US2318671A - Electric switch - Google Patents

Description

May 1l,` 1943. E. M. CLAYTQR 2,318,671

ELECTRIC SWITCH Filed April 2, 1941 2 Sheets-Sheet 2 3 5 v5 40 l Asc-mvo v 7 a /0/ Y Div/0f INVENTOR ATToRNEYf Patented May 11, 1943 ELECTRIC SWITCH Edward M. Claytor, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a.

corporation of Delaware Application April 2, 1941, Serial No. 386,493

(Cl. Zim- 87) 11 Claims.

This invention relates to speed responsive electrical switches and more particularly to air vane switches for use on automotive vehicles for controlling certain electrical devices according to the speed of the vehicle.

It is an object of the present invention to provide an air vane switch of economical, durable and compact construction which provides for the quick make and break of its contacts.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a plan view of the switch with its cover removed.

Fig. 2 is a sectional view on the line 2-2 of Fig. 1 showing the cover in section.

Fig. 3 is a view of the magnet and armature assembly looking in the direction of the arrow 3 in Fig. 1.

Fig. 4 is a fragmentary view partly in section looking in the direction of the arrow 4 of Fig. 1.

Fig. 5 is a, sectional view on the line 5--5 of Fig. 1.

Figs. 6, 7, 8, 9 and 10 are wiring diagrams illustrating various uses of the air switch.

The switch comprises a circular base 28 to which is attached a bushing 2| (Fig. 5) providing the outer race for bearing balls 22, the inner race of which is provided with a shaft 23 having an enlarged portion 24 providing a shoulder 25 which steps down to a portion 26 of less diameter. Shaft 23 is provided with a journal portion 21 having a bearing in the arm 28 of a bracket 29 having a portion 39 joining the portion 28 with a portion 3| parallel to portion 28, the portion 3| being attached to the base 20. The

shaft 23 extends through a packing member 33 and into a bushing 34 fitting on the tapered end of the shaft and clamped by a screw 34a. Bushing 34 provides the hub for a plate 35 shaped to provide an air vane 36 and having an arm 31 carrying a weight 38 which, by adding inertia, stabilizes movement of the vane.

The portion 26 of shaft 23 extends through a hole in a plate 40 and the part 26 is staked against the plate 40 at certain places so that the shaft will drive the plate. Rotation of the shaft 23 in one direction is resisted by a spring 45 coiled around shaft 23 and having one end 46 passed through a hole 41 in part 30 of bracket 29 and having the other end 48 received by one of several notches 49 formed in a flange 50 o1' f the plate 48. Plate 40 carries studs 5| and 52 either of which may engage a lug X of an armature to be described. Since the studs 5| and 52 are spaced a distance greater than the thickness of the lug X it is evident that a lost motion connection is provided between the plate 40 and the lug X. The studs 5| and 52 may be made of Bakelite or Bakelite coated steel rivets so that the parts touching the lug X are nonconducting.

The base 20 insulatingly supports a bracket 60, there being a nonconducting segment 6| interposed between these parts. The bracket which is made of magnetizable metal provides an arm 62 to which two screws 63 attach a magnetizable resilient armature blade 64 carrying a contact 65 and a magnetizable flux carrying block 66 attached by rivet 61 which also secures a conductor strip 68 also secured by the shank of the rivet which provides contact 65.

The armature 64 moves relative to a pole face 10 of a core 1| attached to an arm 12 of the bracket 60 and surrounded by a magnet coil 13 attached at one end to the bracket 60 and attached at the other end to the base 20 in order to provide a ground connection. From the arm 12 of bracket 60 there extends an ear 15 which is provided with a threaded hole for receiving a terminal screw 16 passing through noncon ducting bushing 11 in a cover 18 in order to secure the cover in position with its flange 19 surrounding the peripheral edge of the base 20 as shown in-Figs. 2 and 5 and with its shoulder portion `in engagement with a gasket 8| previously cemented to the base 20. The screw 16 thereforeis a terminal which is common to the armature contact 65 and to thenongroundedendofthecoil13.

. The contact 65 cooperates with av stationary contact xed to an arm 86 of a bracket 81 having a partl88 attachedto the base 28 and insulated therefrom as shown in Fig. 4. Rivets 88a pass through metal plate 88h, insulating plate 88o, base 20,'insulating plate 6| .and bracket part 88. The bracket 81 has an ear 89 provided with a threaded aperture for receiving a terminal screw 98 which, like the screw 16, passes through a nonconducting bushing 9| attached to the cover 18. The screws 16 and 90 therefore provide means for attaching wires to the switch and also for securing the cover 18 to the base 20.

