US1974053A - Switch mechanism - Google Patents

Description

Sept. 18, 1934. R PQPP 1,974,053

SWITCH MECHANISM Filed May 12, 1931 Fig.

Patented Sept. 18, 1934 UNITED. STATES 1,974,053 SWITCH MECHANISM Rudolf Popp. Valparaiso, Ind., assignor to McGill Manufacturing Company, Valparaiso, Ind., a

corporation of Indiana Application May 12, 1931, Serial No. 536,824

5 Claims.

My invention relates to a switch mechanism and more particularly to the type of switch mechanism in which a reciprocating motion is converted to rotary movement of a bridging contact.

Heretofore it has been customary to provide a rotatable bridging contact unit consisting of a number of parts which were constructed and arranged to cooperate with one another to provide a definite spacing and effect a certain operation of the device. A switch mechanism of this type is described in my copending application Serial No. 512,836 filed Feb. 2, 1931.

In accordance with the general features of the present invention I provide an integral bridging contact unit which eliminates many of the parts of the former construction while retaining all of the corresponding functions and advantages and having at the same time additional advantages.

An object of the invention is to provide a new and improved switch mechanism.

A further object is to provide a switch mechanism having no lost motion between the elements of the bridging contact unit.

A further object is to decrease the number of exposed metallic parts which might result in a short circuit.

A further object is to provide a switch mechanism which may be readily and economically assembled.

other objects and advantages will appear as the description proceeds.

Referring to the drawing:

Fig. 1 is a plan view partially in section taken on lines 11 of Fig. 2.

Fig. 2 is aside elevation partly in section taken on lines 2-2 of Fig. 1;

Fig. 3 is an end view of the device shown in Fig. 4 is a perspective detail view oi a pawl used in the device;

Fig. 5 is a perspective view or the bridging contact unit, and

Fig. 6 is a bottom view or the device shown in Fig. 5.

Referring now more in detail to the drawing, the switch mechanism is mounted between a pair of insulating plates 12 and 13 of any suitable insulating material which are spaced apart and held in position by a pair of posts 14 and 15 which extend through the platesand are upset at their upper and lower ends to clamp the plates and hold them in position.

A is shaped member 2% is supported between plates 12 and i3 and has projections adapted to extend into these plates to hold the member in position. This member has a round collar as attached to its end upon which a lever 31 is adapted to rock when a tension is applied to chain 32. Lever 31 is connected to a stem 33 by a universal connection whereby the rocking of lever 31 in any direction will pull the stem to the right as viewed in Figs. 1 and 2. Stem 33 is provided with a head 46 and carries a U-shaped pawl 43 having arms 44 and 45. Surrounding stem 33 is a helical spring 47 which rests at one end against the U shaped member 2'7 while its other end rests against pawl 43, holding the pawl and stem in extended position as shown in Figs. 1 and 2.

Rotatably mounted between the plates 12 and 13 is a unitary contact bridging member 51 having trunnion or stub shafts 52 engaging apertures in plates 12 and 13. The general configuration of the contact bridging member is frustum shaped with terraced sides, having a large toothed wheel 53 provided with alternately deep and shallow teeth. The shallow teeth are provided with conducting faces 54 all of which are interconnected by a spider 55. Adjacent the wheel 53 and integral therewith is a ratchet Wheel 56 having teeth of a number corresponding to the teeth of the larger wheel 53. Adjacent the ratchet wheel 56 and integral therewith is a cylindrical disc or collar 5'7. When the device is assembled the arms 44 and 45 lie against the periphery of disc 5'7 and straddle this disc, and arm 45 is provided with a. lateral projection 58 which engages behind the teeth of ratchet wheel 56. The arms 44 and 45 are of slightly smaller width than the height of disc 57 so that they may move freely in the space between the ratchet wheel and plate 13. The object in providing the two arms 44 and 45 is to aid in the positioning of the pawl and at the same time provide a tension on these arms toward the disc 57. Due to the fact that the contact bridging wheel 53, ratchet wheel 56 and disc 5'? are made integral, there is no lost motion between these parts and the stud shafts 52 integral with the bridging unit, prevent the danger of short circuit which is present when these members are made of metal, particularly in the case of the lower stud shaft which passes through an aperture in spider 55. The entire bridging contact member may be cast in a mold of bakelite, hard rubber or any other suitable materials.

