US2489736A

US2489736A - Automobile circuit control

Info

Publication number: US2489736A
Authority: US
Publication date: 1949-11-29
Anticipated expiration: 1966-11-29

Description

Nov. 29, 1949 c. H. ANGUS 2,489,736

AUTOMOBILE CIRCUIT CONTROL Filed Margg 14, 1946 INVENTOR I r11 CHARLES H. ANGUS BY ILL/M 14 ATTORNEYS Patented Nov. 29, 1949 UNITED STATES PATENT OFFIGE 13. Claims.

This invention relates: to automatic controlling;

devices for electrical circuits or automotive:- conveyances. v

' The present invention isimor'ez particularly? con:-

cerned with: an: automatic: circuit: control havingi thev same general purptxsei f butt representing an.

improvement: over that illustratedv and. described in my- Pat'eniz Noe 2;Ii43;906, issued January 17,.

1939, and. this application; is; a; continuation: in part of; my: copending: application Serial; No; 6'I8;6LL,.filed September 26, .1'945, nowzabandoned.

In the circuit controlling'tdevice. of the abovereferred-to patent}. switch: contacts were:- operated by ant air-operated member: which was ins turn actuated; as a. resultsof the vacuumbuilt up. in the intakez of; the: engine, the switch. contactsbeing connected so; as to; automatically open: thev electrical circuits ofthecar immediately upon the; engine coming to a standstill and therebygprevent waste: of the? battery current shouud. any of the electrical devioesof the. can be: inadvertently left connected. In thisldevice, a dashpot effect was; obtainable.- as. a consequence-of making; the air Operated member in the form of.- a; pivotally mounted-.vane;, therefore fluttering of the vane andi undesired opening; of the. circuit.- was prevented duringmomentary variation or. reductions of the vacuuminthe. engine intake, such as are occasionedwhen thercar 'was proceeding up a hill; under heavy=-load=. Thisvdevicemperated satisfactorily, butirequired. care: in use,- and;- was somewhat costly inmanufacture: due to the packing requiredabout the vane-.

According-tothe:present invention an improved automatic. pneumatic-operated: switch deviceis provided: wherein: no: packing; between. moving; parts; is. required; so, that thermanufacturing; and maintenance. costs are: reduced, and; yet the: device operates to: prevent fluctuations and break.- ing of theautomotivecircuits: during; the short periods that the. engine-intake: vacuum: is; reduced' while the: engine: is: running; orcut ofizifi the engine shouldstalL. This 1 is. accomplish'edby the' provision. of a unitary device having: struct'ure forming-.apair of:- separataair-ti'ght, intercennectedi chambers ofi difierenti size, one being larger relatively and functioningas:aballast, and the smaller chamber'having 'a simple pressure; responsive' or air=operated member, comprising a diaphragm in' the embodiment of the invention illustrated herein,. whichrequires no costly airtight packing; and has" a long, useful, troublefree 11m The diaphragmisextremely'economical to fabricate, simple" to'mount without danger of alr leakage, and simple'toadapt forswitch operations By" the use-oftl'ie' large ballast chamber-,- to gether with a vacuum-'mainta-iningvalve; fluttering' of thediaphragm and switch means; which would undesirably open the circult; is eliminated;

and also short-lived loss ofivacuum from the. en.-

gine, as for instance when the. engine stalls, will. not open. the. circuit, since. a substantial interval.

of time is required, onthe order of two or threev minute's to reduce the vacuumv in the ballast chamber becau'seof. itsilargesize andthe substan-- tially tight jointsiemp'loyed;

Alnovel meansis'provided for varying; and adjusting. thelrat'ezof air admission into the ballast chamber: whenthe engine is shut. 0fi,.thereby to adjust the time required: by. the device to. open theicircuitl This'means. comprises an. adjustableneedlavalve interposedlbetween the ballast chamber: an'dsthe. vacuum: line,.the valve:being located; together with the air: exhaust valve of the chamber;.in a. fitting. secured to the chamber; The fitting; carrying, the: valve has a removable combination cap and nipp1e,.the nipple connecting with a vacuum hose leadingv from the car intake, and; the cap serving, to enclose. both the, needle valve and the. air exhaust valve. The organization as above-set forth has. the'advantage that the same fitting can be used. for both valves, eliminating; the use of an. extra fitting, and that there is eliminated the possibility of. dirt or other foreign matterreaching, the valves andimpairing their: operation" In. addition,.. there. is no admission of air whatsoever: through the. needle valve into: the-ballast. chamber when the engine is running; since the needle;- valve: does not communicate with the outside; atmosphere, but instead communicates. withithe car intake; Also; theadjustablerneedle. valve'is readily accessible-after the device. is completely assembled. except. for' the nipple cap, so that-the valvecanbe conveniently adjusted: at the factory to properly set each device y'ettamperin'g with the valve after the device leaves the factory is discouraged, due to its being". covered and: hidden: by the cap.

