US1295777A - Electric-circuit closer. - Google Patents

Description

E. M. McGRATH.

ELECTRIC cmc un CLOSER. APPLICATION FILED JAN. 8. I9I8.

Patented Feb. 25, 1919.

2 SHEETSSHEET l- E. M. McGRATI'L' I ELECTRIC CIRCUIT CLOSER. APPLICATION FILED JAN. 8. I918.

Patented Feb. 25, 1919.

2 SHEETS-SHEET 2 Q /4 K I l UNITED STATES PATENT OFFICE.

EARL M. MCGRATH, or HELENA,I.MONTANA.

ELECTRIC-CIRCUIIT CLO'SER.

To all whom it may concern:

Be it known that I, EARL .MORRIS MCGRATH, a citizen of the United States, residing at Helena, in the county of Lewis and Clark and State of Montana, have invented certain new and useful Improvements in Electric-.

ments in electric, circuit closers where it is desired to shift anelectric circuit so that it may be caused to passthrough a series'of electrically-operated devices, such as Incandescent lamps, so that the current may flow through said devices either in series,,or in parallel, or in multiple groups, as may be desired.

My invention is especially intended to provide a circuit closer for use in controlling the headlights of automobiles, such as is described in my application filed November -30, 1917, Serial No. 204.614.

In order that the invention maybe more fully understood, it will be convenient to refer briefly to such a system to which said invention isespecially adapted, and then to describe in detail the construction of the parts constituting the present invention.

Reference is had to the accompanying drawings, in which similar reference symbols indicate similar parts throughout the several views, and in which Figure. 1 is a diagram showing the system with the circuit closer shown diagrammatically and in the position for causing the current to flow through the lamps in parallel.

Fig. 2 shows the other position of the circuit closer, in which the current iscaused to flow through the lamps in series.

Fig. 3 is a detail perspective view showin the casing'containin the circuit closer, an the plunger mounte therein.

Fig. 4 shows a central vertical section through the casing shown in Fig. 3, parts be ing shown in elevation, and the plunger being in the position for transmitting the current through the lamps in series.

Fig. 5 is a similar view, but showing the plunger in the positionfor transmitting the current through the lamps in multiple.

Fig. 6 shows a section along the line 66 of Fig. 4, and looking in the direction of the arrows,

Specification of Letters Patent.

Application filed January 8, 1918. Serial N 0. 210,857.

Patented Feb.

Fig. 7 is a plan view of the insulating plug closing one end of the circuit closer casing.

Fig. 8 shows a section along the line 88 of Fig. 7, and looking in the direction of the arrows; and

Fig. 9 is a detail perspective view showin the circuit closer connections as detachedfrom the casing.

Referring first to the diagram shown in Figs. 1 and 2, Arepresents a magneto generator; B represents the headlight switch; C and C represent the headlights; D represents the auxiliary switch or electric circuit closer; and G represents the ground to which the various which, in the caseof an automobile, is the -metallic framework of the machine.

The current flows from the generator A through the terminal 1 to. the headlight swltch B, which is shown in the open position in Fig.1; but which, when closed, willtransmit the current to the conductor 2, which has two branches 3 and 3.

Q The current flows, when the parts are in the position shown in Fig. 1, in parallel through the lamps C as follows :from the conductor 2 through the conductor 3 and thelamp C and the conductor 4 to the terminal 5, brush 6, the terminal 7 and the conductor 8 to ground.

The current flows through the lamp C as follows: from the conductor 2 through. the conductor 3 to the terminal 9, the brush 10, the terminal 11, the conductor 12, the lamp C and the conductor 13 to ground.

When the parts are in the position shown in Fig. 2 the current flows from the conductor4 to the terminal 5, as before, and passes to the brush 6, but instead of going through the terminal 7, as shown in Fig. 1, the current passes from the brush 6 through the conducting bar 14 to the brush l0 and thence to. the terminal 11, whence it flows terminals are connected,

as heretofore- In the position shown in Fig. 2, the terminals 7 and 9 are cut out of circuit, as are also the conductors 3 and'8, so that the current in this case will pass through the lamps in series. The brushes 6 and 10 are insulated from each other, as shown at 15.