Each of the posts 14 and 15 carries a stationary contact member 37 of resilient material. These contact members are so bent as to have inwardly curved contacting portions lying substantially opposite each other for engaging the movable contact bridging member and has a substantially straight portion which is rebent upon itself to give additional resiliency, and at the end of the rebent portions the members are bent at a right angle. These right angle portions are secured in slots provided in posts 14 and. 15. When the stationary contact members 37 pass from the deep cut insulated teeth of the contact bridging member to the shallow contact carrying teeth, the drop is small and the tension of the springs is only slightly released, thus preventing rebound of the stationary contact members when they strike the contact carrying teeth. In one position of the movable contact member both of the stationary contact members will rest upon insulating teeth and in another position of the movable contact member, both of the stationary contact members will rest upon, and be bridged, by teeth having a conducting face in which position posts 14 and 15 will be electrically interconnected. Each of the posts 14 and 15 carries a screw 39 by means of which a conductor may be connected to the posts for placing the switch in an electrical circuit.

It is evident that on account of the unitary construction of the contact bridging member and ratchet wheel, the device may be readily assembled. It has been found that with this construetion the unit may be dipped in a lubricating medium prior to assembly so that all of the parts including the bearings in the plates 12 and 13 will be thoroughly lubricated when the device is assembled.

This practice is not possible where the contact bridging unit is made of a number of parts because when the separate parts are lubricated it makes it extremely difficult to assemble the parts.

The elimination of lost motion between the ratchet wheel and contact bridging wheel is an important feature in a switch mechanism of this type, due to the fact that the movement of pawl 43 is quite limited when a rocking lever such as 31, having a universal connection is used to actuate the pawl.

What I claim as new and desire to protect by Letters Patent of United States is:--

1. In a switch mechanism a pair of bearing members, an integral insulating wheel rotatably secured in said bearing members, said wheel comprising a plurality of integral portions including a peripheral toothed contact bridging portion having metallic conducting surfaces on alternate teeth, with bridging connection between opposite conducting surfaces, a ratchet portion adjacent said toothed contact portion, a collar portion adjacent said ratchet portion, and trunnion shafts on opposite sides of the insulating wheel for fitting in the bearing members, a U- shaped pawl having one leg bearing against said collar and the other leg adapted to engage the ratchet portion, and means for reciprocating the pawl to cause rotation of the insulating wheel.

2. In a switch mechanism, a pair of bearing members, a rotatable member mounted therein comprising an insulating body having trunnions on opposite sides thereof journalled in said hearing members, said insulating body including an integral ratchet wheel, and an integral collar por-' tion adjacent thereto, a pawl having a pair of arms straddling said body with one arm bearing against the collar portion, and a lateral projection on the other of said arms adapted to progressively engage teeth of the ratchet wheel, bridged conductors on said insulating body, and means for reciprocating said pawl to rotate said insulating body, whereby said conductors cooperate to complete a circuit through the switch.

3. In a switch mechanism, a frame comprising a pair of bearing members, posts for securing members in spaced relationship, an integral insulating wheel rotatably secured in said bearing members with a portion of said wheel being formed as a peripheral toothed contact wheel having metallic conducting surfaces on alternate teeth with bridging connection between opposite conducting surfaces, another portion being formed as a ratchet wheel, and a third portion being formed as a guiding collar, oppositely disposed, stationary contact members secured to said posts for peripherally engaging the toothed contact wheel, a pawl normally resting on said guiding collar and having a projection for engaging the ratchet wheel, and means for reciprocating said pawl to move said insulating wheel through said stationary contact members.

4. In a switch mechanism, a pair of bearing members, an integral insulating wheel comprising a plurality of integral portions including a peripheral toothed contact portion having metallic conducting surfaces on alternate teeth with a bridging connection between said conducting surfaces, a ratchet portion adjacent said toothed contact portion, and integral trunnions on opposite sides of said insulating wheel for rotatably mounting the wheel in said bearing members, oppositely disposed yieldable contact members for peripherally engaging said opposite conducting surfaces, and a pawl peripherally engaging said ratchet portion and disposed on one side of the axis of the integral insulating wheel to move the same, said pawl having a balancing guiding portion engaging the integral wheel on the opposite side of the axis thereof.

5. In a switch mechanism, a pair of bearing members, a wheel formed of insulating material journalled in said bearing members and comprising a toothed portion having surface contact members on alternate teeth connected together electrically, and a ratchet portion adjacent said toothed portion and a substantially U-shaped member having two legs of spring material bearing on opposite sides of the wheel, one of said legs having a pawl portion engaging the teeth of said ratchet to turn the wheel one tooth position at each reciprocation of said U-shaped member and the opposite leg engaging said wheel peripherally as a guide and to balance the first mentioned leg to hold it in engagement with said ratchet portion.

RLF POPP.

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