In conjunction with the improved swltchdeviceof this-invention, a, manually operable switch and: signal means are provided so'that' the automatic-controlling device may berendered inoperative at will, thereby becoming ineffective to openithe oar circuits, and se'that an operator'will bei apprised of such condition, and will not inadverentl'y leavethe car with the device in the inoperative stateunless'so desired.

Other features and advantages will hereinafter appear;

In the accompanying drawings:

Figure 1 is a schematic view ofan automobile having the improved circuit-controlling device of the inventiorr installed therein;

Fig-J 2i's' a-n axialsectionthrough the'automatic pneumatic circuit-controllingdevice of the" inventlon;

Fig. 3'is atop'vi'ew-of the circuit-controlling device; and

Fig. 4' is adia'grammatic view ofthe automobile electrical circuits and the circuit-controlling device of the invention connected therewith.

Referring to Figs. 2 and 3, the pneumatic circuit-control device of the present invention comprises a housing It which is so constructed as to form a pair of separate, air-tight, interconnected chambers II and I2 of different size, the chamber I I being relatively larger and functioning as a ballast, and the smaller chamber I2 being associated with a simple, leak-proof pressure-responsive means coupled with switch means, all for reliably controlling the car circuits in a particular and advantageous manner.

In the specific structure at present preferred and shown herein as illustrative of the invention, the housing It] comprises a body I3 in the form of a cylinder having a bottom closure I4 and a top closure I5, the latter having the shape of a shallow cup with thick side walls I6.

The ballast chamber I I is thus defined by the closures I4 and I5, and embraces substantially the entire interior of the body I3.

The housing It also comprises a cap portion i! in the form of a shallow cup having thick side Walls I8, the cap being inverted and securedto and over the closure Iii by means of screws I9 passing through the side walls of the cap and closure.

Interposed and clamped between the cap I1 and the closure 15 is a pressure operable diaphragm 25 which may be formed of any suitable air-tight material which will yield or fiex under air pressure. I have found that a rubberized fabric material may be advantageously used for making the diaphragm 20, since this material serves as an air-tight seal or gasket where it is clamped between the walls It and I8 of the closure and cap, as well as being impervious to air and extremely flexible itself.

The side walls It and I8 of the closure I and cap ll have aligned channels 2I and 22 respectively, and the diaphragm 26 has an aperture where the said channels meet, to enable these to communicate with each other.

The channel 22 has an angularly extended portion 23 opening into the chamber I2, and thus the latter is connected with the ballast chamber I I.

Also, the side wall It of the closure I5 has a channel 24 aligned with an aperture 25 in the wall of the body l3, the said channel and aperture constituting a vent to the atmosphere.

By this construction variations of pressure in the ballast chamber Ii will result in corresponding pressure variations in the chamber I2, causing movement of the diaphragm 26 either upward or downward.

As shown in Fig. 2, the side wall of the body I3 is provided with an air outlet fitting 26 which may be soldered to the said wall to form an airtight seal thereto. A spring-urged valve 21 which may comprise a standard tire valve is mounted within the fitting 2B, the Valve being so constructed that it permits air to be removed from the chamber II, but prevents the intake of air into said chamber.

The fitting 26 is externally threaded to removably carry a cap 28 formed at its end into a nipple 29 which is connected by a flexible hose 3G with the intake 3| of the automobile engine 32. The fitting 26 has an exterior flange or shoulder 33, and a gasket washer 34 is provided between the shoulder 33 and the end of the cap 28 to seal the latter to the fitting. Thus when the engine 32 is operating, air will be sucked out of the ballast chamber I I and a partial vacuum will be created therein. This vacuum will be sustained regard- 4 less of momentary fluctuations of the suction or intermittent cessation of suction, due to the substantial size of the chamber and to the provision of the spring-urged valve 21.

