US3219777A

US3219777A - Governor switch having a link with contacts and a lever with contacts both pivotally mounted on the same axis

Info

Publication number: US3219777A
Application number: US96770A
Authority: US
Inventors: Pickles Joseph
Original assignee: Ferro Manufacturing Corp
Current assignee: Ferro Manufacturing Corp
Priority date: 1961-03-20
Filing date: 1961-03-20
Publication date: 1965-11-23
Anticipated expiration: 1982-11-23

Description

J. PICKLES 3,219,777 GOVERNOR SWITCH HAVING A LINK WITH CONTACTS Nov. 23, 1965 AND A LEVER WITH CONTACTS BOTH PIVOTALLY MOUNTED ON THE SAME AXIS 3 Sheets-Sheet 1 Filed March 20. 1961 INVENTOR. (/OfifP/I P/c/a 5 1955 J. PICKLES 3,219,777

GOVERNOR SWITCH HAVING A LINK WITH CONTACTS AND A LEVER WITH CONTACTS BOTH PIVOTALLY MOUNTED ON THE SAME AXIS Filed March 20. 1961 3 Sheets-Sheet Z lllll l ll lllllllblmml I INVENTOR. (/Ojt'P/r p/c/l g 5 Nov. 23, 1965 J. PICKLES 3,219,777

GOVERNOR SWITCH HAVING A LINK WITH CONTACTS AND A LEVER WITH CONTACTS BOTH PIVOTALLY MOUNTED ON THE SAME AXIS Filed March 20. 1961 3 Sheets-Sheet 3 IN VEN TOR. d055 fi/mz 5.

United States Patent GOVERNOR SWITCH HAVING A LINK WITH CON- TACTS AND A LEVER WITH CONTACTS BOTH PIVOTALLY MOUNTED ON THE SAME AXIS Joseph Pickles, Dearborn, Mich., assignor to Ferro Manufacturing Corporation, a corporation of Michigan Filed Mar. 20, 1961, Ser. No. 96,770 Claims. (Cl. 200--80) The invention relates to speed control systems and refers more specifically to a speed responsive switch in a governor for an automobile or similar device which gov- 'ernor in conjunction with the centrifugal switch is operable to indicate that the device is operating at or above a predetermined speed or to bring the device up to a predetermined speed and to hold the device between limits at the predetermined speed and includes override mechanism to permit exceeding of the predetermined speed.

In the past speed responsive switches for use in conjunction with governors have often lacked desired versatility. In particular prior automobile governors including speed responsive switches have often lacked means for bringing an automobile up to a predetermined governed speed and override means whereby at the option of an operator the speed of the automobile could be increased beyond the predetermined speed. Also such governors have often not included means for selectively initiating operation of the governor.

In addition wherein speed responsive switches having required versatility have in the past been provided in governors the switches and resulting governors have usually been complicated whereby their reliability is poor and their expense prohibits their use by the general public.

Therefore, it is one of the purposes of the present invention to provide an improved speed responsive switch for use in conjunction with an automobile governor or the like.

Another object is to provide a speed responsive switch including a first pivotally mounted lever having electric contacts on one end thereof, centrifugal speed responsive means acting on the other end of the lever, spring means operating on the one end of the lever in opposition to the centrifugal means and a second lever pivotally mounted on the same pivot axis as the first lever having electrical contacts thereon positioned on opposite sides of the contacts on the one end of the first lever.

Another object is to provide switch structure as set forth above and further including means for preloading the spring whereby movement of the first lever will not take place until a predetermined speed is sensed by the centrifugal speed responsive means.

Another object is to provide a lost motion pivot connection for the second lever and means for resiliently biasing the second lever in one direction in the lost motion connection.

Another object is to provide structure as set forth above and further including means for determining the position of the second lever relative to the first lever.

Another object is to provide a speed responsive switch as set forth above which is simple in construction, economical to manufacture and efficient in use.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating a preferred embodiment of the invention, wherein:

FIGURE 1 is a partially diagrammatic, partially schematic representation of governing apparatus including speed responsive switch structure constructed in accordance with the invention.

Patented Nov. 23, 1965 FIGURE 2 is a section of the speed responsive switch or mechanical speed sense portion of the governing apparatus illustrated, in FIGURE 1 showing the speed sense elements in the position thereof before governing action occurs in full lines and indicating their position at governing speed in broken lines.