The manner of securing the armature sup'- porting and magnet supporting coil bracket 60 to the base 20 is shown best in Fig. 3. A screw 92 passes through a nonconducting bushing 93 which spaces the screw and insulates it from the bracket 60. The screw 92 passes through the insulating plate 6|, the base 20, a mounting plate 96 and a washer 94 and receives a nut 95. By tightening the nut 95 the bracket 60 and the plate 96 are clamped to the base 20. In a similar manner, plate 96 and bracket 29 are attached to base by a screw 91.

When the spring 45 is arranged as shown in Fig. l, it is biased to cause stud 5| to engage armature lug X in order to close the contacts 65 and 85 as shown diagrammatically in Fig. 6. Fig. 6 illustrates the use of the switch in a circuit including the storage battery and the heater motor of an automobile. Battery |00 is connected by a switch |0| and wire |02 with terminal 90 of the air switch. Terminal 'I6 is connected with the heater motor |02 which is grounded. When the switch |0| is closed, the heater motor |02 is connected with battery |00 through the contacts 65 and 85 of the air switch. When a certain vehicle speed is maintained, it is desirable to `turn olf the motor |02 automatically and this is accomplished by the separation of the contacts 65 and 85 due to the pressure of air from the engine cooling fan impinging upon the vane 36 as indicated by arrow |03. The separation of contact 65 and the contact 85 takes place rapidly due to the fact that the pressure required to overcome the magnetic pull on the armature is considerably greater than that required merely to overcome the spring 45. This spring 45 is first overcome taking up the lost motionfbetween the armature lug X and the stud 52 on plate 40. The pressure of the air acting upon vane 36 tending to rotate it clockwise in Fig. 6 must be great enough not only to overcome the spring 45 but to overcome the magnetic pull afforded by the magnet coil 13 which is also connected with the battery through the contacts 65 and 85. As soon as the pull is overcome the contacts 65 and 85 separate quickly,'because the instant they separate. the coil 'I3 is deenergized and the plate 40 will then move quickly against stop a, said stop being provided by an ear on bracket 29 as shown in Fig. 1. When the vehicle speed air pressure on vane 36 decreases the spring 45 will overcome the air pressure on vane 36, and the contact 65 will reengage the contact 85. At the instant this occurs the coil I3 will be reexcited and will increase the contact pressure between 65 and 85 which is most desirable. In fact the magnetic pull afforded by the electromagnet is great enough to causer the armature spring 64 to bow slightly so that it will seal against the core. The bowing of the spring 64 causes a slight rubbing action by the contact 65 upon the contact 85 which is desirable in order to keep the contacts clean.

As stated before, the spring shown in Fig. 1 biases the plate 49 into contact closing position. If a spring 45X shown in Figs. 4 and 5 is substituted, the plate 40 will be biased into Contact open position, thus holding the contact normally separated from contact 85. The vane 36 can be relocated on the shaft 23 so that air pressure will tend to move the plate 40 into contact closing position as shown in Fig. 7. When the air switch is adapted for making contact under air pressure, it may be used to control some electrical device on the automobile .which is desirable for use when driving at high speed. In Fig. '7 the switch closes with a snap action when a certain high speed is reached and opens with a snap action when the speed falls below a predetermined value.

In the installations shown in Figs. 6 and '7 the air switch is provided with two insulated terminals i6 and 99. This requires that two wires lead from the switch (which is usually located near the front end of the engine under the hood) to the battery and to the heater motor or other electrical accessory. Figs. 8 and 9 show installations similar to Figs. 6 and 7, respectively, except that only one Wire connected with switch terminal 99 is required. The heater motor |02 in Fig. 8 or the electrical device |05 in Fig. 9 is provided with two insulated terminals connected, respectively, with the control switch 0| and with terminal 96 of the air switch. In the installations shown in Figs. 8 and 9, the circuit of the motor or electrical device includes not only the contacts of the air switch, but the magnet winding 'i3 as well. Therefore the magnet winding 'I3 should be of low resistance so as not substantially to reduce the voltage impressed upon the current consuming device. Fig. l0 shows an installation in which the heater motor |02 is connected with a battery ground circuit through a switch ||0 which is normally closed except when the transmission gears are in high or third speed. The heater motor will operate when the switch |6| is closed in low and intermediate speed regardless of the status of the air switch. When the transmission is in high or third speed, switch H9 is automatically opened by means not shown; therefore the air switch controls the stopping of the heater motor when a certain high speed is obtained and restores its operation again when the speed drops back to some lower value.