The ballast chamber II being in communication with the chamber I2 will cause a partial vacuum to exist within the latter. Since the chamber 35 between the diaphragm 2i and the closure I5 is vented to the atmosphere, atmospheric pressure is brought to bear aaginst the underside of the diaphragm 29 so that the latter is moved upward when the partial vacuum exists in the chamber I2.

For the purpose of controlling the automobile circuits, the cap I? of the casing Iii is provided with contact-carrying means in the form of studs 36 and 31 which extend through apertures in the walls of said cap, the studs being insulated from each other by making the cap of Bakelite or other insulating material. The stud 36 passes through the center of the cap I'i, and at its inner end is provided with a stationary contact 38 adapted to engage a movable contact 39 secured to the end of a resilient arm lll mounted on the inner end of the stud 3?. Connections may be made to the studs 36 and 31 by wires M and 42 respectively in the usual manner as shown.

Normally the resilient arm is biased so as to maintain the contact 32 separated from the stationary contact 38. However, when the diaphragm 2!! is forced upward, due to a vacuum existing in the chambers II and I2, it causes the arm so to flex so as to bring the contacts 38 and 39 together.

Preferably the diaphragm 28 at its center is I provided with a button 43 riveted thereto and adapted to engage a rivet head 44 on the arm Ml, so as to prevent wearing away of the material of the diaphragm.

Because of the structure and arrangement of the chambers II and I2, valve 21 and diaphragm 28 and with the particular sealing means employed therewith, the partial vacuum in the said chambers will be maintained at a level which is sufiicient to hold the switch contacts 38 and 39 closed over a period of time normally in excess of five minutes after the car engine has stopped, and this is an important advantage of the circuit control since it prevents immediate opening of the car circuits if, for example, the engine should stall before the car when being halted is finally brought to a standstill. Therefore, in a sense, the automatic switch of this invention functions as a time-delay switch, although no clockwork or other movable timing means is employed.

According to the present invention novel means are provided for enabling'reliable adjustment of the switch to be made so that the time delay may be in the order of two to three minutes. This adjustment means is extremely simple and fool proof, and is so organized that dirt and other foreign matter cannot reach it. Therefore, after initially adjusting the said means to attain the desired time delay of two to three minutes, it is not necessary at any later date to readjust it due to impairment in its functioning.

The adjustment means comprises an adjustable valve which is constructed to minutely admit air into the ballast chamber II after the car engine has ceased to turn over, and the intake vacuum has ceased. Preferably, according to the invention, the adjustment valve is-so located as to bypass the one-way valve 21 in the fitting 25, and for this purpose the fitting is made of comparatively large diameter.

7 Referring to Fig. 2, the fitting '26 has a bore 45 having an enlarged threaded portion 46 which carries a screw '4'! adjustable in the bore and locked to the fitting by a lock nut 48. The screw 41 has a conical end 49 fitting a conical seat 50 of the bore 45, and the tip 49 or" the screw has apertures 5| communicating with a central bore 52 passing through the screw and through the head 53 thereof.

The screw 41 may be so adjusted that when a vacuum exists in the ballast chamber H but no vacuum exists within the ca 28, air may ass through the bore 45 into the chamber H at a minute rate, this rate being such that in a period of approximately two to three minutes the vacuum in the chamber I l is broken sufiicie'ntly to release the diaphragm '29 and allow the contact points 38 and '39 to separate from each other.

It will be noted that the valve screw 41 is entirely enclosed Within the cap 28 of the fitting 26 and also by the body l3. Since the ballast chamber II has no exposed outlet to the atmosphere, no dirt can get into the chamber, and since suction only is applied through the housing 30 to the cap 2 8 and fitting 26, dirt is prevented from entering the cap and impairing the operation of either the valve 21 or the valve 49, 50. When the engine 32 is shut off, the vacuum in the intake 31 and in the housing 30 and cap 28 ceases, and since an is present Within these parts as a result, a small quantity of this air will be sucked through the screw 41 and bore 45 into the ballast chamber H to break the vacuum therein.