FIGURE 3 is a cross sectional view of the speed sense illustrated in FIGURE 2 taken substantially on the line 33 of FIGURE 2.

FIGURE 4 is a section view of the speed sense illustrated in FIGURE 2 taken substantially on the line 4-4 in FIGURE 3 showing the speed sense elements in the position thereof at governing speed in full lines and indicating their position before governing action occurs in broken lines.

FIGURE 5 is a cross section of the mechanical speed sense illustrated in FIGURE 2 taken substantially on the line 5-5 in FIGURE 2.

FIGURE 6 is an enlarged partial section of the mechanical speed sense portion of the governing apparatus illustrated in FIGURE 1 taken substantially on the line 66 in FIGURE 3.

FIGURE 7 is a schematic diagram of the electric control circuit of the governing apparatus illustrated in FIGURE 1.

With particular reference to the figures one embodiment of the present invention will now be disclosed.

As shown in FIGURE 1 the speed control system comprises the vacuum throttle operating means 10 for positioning a throttle valve 12. The vacuum throttle operating means 10 is actuated by the electric control circuit 14 shown best in FIGURE 6. Portions of the electric control circuit 14 are energized by the speed responsive or mechanical speed sense 16 of the invention shown best in FIGURES 2-6.

The speed control system operates to open the throttle valve 12 to bring the automobile engine or other device with which the throttle valve 12 is associated up to a governing speed and to maintain the speed of the device between predetermined governing limits. In addition override mechanism 18 is provided so that should the operator of the automobile desire he may at any time override the governing apparatus and increase the speed of the automobile beyond the governing limits.

More specifically the vacuum throttle control mechanism 10 comprises the solenoid armature 20 slidable within the cylinder 22 and secured to one end of the armature rod 24. The armature rod 24 is connected to throttle actuating linkage 26 through the override mechanism 18.

The throttle actuating linkage 26 includes the actuating rod 30, lever 32 and member 33 for pivoting the throttle into an open position on movement of the actuating rod 30 to the right in FIGURE 1. Actuating rod 30 may be moved to the right by moving the accelerator pedal 34 in a counterclockwise direction about pivot means 36.

Override mechanism 18 comprises an abutment 38 on the end 40 of the armature rod 24, and a further abutment 42 on the armature rod 24 spaced from the end 40 thereof. A flange 44 on the end 46 of the actuating rod 30 is provided with an opening 48 therein, and is sleeved over the end 40 of the armature rod 24 for reciprocation between the abutments 42 and 38. The override mechanism is completed by the prestressed spring 50 acting between the abutment 38 and the flange 44 to urge the flange 44 into contact with the abutment 42.

Thus in operation when it is desired to override the governor mechanism and to move the actuating rod 30 to the right a distance greater than allowed by the positioning of the armature rod 24 by the vacuum throttle operating means, sufficient pressure is placed on the accelerator pedal to overcome the prestressing of the spring whereby the flange 44 is moved toward the abutment 38 of the armature rod 24 and the throttle valve 12 is opened.

Armature rod 24 reciprocates within the core 52 of the solenoid 54 secured within the reduced diameter portion 56 of the cylinder 22. The armature rod 24 is insulated from the solenoid 54 by the insulating sleeve 58 as shown. The solenoid 54 is energized through conductor 60, the flexibily mounted contact 61, armature 20, and armature rod 24 to ground on movement of the armature rod to the right in FIGURE 1 by means of the accalerator pedal 34 and actuating rod 30. After the initial completing of the circuit through the solenoid 54 by means of the accelerator pedal the armature is held in contact with the solenoid 54 by magnetic attraction to maintain electric engagement between armature 20 and contact 61 and thereby keep the solenoid 54 energized.

Cylinder 22 has diaphragm 62 secured to the end 64 by convenient means, such as plate 66 and rivets 68. The outer periphery of diaphragm 62 is secured between the housing members 70 and 72 as shown. Housing members 70 is provided with an opening 74 therethrough in which the collar 76 is rigidly mounted to provide a guide for sliding axial movement of the cylinder 22. The housing part 70 is also provided with an opening 82 therethrough for maintaining the pressure between housing part 70 and diaphragm 62 at that of the surrounding atmosphere.

The cylinder 22 further includes an abutment 78 secured to the other end thereof. Spring 80 having one end abutting against the abutment 78 and the other end abutting against the collar 76 is provided to bias the cylinder 22 which is connected to the diaphragm 62 and guided in the collar 76 to the right, as shown in FIGURE 1.

