 are positioned inside of the contact 16 and consequently in connecting up the switch, no

v displacement of the contacts can occureven though the operators screw driver should strike one of the contacts. This is secured as stated because of the positioning of the stops 15 which act as limiting stops for the stationary contacts also.l In addition-to this, the stops 15 on the side of the casing from the contacts provide guides for thethrough .wire andthus prevent the wire from becomingwlsntangled with the mechanism.

e lower casing member 2 is provided with a pair of transversely positioned'and aligned cutouts 17, similar cutout portions 18 being provided in the'upper "casin member. These cutout portions receive the insulating handles 19 of the oscillatory or reciprocatory member which operates the rocking bar. The handles .are connected by means -of a metal body portion 2() and together with this metal body portion form the oscillatory part of the switchf This metal body portionas downwardly projecting lugs 21 which are received within slots 22 formed in the lower casing mem-ber,`as shown most clearly in Figures 2 and 4c.

It is Ato be noted particularly'that the central portion of the rocker bar 9 is cut out and atits upper portion it is provided .with a downwardly extending lug 23 which receives the upper end of the compression spring 24. The lower end of the compressionsprin'g has its last convolution stopped half-way and has the last strand 25 bent diametrically across the spring, as shown in Figure 2. This providesa centrally locatedbearing support for the spring which is formed integrally with ceived. This reciprocatory member therefore i is held against lateral rocking motion with respect to the rocking bar and also holds the rocking bar itself against lateral motion. Ing

addition to this, it may be found desirable to form the handles 19 (see Figure 2) rectangular, and to correspondingly shape the notches or cutouts 17 and 18. l

The operation of the switch is as follows:

.Assume thatthe switch is open, as shown in Figure 2, and that the operator presses the button or handle 19 inwardly. This causes the bottom pivot point of the spring to travel to the right in Figure 2, and in addition Ato this, one vof the projecting tongues 21 engages the downwardly extending portion 9 of the rocking bar below the line ofthe trunnions. This starts thel rocking bar and the switch completes the rocking motion in the left hand direction or counter clockwisedirection, as viewed in Figure 2. Thus, the switch has a quick make. `A reverse motion of the reciprocatory vmember will cause the other downwardly projecting member 21 to engage the lower end or portion 9 of the rocking bar, and a similar action will take place, the rocking bar then travelling in a clockwise direction back into the position shown in Figure 2. This gives a quick break.

of the rocker bar, and in which the downwardly projecting lugs 21 of the reciprocatory member merely come into engagement withX the downwardly projecting portion of the rocker bar when the rocker bar tends to stick.

It is to be noted that the downwardly extending member 9 also acts as a stop for the reciprocatory -member as it strikes against one or the other of the lugs 21 at the limit of motion ofthe switch. i l

It-nay be desirable to assemble the parts one from the bottom of the portion ofl the casing and the otherfrom the top. For instance, as shown in Figure 5, Ythe lower member 28 of the casing is similarly formed to the member 2 of the casing, previously described, except that the trunnion receiving notches or slots 29 open through its bottom edge and also a slot is provided in the bottom .edge communicating with these slots 29. The rocking bar 30 is substantiallysimilar to the rocking barjpreviously described, except that it has a slot 31 through its upper side which extends downwardly between the projecting spring receivinglugs 32. This permits the positioning of t e reciprocatory member 33.

The slot in the bottom portion of the casing 28 is closed in any su1table manner as by followed as in Figure l, for instance, such member being indicated by the reference character 35. Also, a similar type of rocking bar 36 may be provided for engagingr the stationary contacts 37. Y The spring 38 1s mounted in the same way, as previously described. However, the casing members 39 are formed to provide an opening only at one end which receives the fitting 40. This fitting is threaded, as indicated at 41, and is adapted to be passed through a panel and secured by suitable nuts in a well-known manner. The

reciprocation member 35 has an extension 42 guided in one end of the casing and at its other end is connected by means of an insulating strip 43 with the operating handle or stem 44. The stem and insulating strip 43 are guided in the fitting and consequently correctly support the outer end of the reciprocatory member 35. y

This form'of switch can be used as a push pull switch, if desired. In addition to this, it is clear that other forms of switches may be employed which embody the invention disclosed in this case. For instance, the reciprocatory member could be urged in one direction by a spring so that it could be used as an instantaneous switch by merely pressing merely blanked out downwardly or inwardly upon the projecting handle. Obviously, the casing could be changed so that the switch could be a pendant switch without departing from the spirit of this invention. Y

It is apparent that all of the forces due to the action of the spring may be borne internally, that is to say, may be borne by the reciprocatory member and the rocking bar and the forces of the spring are not then transmitted to the supporting casing. In addition to this, it is also clear that no mounting frame need be used with this switch, thus very markedly simplifying its construction.

It is to be noted also that a novel form of switch has been provided in which no forming operations whatsoever are needed for the mechanism itself, that is to say, for the movable parts. Instead, these movable parts are of sheet material. Obviously, eliminating the forming operations materially reduces thecost of the switch.

It has been found that the frictional loss and consequently the effort required to operate the switch is reduced to a minimum, although a stiff spring may be used. This, therefore, greatly increases the ease of operaaperture, said second tion of the switch.- Further, it is apparent from the description and the drawings that the switch has a very small number of easily produced parts and that these parts may be assembled with the utmost ease.

Although the invention has been described in considerable detail, such description is intended as illustrative rather than limiting as the invention may be variously embodied and as the scope of such invention is to be determined as claimed.

I claim: y

1. An electric switch comprising a twopart casing, one of said parts having a threaded aperture, screws carried by the other of said parts and extending into said threaded entioned part of the casing having a t aded portion through which the threaded portion of the screw may be passed, said screw having a shank of reduced diameter from the external diameter of the threadedpart, whereby the screw is prevented from inadvertently dropping from the `second mentioned portion. thereof, and switch mechanism carried Within said casing.

2. -An electric switch comprising a pivoted rocking bar, stationary contacts adapted to be engaged by said rocking bar, a reciprocatory member for actuating said rocking bar, said rocking bar having a downwardly extending portion, lugs extending downwardly from said reciprocatory member and adapted to engage said downwardly extending portion of said rocking bar during the completion of the stroke of` the reciprocatory member in the event that said rocking bar sticks,

.said downwardly extending portion of said rocking bar also constituting a stop for said lugs to limit the stroke of said reciprocatory member, and a compression spring between said rocking bar and said reciprocatory member.

3. An electric switch comprising a base, a pivoted rocking bar carried by said base, lstationary contacts adapted to be engaged by said rocking bar, a reciprocatory member for actuating said rocking bar, va compression spring interposed between said reciprocatory member and saidrocking bar, said spring holding said rocking bar and said reciprocatory member to said base, said rocking bar having an opening and said reciprocatory member having a portion passing through said opening, and means carried by-said reciprocatory member and adapted to engage said rocking-bar during the completion of ros the stroke of said reciprocatory member in and said reciprocatory member, said reciprocatory member having downwardly extending lugs and said rocking bar having a downwardly extending portion adapted to be engaged by said lugs during the completion'of the stroke of the reciproeatory member in the event of sticking of the rocking member, said rocking bar having a sl with said opening, whereby said reciprocatory member may be passed through said slot during assembly.

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in the county of Milwaukee and State of Visconsin.

HOWARD A. SPAHR.

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