The locating of the valve screw 41 in the fitting 26 has the advantage that the time delay of the device may be adjusted at the factory after the entire assembly has been completed, since it is a very simple matter to quickly remove the cap 28 and adjust the screw 41. However, since the screw is completely covered and concealed by the cap 28, the danger of tampering with the screw is minimized after the device leaves the factory. Also, by locating the screw 41 in the fitting 26, the necessity of having a second fitting solely for the adjusting valve of the device is eliminated.

When the engine 32 is operating and suction is being applied to the cap 28 the adjusting valve does not function to admit air into the ballast chamber I I since the valve does not communicate with the atmosphere but instead with the interior of the cap.

Referring to Fig. 4, the circuit diagram of the automobile includes head lamps 54 and a tail lamp 55, all having a common wire 56 connected to the light switch 51 of the car. The other terminals of the head and tail lights are connected to the ground as indicated. The light switch 5! is connected by a wire 58 to the ammeter 59 whose other terminal is connected to the wire 42 leading from the terminal stud 31 of the automatic switch. The wire 4| from the terminal stud 36 of the automatic switch is connected with the battery 60, whose other terminal is grounded.

From the ammeter 59 a wire '61 may lead through aswitch 62 to a windshield heater 6'3, and a wire '64 may lead through an ignition switch 65 to an ignition coil 66 whose other terminal is connected through the distributor rotor 61 to the ground.

According to the present invention the automatic control system for the car is provided with a'manually operable switch and signal means, the manual switch being connected in parallel with the automatic switch, and the signaling means operating to indicate when the manual switch is closed. for which condition the automatic switch is rendered ineffective. As shown in Figs. 1 and 4, a signal bulb E8 is provided, the bulb being connected by a wire 69 to the ground, and by a wire in to one terminal of a manually operable switch H the other terminal of which is connected by a wire 12 to the 'wire 42. Also, a third terminal of the switch H is connected by a wire 13 to the 'wire 4i.

When the handle of the switch ii is depressed, the wires '19 and '53 are simultaneously connected with the wire 12, thereby shunting the contacts 38 and oi the automatic switch and connecting the signal bulb 68 so that the latter is energized from the battery 60.

The operation of the control of this invention is as follows: Normally the manually-operative switch ii is left open, in the position shown in Fig. 4. When the engine 31 is to be started, the ignition switch 65 is closed, and the engine turned over by the starter. The suction thus created in the intake all will create a partial vacuum in the ballast chamber H of the housing l0, and a vacuum in the chamber 12. This will immediately move the diaphragm 29 upward, causing it to flex the resilient arm 40 and bring together the contacts 38 and 39. Thus the battery 50 will be connected through the ammeter 59 to the ignition circuit, so that the engine will receive spark for starting. Also, the other circuits of the car including the lighting, defrosting circuits, etc., will be available for use, and may be energized if their individual switches are closed. It will thus be seen that in starting the engine the igniticn switch is closed by the operator inserting the key in the car in the usual manner, and upon the engine being turned over by the starter the 'auto matic switch of the invention will immediately connect the battery to the ammeter 59 so as to render the car circuits available for use.

Therefore, an operator proceeds in running and operating the car just as if the automatic switch were not present, since its operation is entirely automatic. However, when an operator is ready to leave the car and the engine is shut off, or even if the engine should stop Without being shut off, the switch will automatically operate after a short period of time on the order of two to three minutes to disconnect all the circuits of the car from the battery by the contacts 38 and 39 separating the arm 49 moves the diaphragm 20 downward in consequence of the vacuum in the chambers l I and I2 ceasing.

Thus it will be seen that if the operator has left connected any of the devices such as the defroster etc., these will be automatically disconnected and will not cause a drain on the battery 69 when the car is left parked. Also, the head and tail lights of the car will automatically shut off.

If for some reason, it is desired to leave the head lights and tail lights burning, the manually operable switch H may be closed upon leaving the car to bridge the automatic switch and thereby render the latter ineffectual in disconnecting the battery, and an operator will be apprised of the .fact that the switch "H is closed by the signal bulb 68 becoming illuminated for such condition.

According to the above structure as provided by the invention, when the car is in operation fluctuations in the suction of the intake 3| will not result in the car circuits being inadvertently opened, since a substantial reserve vacuum is carried in the ballast'chamber H of the housing.