A pair of solenoid actuated valves 84 and 86 are secured to the housing portion 72. The valve 86 is provided to connect the chamber 88 formed between the diaphragm 62 and housing member 72 to a source of vacuum 90 when energized. The valve 84 is operable only when energized to connect the chamber 88 with the surrounding atmosphere.

Solenoids

85 and 87 of valves 84 and 86 respectively are connected in the electric control circuit 14 so that both may not be energized at the same time.

Valves 84 and 86 are entirely similar and therefore only valve 86 will be considered in detail. The valve 86 includes an actuating solenoid 87 and the shaft 94 extending axially through and guided by the solenoid core 26. Spring 98 is provided to bias the shaft 94 and the disc 100 carried thereon toward the housing member 72. The valve head 102 is mounted on disc 100 for seating against the housing portion 72 over the metering orifice 104 therein.

Thus on coil 87 being energized the shaft 94 and disc 100 will move to the left as shown in FIGURE 1 whereby the valve head 102 will unseat to permit a vacuum to be drawn in chamber 88 by vacuum source 90. The valve 84 which is similar to the valve 86 is un-energized at this time so that the valve head 106 thereof has sealed the metering orifice 108.

Conversely if the solenoid valve 84 is energized the chamber 88 is open to the atmosphere and valve head 102 is seated against the housing member 72. When both valves are closed thet chamber 88 is constructed to maintain the vacuum condition therein at the time of seating of the valve heads 102 and 106.

Thus in operation the position of the armature rod 24 is determined by the vacuum condition in the chamber 88 when the solenoid 54 has been energized since the vac uum condition in chamber 88 determines the position of the cylinder 22 which moves in opposition to the spring 80 on a vacuum being drawn in the chamber 88.

The mechanical speed sense 16 includes the housing 110 having the base 112 and cap 114 which may be secured together by convenient means (not shown). A rotatable shaft 116 extends through the housing 110 and is supported in

bushings

129 and 130 for rotation due to engagement with the squared ends of drive cables and 117. Drive cables 115 and 117 are rotatably supported in

bearings

118 and 120 in the sleeves formed by the

annular flanges

122 and 124 respectively on the base 112 and cap 114 as shown. Bearing 126 carrying disc 127 is secured to bushing 1'50 mounted on shaft 116 as shown. A ball separator 132 having radially extending slots 134 therein in which the ball weights 136 move on rotation of shaft 116 is secured to shaft 116 for rotation therewith as shown best in FIGURES 2 and 5. The annular ball retaining cup 138 is sleeved over shaft 116 and retains the ball weights 136 within the radial slots 134.

In operation the shaft 116 is rotated at a speed proportional to the speed to be governed. For example, in an automobile the shaft 116 may be connected to rotate at the speed of the speedometer cable through cable 115 or cable 117 or if it is desired to govern engine speed cable 115 or 117 may be rotated by the engine. On rotation of the shaft 116 the balls 1336 move radially outwardly in the slots 134 due to centrifugal force and force the cup 138 which is slidably mounted on the shaft 116 to move to the left, as shown in FIGURE 2, against the bias applied thereto by means of the spring 140 through lever 142. Thus the position of the lever 142 is a direct function of the speed of rotation of the shaft 116 and the resisting force applied thereto by the spring 140.

Lever 142, shown best in FIGURES 2, 3 and 4, is pivotally mounted on pivot pin 144. Lever 142 is provided with flanges 145 for stiffening and pivotal mounting thereof. Lever 142 has notch 146 in the end 148 thereof through which the shaft 116 extends. The flanges 145 are further provided with the rounded end portion 150 urged into engagement with the cup 138 by the spring 140. End 152 of lever 142 is provided with

electric contacts

154 and 155 on opposite sides thereof.

A contact member 156 as shown best in FIGURES 3 and 4 is sleeved on the fiat portion 158 of the pivot pin 144 and is secured to the pivot pin 144 for rotation therewith by means of the lost motion connection therebetween as shown in FIGURE 6. The contact member 156 is generally U-shaped, as shown best in FIGURE 4, and has the

leg portions

162 and 164 rigidly secured together by means of the hub 166 having opening 167 shaped as shown therein through which the pivot pin 144 extends.