From the foregoing description ofthe construction of the air switch and the various Ways in which it may be installed, it is apparent that the air switch can easily be adjusted for normally closed contacts opened by air pressure or norrnally opened contacts closed by air pressure. While it is provided with two terminals, it is adapted for use in a circuit where only one of its terminals (terminal is required, the circuit being oompleted when the switch contacts are closed and through the grounded magnet coil of the switch which is used to effect increase of contact pressure when the contacts close and to cause a build-up in operating forces so that the contacts open quickly when the opening force becomes eective.

The armature 64 and parts supported thereby divide the switch compartment into two parts. The par-t to the left of armature 64 (Fig. 1) is occupied by shaft 23, bracket 29 and biasing spring 45 or 45X. The part to the right of armature 64 is occupied by bracket 6 magnet core 1| magnet coil 'F3 and by bracket 81. The space within the case 'I8 is therefore used to the best advantage. For automobile use, the switch can be made small and compact. In fact the switch is much smaller than shown in the patent drawings.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

l. An electric switch having a magnetizable resilient amature blade carrying a contact, a stationary contact engaged thereby and connected with a terminal, means for controlling the position of the blade with respect to its contact mak ing-and-breaking status, and electromagnetic means for retaining the blade in contact making' position and including a magnet coil, a core, a-

magnetizable bracket supporting the core and one end of the amature blade;and a flux carrying, block attached to the armature near its xed end.

and on the side thereof remote from the core;

thus permitting the armature blade to seal against attached to the base; a flexible armature extend.`

ing between the shaft and the brackets, said amature having one Aend fixed to one of the brackets and having its free end provided with a contact for engagement with a stationary contact carried by the other bracket, at least one of the contacts having a convex surface; a plate fixed to the shaft and having provisions cooperat- Y ing with the armature to open and close the contacts; an eleotromagnet for attracting the armature and including a magnet coil and a core carried by the bracket to which the armature is attached; a flux carrying block attached to the flexible armature and on the side remote from the core face, thus permitting the armature to bend toward the core face so as to change the relation of the contacting surfaces of the contacts when the magnet coil is energized.

3. An electric switch comprising in combination; a base; a shaft journalled in a bearing provided by the base, said shaft being located on one side of a medial line of the base: a pair of mounting brackets attached to the base on the other side of the medial line of the base; a flexible armature extending substantially along the medial line and having one end secured to one of the brackets and having its free end provided withy a contact adapted to engage a stationary contact xed to the other mounting bracket, at least one of the contacts having a convex surface; means fixed to the shaft and operable upon the amature to open and close the contacts; electromagnetic means for attracting the flexible armature in contact making position and including a magnet coil, and a core carried by the bracket supporting .the armature; a flux carrying block attached to the armature and on the side remote from the core and thereby permitting the armature to bend and seal against the face of the core so as to shift the engaging portion of the contacts when the magnet coil is energized. f

4. An electric switch comprising in combination; a base; a shaft journalled in a bearing provided by the base and in a bearing spaced from the base and supported by a bracket attached to the base, said shaft being located on one side of a medial line of the base; a pair of mounting brackets attached to the base on the other side of the medial line; a flexible armature extending substantially along the medial line and having one end secured to one of the mounting brackets and having its free end provided with a contact adapted to enga-ge a stationary contact fixed to the other mounting bracket, said other mounting bracket supporting an electromagnet having a coil connected with the armature; a flux carrying block carried by the armature and on the side remote from the core of the electromagnet whereby the flexible armature will bend when the magnet coil is energized causing the movable contact to slide over the face of the stationary contact.

5. An electric switch comprising in combination; a base; a bearing carried by the base on one side of a medial line; a support having a flange provided with a bearing in alignment with the base bearing; an actuating shaft journailed in the bearings; a pair of mounting brackets supported by the base on the other side of the medial line; a resilient armature extending substantiallyalong the medial line and fixed at one end to one of the mounting brackets and carrying a contact at its free end adapted to engage normally a stationary contact carried by the first mentioned bracket having a coil connected with the armature; means for actuating the shaft in one direction of rotation; a drive plate movable with Ithe shaft for moving the armature to separate the contacts; yieldable means for resisting the movement of the shaft in said one direction and operating to move the shaft through the drive plate in the opposite direction as the shaft actuating means is reduced; an enclosure for the base, support and the brackets; and means for securing the enclosure to the brackets, said securing means operating as terminals for the switch.