For instance, if the car is being driven up a long hillthe reduced vacuum in the intake 3|, which is prolonged in accordance with the length of the hill, would not result in the diaphragm 20 being released causing undesired separation of the contacts 38 and 3s, and opening the car circuits. Also, since the vacuum in the ballast chamber l I and the vacuum chamber i2 is maintained for a period of approximately two or three minutes after the engine stops, delaying the release of the diaphragm 20 and disconnecting of the car circuits, no trouble would be experienced if, for instance, the engine stalled during parking and before the car came to a complete standstill.

. It will be seen that a simple and compact, stabilized or non-fluttering automatic switch device is thus provided by the invention without resorting to a dashpot efiect, and to pressureresponsive or air-operated means requiring packings, etc., as with pistons, vanes and the like, and that the efiect of a time delay is obtained through the use of the ballast chamber I I, such delay being appreciable to the extent of overcoming, for instance, the reduced intake-vacuum encountered when the car is made to climb hills.

For the purpose of mounting the automatic switch of the invention a bracket is provided in the form of a strap M which encircles the body H, the end portions of the straps being secured together by a screw and having apertured ears l5 for receiving suitable mounting screws (not shown).

Variations and modifications may be made within the scope of this invention and portions of the improvements may be used without others.

I claim:

1. In a pneumatic-operated circuit controller for use with the intake of an internal combustion engine, an air-tight chamber; a substantially leak-proof pressure-operable member connected with the chamber and preventing leakage of air into the latter, said member responding to changes of pressure in the chamber; switch means operated by the pressure-operable mem ber; an air fitting connected to the chamber; a removable cap for said fitting, the said cap having a nipple for connection with the intake of the engine to produce a vacuum in the chamber; a one-way valve in the air fitting, passing air solely out of the chamber; and an adjustable valve in the air fitting, bypassing the one-way valve and minutely admitting air into the chamber to break the vacuum therein within a predetermined time after the engine is shut off, thereby to cause operation of the said switch means, the said valves being enclosed and concealed by the said chamber and removable cap and nipple, and the adjustable valve having a manually operable part contained within the cap and exposed only when the cap is removed from the fitting, thereby to minimize the likelihood of tampering with the adjustment of the valve.

2. In a pneumatic-operated circuit controller for use with the intake of an internal combustion engine, a unitary assembly comprising a relatively large air-tight chamber; means including a leak-proof pressure-operable diaphragm,

forming a relatively small air-tight chamber located exteriorly of the large chamber, said large and small chambers permanently communicating with each other and the small chamber having a volume which is a small fraction of thelarge chamber and the said pressure-oper- V able diaphragm responding to changesof pressure in the small chamber; biased switch means located in the small chamber and operated by the diaphragm; an air outlet connected to the large chamber, for connecting the latter with the intake of the engine to produce a vacuum in the chambers; a one-way valve in the air outlet, passing air solely out of the large chamber; and a second Valve in the air outlet, bypassing the one-way valve and'minutely admitting air into the large chamber to break the vacuum in the chambers within a predetermined time after the engine is shut on, thereby to cause operation of the said switch means.

3. A pneumatic-operated circuit controller for use with the intake of an internal combustion engine, comprising a housing having a substantially air-tight ballast chamber; a pressure operable member mounted externally of the chamber; means, forming with the operable member a second substantially air-tight chamber; means forming an air passage between the said chamber; switch means in said second chamber, controlled by the pressure-operable member; an air outlet for the ballast chamber, for connection with the intake of the engine to produce a vacuum in said chamber and operate the pressureresponsive member; and means associated with said air outlet for maintaining the latter closed against flow in the direction to prevent passage of air into the chamber, the vacuum in the latter being sustained during periods of no suction or reduced suction in the engine intake, and holding the pressure-responsive member and switch means steady.

4: A pneumatic-operated circuit controller for use with the intake of an internal combustion engine, comprising a housing having a substantially air-tight ballast chamber; a pressure operable member mounted externally of the chamber; mean, forming with the operable member a second substantially air-tight chamber; means forming an air passage between the said chambers; switch means located within said second chamber, controlled by the pressure-operable member; an air outlet for the ballast chamber, for connection with the intake of the engine to produce a vacuum in said chamber and operate the pressure-responsive member; means, associated with said air outlet for maintaining the latter closed against flow in the direction to prevent passage of air into the chamber, the vacuum in the latter being sustained during periods of no suction or reduced suction in the engine intake, and holding the pressure-responsive member and switch means steady; and adjustable means for minutely admitting air into the said ballast chamber to break the vacuum therein within a predetermined time after the engine is shut off, thereby to cause the said switch means to be operated.