Electrical contacts

168 and 170 are secured to the outer ends of the

legs

162 and 164 of contact member 156 on opposite sides of the end 152 of lever 142. On pivoting of the lever 142 about the pivot pin 144 in a counterclockwise direction, as shown in FIGURE 4, the contact member 168 will engage the contact member 154 on one side of the lever 142 whereby an electrical circuit will be completed through the contact members. On pivoting of the lever 142 in a clockwise direction about the pivot pin 144 an electric circuit will similarly be completed through the

contact members

170 and 155.

Spring which is fixed to the pivot pin 144 at one end and to the contact member 156 at the other end is provided to urge the contact member into the position relative to the pin 144 shown in FIGURE 6. Substantial angular movement between the contact member and pin 144 due to clockwise movement of lever 142 is permitted by spring 160 on application of little force to lever 142 above that necessary to overcome the force of spring 140 since spring 160 is relatively weak. The lost motion connection illustrated in FIGURE 6 and spring 160 thus cooperates to prevent any substantial pressure from being applied to accelerator pedal 34 by lever 142 during operation of the governor which might otherwise occur as will become more evident when the over-all operation of the governor is considered.

The link 172 is rigidly secured at end 174 to the outer end 176 of pivot pin 144 as shown best in FIGURE 3. The link 172 is connected at the other end 178 to the armature rod 24, as shown diagrammatically in FIGURE 1, to provide a feed back from the vacuum throttle operating means in operation. The link 172 is so connected to the armature rod 24 that closing the throttle 12 produces clockwise movement of the link 172, as shown in FIGURE 4, and movement of contact 168 toward engagement with the contact 154. Similarly opening of the throttle 12 causes counterclockwise movement of the link 172 in FIGURE 4 by the rod 24, so that the contact 170 is moved toward engagement with contact 155.

As previously indicated the spring 148 is provided to bias the lever 142 into engagement with the cup 138 of the speed sense at all times. The end 180 of spring 140 thus bears against the end 152 of the lever 142 while the end 182 of the spring 140 bears against the adjustable abutment 184. Spring 140 is under initial compression so that the lever 142 will not begin to pivot about the pivot pin 144 until a speed closely approaching the governing speed is reached. At the governing speed the force applied to lever 142 by the spring 140 will exactly balance the force applied to the lever 142 by the cup 138 due to radially outward movement of the balls 136 on rotation of the shaft 116. The speed at which such balance will occur may be adjusted by moving the position of the abutment 184 by means of cable 185.

The electric control circuit 14 of the speed control system of the invention, best shown in FIGURE 7, will be considered in conjunction with the over-all operation of the speed control system. In over-all operation it will be assumed that the speed control system is installed in a vehicle having a battery 186 and that the vehicle is in operation at a speed below the desired governing speed with the ignition switch 188 closed.

When the vehicle operator desires to operate the vehicle at governed speed a manual switch 190 which may be conveniently located for operation by the vehicle operator is actuated to complete an electric circuit from the battery 186 through a switch holding solenoid 192. The accelerator pedal 34 of the vehicle is then pivoted counterclockwise to open the throttle 12 and move the actuating rod 26 and armature rod 24 to the right in FIGURE 1 to cause engagement between armature and flexible contact 61 of solenoid 54. The solenoid 54 is thus energized by the battery 186 through the normally closed brake switch 194, solenoid 54, armature 20 and armature rod 24. The armature 20 is therefore held in contact with the solenoid 54 for movement with the cylinder 22 as previously indicated.

At this time the cylinder 22 is biased in a limiting position to the right in FIGURE 1 by the spring 80 so that the rod 24 holds the throttle 12 in an open position. Also the feed-back link 172 at this time is in a limiting counterclockwise position in FIGURE 4 whereby the contact member 156 is also in a limiting counterclockwise position, as illustrated in dotted lines at 196 in FIGURE 4.

The lever 142 is in a limiting counterclockwise position since the vehicle has been travelling at a speed below the governing speed thereof and the spring 140 is under compression so that it will not begin to move in a clockwise direction about the pivot pin 144 until the speed of the automobile approaches the governing speed. If, for instance, the governing speed of the vehicle is set at sixty miles per hour, the compression of the spring 140 may be set so that the lever 142 does not begin to move in a clockwise direction until the speed of the vehicle is fifty-nine miles per hour.