6. An electric switch comprising, a base and a cover providing a compartment; a mounting bracket of magnetizable metal supported from the base; a resilient armature blade extending across the compartment and fixed at one end to the mounting bracket and carrying a contact at the other end; armature retaining means in the compartment on one side of the armature, said retaining means comprising an electromagnet having a core extending from the bracket and y having a coil connected with the armature; a support on the same side of the armature with the magnet and carrying a contact engageable with the armature contact and providinga terminal for the switch; a magnetizable plate secured to the armature near its fixed end, thus permitting the armature to seal against the pole face of the core and permitting the armature portion projecting beyond the magnetizing plate to bend and thereby produce a wiping action between the contacts when the electromagnet is energized; and means journalled in the base and on the other side of the armature for controlling the position of the armature.

7. An electric switch comprising, a base and a cover providing a compartment; a mounting bracket of magnetizable metal supported from the base; a resilient armature blade extending about midway across the compartment and ilxed at one end to the mounting bracket and carrying a contact at its free end; armature retaining means in the compartmentV on one side of the armature, said retaining means comprising an electromagnet having a core extending from the bracket and having a coil vconnected with the armature; a support on the same side of the armature with the magnet and carrying a contact engageable with the armature contact and providing a terminal for the'switch; a magnetizable plate secured to the armature near its fixed end, thus permitting the armature to seal against the pole face of the core and permitting the armature portion projecting beyond the plate to bend to produce a wiping action between the contacts when the electromagnet is energized; and means for controlling the position of the armature, said means including a shaft journalled in the base: means for actuating the shaft in one direction of rotation; means carried by the shaft for 'transmitting motion fromv the shaft to the armature; and resilient means engaging said shaft carrying vmeans so as to apply a force to said carrying means in opposition to .said actuating means.

8. An electric switch comprising, a base and a cover providing a compartment; a mounting bracket of magnetizable metal supported from the base; a resilient armature blade extending about midway across the compartment and fixed at one end to the mounting bracket and carrying a contact at the other end; armature retaining means in the compartment on one side of the armature, said retaining means comprising an electromagnet having a Vcore extending fromA the bracket and having a coil connected with the armature; a support on the same side of the armature with the magnet and carrying a contact engageable with the armature contact and providing a terminal for theswitch; a magnetizable plate of lesser dimension than vthe armature secured to the armature-in a manner to permit-'the armature tobend and produce a wiping action between the contacts when the electromagnet is energized; a shaft journalled in the base; nuid actua-ted means for rotating the shaft in one di; rection or" rotation; a plate carried by the shaft having 'provisions for operating the armature; and Aisp'ring means cooperating with the plate for resisting movement of the shaft in said one directionand operating to move the shaft in the opposite direction as the fluid actuated means is reduced. 9. A switch of the type described comprising,

a support, a shaft rotatably carried by the sup'- port; a pair' of'spaced abutments movable with thefshaft; a fiexible armature having one end x'ed relative to the support and having its free end so positioned that it will be located between the abutments; normally spaced contacts, one of said contacts being movable with the armature; spring means for `urging the shaft in one direction whereby one of the abutments engages the armature to hold normally the movable contacts out off engagement with the other contact; fluid means for rotating the shaft in the opposite direction and causing the other abutment to bias the armature to urge the movable contact into engagement with the other contact; an 'electromagnet having a coil electrically 'connected with one of the contacts; anda iiux carrying member carried by the armature and so arranged with respect thereto to permit the nexible armature to bend upon energization of the coil so as to change the relation of the contacting `surfaces of the contacts.

10. An electric switch comprising in combination; Va rotatable shaft; fluid actuated means for the shaft; a flexible armature having one end fixed and having a contact at the other end; a stationary contact; an electromagnet including a core and a winding; an energizing circuit for l' the winding including said contacts; means movable with the shaft to bend the armature and move its contact into engagement with the stationary contact causing the winding to be energzed whereby the magnet core will exert ia force to distort the armature and thereby causethe armature contactto shift the point of engagement; means for actuating-the shaft in one direction; and -resilient means for resisting movement of the shaft in said one direction.

11. `An electric switch comprising in combination; a rotatable shaft; fluid actuating` means for the shaft; a iiexible armature having one end fixed and having a contact at the other end; a stationary contact; an electromagnet including a core and a winding; an energizing circuit for said winding including said contacts; devices on opposite sides of the armature and movable With the shaft, one of said devices operating to move the armature contact into engagement with the stationary .Contact when the shaft is rotated in one direction by the fluid actuated means causing the winding to be energized whereby the magnet core will exert a force to distort the armature and causing the armature contact to slide over the stationary contact to change the point of engagement; spring means for resisting. the movement of theshaft, said spring means operating to rotate the shaft in the opposite direction as the iiuid actuating means is reduced to cause the other device to move the armature and separate the contacts.

EDWARD M. CLAYTOR.

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