5. A pneumatic-operated circuit controller for use with the intake of an internal combustion engine, comprising a housing having a substantially air-tight ballast chamber; a pressure operable member mounted externally of the chamber; means, forming with the operable member a second substantially air-tight chamber; means forming an air passage between the said chambers; switch means controlled by the pressureoperable member; an air outlet fitting for the ballast chamber, including a removable cap on said fitting for connection with the intake of the engine to produce a vacuum in said chamber and operatethe pressure-responsive member; means associated: with said air outlet for maintaining the-latter: closedagainst flow in the direction to prevent passage of airintothe chamber, thevacuumsin thelatter being sustained during periods of, no suction or reduced suction in the engine intake, and holding the pressure-responsive member and switch meanssteady; and adjustable means located in. the said air outlet, and including. a manually operable part within said cap,.for. minutely admittin air into the said ballastchamber after the engine is shut off, thereby. to breakv the vacuum. in the chamber within a. predetermined. time and cause operation of the.- saidswitchmeans', saidv part being exposed for adjustment when the. cap. is removed from the fitting.

6. A pneumatic operated circuit controller for use with theintake maniioldof an internal combustion. engine. comprising a housing having a substantially air-tight ballast chamber; a pressure-operable member. mounted on. the. housing exteriorly of the chamber; means, mounted on thehousing, forming with the pressure operable member a second substantially air-tight chamber; means forming an air passage between the said chambers; switch means in said second chamber, controlled by the pressure-operable member; an air outlet for the ballast chamber, for connection. tothe' intake manifold of the engine toproduce a Vacuum insaid chamber; and a. valve associated with said. air outlet for pre venting passage of air f'romtheintake manifold into the chamber, the vacuum inthe latter being sustained during periods of no suction or. reduced suction in the manifold, and holding the, pressure-responsive member and switch. means steady;

7. In a suction-controlled circuit controller for automobiles, a switch havingfixed and movable contacts;.a chamber; a diaphragm dividing. said chamber into a high pressure side which communicates with the atmosphere, and a low pressure side in which said contacts are disposed, said diaphragm causing the movable contact of the switch to engage the fixed contact when a partial Vacuum exists in the low pressure side; and a ballast chamber of large capacity communicating with the low pressure side of the switch chamber, said ballast chamber having an exhaust opening and an exhaust conduit adapted to be connected to the engine intake whereby a partial vacuum is created in said ballast chamber, and having a spring valve in the exhaust opening preventing air from entering the ballast chamber, whereby the vacuum causing the switch to remain closed is sustained for a predetermined time when suction from the engine is reduced or ceases as by laboring or stopping of the engine.

8. A pneumatic-operated circuit controller for use with the intake manifold of an internal combustion engine, comprising a housing having a substantially air-tight ballast chamber; a diaphragm mounted in the housing exteriorly of the chamber, said diaphragm and housing forming a second substantially air-tight chamber between them having a volume which is a smallfraction of the ballast chamber; means forming a permanent air passage between the chambers; switch means operable by the diaphragm; and means for connecting the ballast chamber to the intake manifold of the engine to produce a vacuum in said chamber, said means including a valve for preventing passage of air from the intake manifold into the chamber, the vacuum 110 in the latter being sustained during periods of reduction of. the vacuum in the manifold and holding the diaphragm and switch means steady.

9. A pneumatic-operated circuit controller for use with the intake manifold of an internal combustion engine, comprising a housing having a substantially air--tight ballast chamber; a diaphragm mounted in the housing exteriorly of the chamber, said diaphragm and housing forming a second. substantially air-tight chamber between them; means forming an air passage between the chambers; switch means disposed in the second chamber, operable by thediaphragm; means for connecting the ballast chamber to the intake manifold of the engine to produce a vacuum. in said chamber, saidmeans including a valve for preventing passage of air from the intake manifold into the chamber, the vacuum in the latter being sustained during periods of reduction of thevacuum in the manifold and holding the diaphragm and switch means. steady; and a second valve bypassing thev first-mentioned valve, said second valve minutely admitting air intothe bale last chamber after the engine is shut off, and breaking the vacuum in. the chamber within a predetermined time to cause operation of the said switch means.