Thus until the speed of the vehicle is raised by the open throttle to fifty-nine miles per

hour contacts

168 and 154 are engaged to energize the solenoid actuated valve 84, as shown in FIGURE 1, whereby the chamber 88 is opened to atmospheric pressure. At fifty-nine miles per hour the notation of the shaft 116 produces movement of the cup 138 to pivot the lever 142 in a clockwise direction in opposition to the bias of the spring 140 so that the engagement between the

contacts

154 and 168 is broken so that valve 106 closes opening 108. The clockwise movement of the lever 142 will continue as the speed of the vehicle increases to sixty miles per hour at which time the

contacts

155 and 170 engage to energize the solenoid actuated valve 86 whereby a vacuum is produced in the chamber 88 by vacuum source 90.

The vacuum in chamber 88 will cause the cylinder 22 to move in a left direction in FIGURE 1, to produce closing of the throttle 12 through the armature rod 24. Movement of the armature rod 24 in a leftward direction produces clockwise movement of the feed-back link 172 to produce clockwise movement of the contact member 156 and therefore disengagement of the

contact members

155 and 170. Since both solenoid actuated valves 84 and 86 are unactuated at this time the vacuum condition in the chamber 88 will be maintained. The vehicle speed at this time will be between fifty-nine and sixty-one miles per hour or approximately sixty miles per hour at which speed the lever 142 is balanced by spring and weights 136 through cup 138 with the

contacts

154, 168, and all out of engagement.

Should the vehicle speed again increase beyond the governing speed the lever 142 will again move to engage the contacts 155 and 17 0 to draw vacuum in the chamber 88 and more fully close the throttle 12 in the manner previously indicated. Should the speed of the automobile decrease the lever 142 will move in a counterclockwise direction to engage the

contacts

154 and 168 whereby the chamber 88 is open to the atmosphere through port 109 and the cylinder 22 is moved to the right in FIGURE 1 by the spring 80 to open the throttle.

Thus it will be seen that the speed of a vehicle having the speed control system including the speed responsive switch of the invention installed therein may be brought to governing speed and maintained between very close limits, for example, between fifty-nine and sixty-one miles per hour if the governing speed is sixty miles per hour automatically after the initial actuation of the governor switch and the initial opening of the throttle valve.

Further it will now be evident that during an increase in speed when the lever 142 is moved in a clockwise direction the lost motion connection between the pivot pin 144 and contact member 156 prevents link 172 from applying force to accelerator pedal 32 other than that transmitted by the relatively weak spring 160.

Should the operator desire at any time, such as during passing of another automobile, to exceed the governed speed, it is only necessary to depress the accelerator by a. force sufiicient to overcome the compression of the spring 50 of the override mechanism previously considered to open the throttle as wide as desired.

Also, it will be noted that if it is desired to slow down the brake switch 194 operates to de-energize the solenoid 54 whereby normal operation of the vehicle may be continued until the accelerator pedal is again actuated to complete the circuit through the solenoid 54.

The drawings and the foregoing specification constitute a description of the improved speed control system in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. A speed responsive switch comprising a housing, a pivot pin extending transversely of said housing, a movable link rigidly secure'd to said pivot pin externally of said housing, a contact member mounted on said pivot pin within said housing for limited rotation with respect thereto, a pair of spaced apart electric contacts secured to said contact member, resilient means secured to the pivot pin and engaged with the contact member for biasing the contact member into a predetermined position relative to the pivot pin, a lever mounted on said pivot pin within said housing for rotation relative thereto having a pair of contact members secured thereto alternatively engageable with a corresponding one of the electric contact-s on the contact member on relative movement between the lever and contact member in opposite direc-- tions, a centrifugal speed responsive weight assembly positioned within said housing engageable with one end of said lever for producing relative movement between said lever and contact member and pre-loaded resilient meansv enageable with the other end of the lever for deterrnim ing at what speed movement of the lever relative to the contact member will be initiated by the centrifugal speed responsive means.

2. A speed responsive switch comprising a movable: link, a contact member, a lost motion connection between the link and contact member for securing the contact member to the link for movement therewith, a pair of spaced apart electric contacts secured to the contact mem-- her, a lever positioned adjacent said link, a pair of electric contacts secured to said lever for selective engagement with the separate electric contacts on the contact member on movement of the lever and contact member in opposite directions relative to each other and speed responsive means engaged with said lever for producing relative movement between the contact member and said lever.