10.: A pneumatic-operated circuit controller for use with the intake manifold of an internal combustion engine in an automobile, comprising an.elongate housing for mounting on a. supporting surface of the automobile, said housing having a. transverse wall dividing it into a relatively small air chamber and a relatively large air chamber; a diaphragm extending transversely across the small chamber and dividing the latter into two parts, one of said parts adjacent the said transverse wall of the housing communicating with the atmosphere and the other part communicating with the relatively large chamber of the housing; switch means located in the said other part of the small chamber and controlled by the said diaphragm; an air outlet communicating with the large chamber of the housing, said outlet being adapted for connection with the engine intake to produce a vacuum in the said large chamber; and a valve associated with the air outlet, preventing air from entering the said large chamber and sustaining the vacuum in the chamber during periods of no suction or reduced suction in the engine intake, thereby to hold the diaphragm and switch means steady.

11. A pneumatic-operated circuit controller for use with the intake manifold of an internal combustion engine in an automobile, comprising an elongate housing for mounting on a supporting surface of the automobile, said housing having a transverse wall dividing it into a relativelysmall air chamber and a relatively large air chamber; a diaphragm extending transversely across the small chamber and dividing the latter into two parts, one of said parts adjacent the said transverse wall of the housing communicating with the atmosphere and the other part communicating with the relatively large chamber of the housing; switch means located in the said other part of the small chamber and controlled by the said diaphragm; an air outlet communicating with the large chamber of the housing, said outlet being adapted for connection with the engine intake to produce a vacuum in the said large chamber; a valve associated with the air outlet, preventing air from entering the said large chamber and sustaining the vacuum in the chamber during periods of no suction or reduced diaphragm and switch means steady; and an adjustable valve bypassing the first-mentioned valve and minutely admitting air into the large chamber to break the vacuum therein within a predetermined time after the engine is shut off, thereby to cause operation of the said switch means.

12. A pneumatic-operated circuit controller for use in an automobile with the intake of an internal combustion engine, comprising an elongate cylindrical housing for mounting on a supporting surface of the automobile; a pair of shallow circular cups secured together at their lips to form a closed chamber, one of said cups being mounted on the end of the housing to seal the latter, and having a vent to the atmosphere; a diaphragm mounted between the lips of the cups, dividing the said chamber into two parts; electrical switch means mounted in the unvented cup, operable by the diaphragm, the said cups having aligned channels connecting the interiors of the unvented cup and housing; an air outlet communicating with the interior of the housing, for connection with the engine intake to produce a vacuum in the said housing; and a spring-urged valve located in said air outlet for preventing passage of air into the housing, the vacuum in the latter being thereby sustained during periods of no suction or reduced suction in the engine intake, thereby to hold the diaphragm and switch means steady.

13. A pneumatic-operated circuit controller for use in an automobile with the intake of an internal combustion engine, comprising a cylindrical, elongate housing adapted to be mounted on a supporting surface of the automobile; a closed cylindrical casing secured with one end closing an end of the housing to seal the latter, the said casing projecting from the end of the housing; a circular diaphragm stretched across the interior of the cylindrical casing, dividing the latter into a posterior cylindrical chamber and an anterior cylindrical chamber, said posterior chamber having a vent to the atmosphere; electrical terminal studs insulatedly mounted in the walls of the cylindrical casing, said studs extending into the anterior chamber; contacts secured to the studs within the chamber, one of said contacts being movable and adapted to be operated by the said diaphragm; a fitting secured in a wall of the said housing, for connection with the intake manifold of the engine, said fitting having a valve for preventing the passage of air into the housing; and means forming, an air passage between the anterior chamber of the cylindrical casing and the chamber of the housing, the volumetric size of the latter, and the said valve operating to maintain the diaphragm and movable contact steady during fluctuations of the suction in the intake of the engine.

CHARLES H. ANGUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,628,209 Wilcox May 10, 1927 1,866,068 West et a1 July 5, 1932 1,984,736 Garoutte Dec. 18, 1934 2,061,079 Lacoe Nov. 17, 1936 2,143,906 Angus Jan. 17, 1939 2,182,816 Moffett Dec. 12, 1939 FOREIGN PATENTS Number Country Date 593,677 Germany Mar. 3, 1934