3. A speed responsive switch comprising a rotatable shaft, a movable link rigidly secured to said shaft for rotation therewith, a contact member, means mounting said contact member on the shaft for limited rotation with respect thereto, spring means acting between the shaft and contact member urging the contact member into a predetermined position with respect to said shaft for movement with said link, a pair of separate, spaced apart electric contacts secured to the contact member, a lever positioned adjacent said link, a pair of electric contacts secured to said lever for selective engagement with the separate electric contacts on the contact member on movement of the lever and contact member in opposite directions relative to each other, and speed responsive means engaged with said lever for producing relative movement between the contact member and said lever.

4. A speed responsive switch comprising a movable link, a contact member secured to the link for movement therewith, a pair of spaced apart separate electric contacts secured to the contact member, a lever positioned adjacent said link, a pair of electric contacts secured to said lever located between the contacts on the contact member for selective alternative engagement with a corresponding one of the separate electric contacts on the contact member on movement of the lever and contact member in opposite directions relative to each other, and speed responsive means engaged with said lever for producing relative movement between the contact member and said lever.

5. Structure as set forth in claim 4', wherein the speed responsive means comprises a centrifugal weight assembly acting on one end of the lever and further including spring means engaged with the other end of the lever acting in opposition to the centrifugal weight assembly.

6. Structure as set forth in claim 5 and further includ- 8 ing means for pre-loading the spring means a variable amount for selecting at what speed the lever will be moved by the centrifugal weight assembly.

'7. A speed responsive switch comprising a housing, a pivot pin extending transversely of said housing, a movable link rigidly secured to said pivot pin externally of said housing, a contact member mounted on said pivot pin within said housing, an electric contact secured to said contact member, a lever mounted on said pivot pin within said housing for rotation relative thereto having a contact member secured thereto engageable with the electric contact on the contact member on relative movement between the lever and contact member and a centrifugal speed responsive weight assembly positioned within :said housing engageable with one end of said lever for producing relative movement between said lever and contact member.

8. Structure as set forth in claim 7 including means for providing limited rotation between said contact member :and pivot pin and further including resilient means operable between the pivot pin and contact member for biasing the contact member into a predetermined position relative to the pivot pin.

9. Structure as set forth in claim 7 and further including resilient means engageable with the other end of the lever for determining at what speed movement of the lever relative to the contact member will be initiated by the centrifugal speed responsive weight assembly.

10. Structure as set forth in claim 9 and further including means for selectively pre-loading the said resilient means to vary the speed at which movement of the lever relative to the contact member will be initiated.

References Cited by the Examiner UNITED STATES PATENTS 1,936,993 11/1933 Reed 200- 2,372,274 3/1945 Hoppe. 2,571,869 10/1951 Hanna et a1 200-80 X 2,586,734 2/1952 Sprague et a1. 200-80 2,630,139 3/1953 Nagel 251-129 2,695,936 11/1954 Sparklin 200-80 2,697,581 12/1954 Ray 251-129 2,863,962 12/1958 Letteney 200-80 2,889,817 6/1959 Segerstad 12148 2,910,974 11/1959 Caris. 2,913,921 11/ 1959 Gordon. 2,965,350 12/1960 Knaebel et al 251-129 X 2,966,224 12/ 1960 Teetor -82 2,972,390 2/1961 Bunker et al. 180-82 2,973,051 2/1961 Teetor 180-82 2,983,257 5/1961 Euga 121-48 3,110,852 11/1963 Brucken et a1 200-80 X BERNARD A. GILHEANY, Primary Examiner.

GEORGE HYMAN, 1a., ROBERT K. SCHAEFER,

Examiners.

Claims

4. A SPEED RESPONSIVE SWITCH COMPRISING A MOVABLE LINK, A CONTACT MEMBER SECURED TO THE LINK FOR MOVENENT THEREWITH, A PAIR OF SPACED APART SEPARATE ELECTRIC CONTACTS SECURED TO THE CONTACT MEMBER, A LEVER POSITIONED ADJACENT SAID LINK, A PAIR OF ELECTRIC CONTACTS SECURED TO SAID LEVER LOCATED BETWEEN THE CONTACTS ON THE CONTACT MEMBER FOR SELECTIVE ALTERNATIVE ENGAGEMENT WITH A CORRESPONDING ONE OF THE SEPARATE ELECTRIC CONTACTS ON