The circuit closing and breaking arrangement, shown diagrammatically in Figs. 1 and 2, is illustrated in detail in Figs. 3 to 9, in which 20 represents a shell preferably cylindrical in form, having a flange or ring 21 secured to the upper end thereof. Fixed in the lower end of this shell is the insulating plug 22, which is cut out at the center, as at 23, and is provided with an'upwardlyprojecting post 24 and a shorter upwardlyprojecting post 25, each as at 26 and 25 to facilitate the securing ofthe terminal wires 5, 7 9 and 11, which are preferably made in the form of a hairpin, one end of which passes through the outer grooves 26, and the other end passes through the inner grooves 26 and the perforations 27 in said plug, and the ends of the wire forming the terminals are then twisted together and are connected to the conductors 4, 8, 3 and 12, respectively.

The shorter post 25 is recessed, as at 25, see Fig. 8, and across the recessed portion is secured the conducting bar 14 shown in Figs. 4 and 5.

Mounted in the upper end of the cylindrical casing 20 is a cylindrical cap 30, in which is mounted the insulating piece 15, to which the brushes 6 and 10 are secured. These brushes are preferably in the form of a a hairpin, having outwardly curved contact ends as shown most clearly in Figs. 5 and 6. This cylindrical cap is normally held in the raised positionshown in Fig. 4 by means of the spring 31, which engages an arm 32 secured to, but preferably integral, with the said cap, the upper end of said spring epslot 34 in the cap 30.

When the cap 30 1s in the raised position shown in Fig. 4, the brushes 6 and 10 are in the position shown in Fig. 2, and connect the lamps inseries; but when the cap 30 is pressed down to the position shown in Fig. 5, the brushes 6 and 10 are in the position shown in Fig. 1, and While still remaining in contact with the terminals 5 and 11 have moved out of contact with the bar 14 and into contact with the terminals 7 an Thus it will be seen that these brushes always remain in contact with the terminals 5 and 11, but when in the raised position are connected by the bar 14, and in the lowered position are out of contact with the bar 14 but in contact with the terminals 7 and 9 on the short post 25 of the insulating plugi122.

T e upper end of the cylinder 30 is closed by a cap piece 35 which serves as a hearing or push button for the operator, and also by closing the upper end of the cylinder 3) constitutes a neumatic dash-pot arrangement by imprisoning the air in the circuit closer and tends to prevent any objectionable click when the cap 30 is pressed down. This action of the imprisoned air is also supple,

mented by the resiliency of the spring 31.

The brushes 6 and 10 are made of springs of suflicient stiffness and resiliency to form of which is grooved,

, tube being rovided with always-a perfect electrical connection with the corresponding contact members, in spite of the jolts and vibrations to which the car is necessarily subjected in its normal use. Moreover, this stiffness of the spring brushes serves as a friction brake against the action of the spring 31, and thus prevents the sudden expulsion with resultant click of the plunger 30 when released from pressure bythe operator.

Obviously the spring 31 should also be strong enough to returnthe plunger to the initial position against such friction, when the plunger is released.

. The operation of the device will be fully understood by reference to Figs. 1 and 2 of the drawings,

parallel or in series, as the case may be. It will be seen that the plunger or cap is which show the plunger or cap in the lowered and raised positions, re-. spectively, for connecting-the lamps either always automatically returned to the initial construction and in the combination and arrangement of parts which could be used Without departing from the spirit of my invention; and I do not mean to limit the invention to such details unless particularly pointed out in the claims.

Having thus described my invention, what I claim and desire to secure by ent of the United States is 1'. In an electric circuit closer, the combination with two telescopic tubes, the inner a cap, of an insulating plug mounted in the outer tube opposite said cap and carrying two opposed pairs of contacts, onepair of contacts being shorter than the opposite pair, bar spaced away from said shorter pair of contacts and opposite to the upper end of the longer fpair of contacts, an isulating block carried by said inner tube, of a hair in connected to said insulating block and aving their free ends on one side adapted to continuously engage the longer pair of contacts carried by said insulating plug, and on their opposite side adapted to engage either said conducting bar, or said shorter contacts, substantially as described.

2. In an electric circuit closer, the combination with two telescopic tubes, the inner tube being provided with a cap, of an insulating plug mounted in the outer tube 0p posite said cap and carrying two opposed pairs of contacts, one pair of contacts being shorter than the opposite pair, with a conducting bar spaced away from said shorter pair of contacts, an insulating block carried by said inner tube, and

a pair of resilient Letters Patwith a conducting 1 and a pair of resilient brushes each substantially in the form of contacts hairpin connected to said insulating block and having their free ends on'one side adapted to continuously engage the longer air carried by said insulating p ug, and on their opposite side adapted to engage either said conducting bar, or said shorter contacts, with a spring normally the raised position, substantially as described.

3. In an electric circuit closer, the combination with two telescopic tubes, the inner tube being provided with a cap, of an insu lating plug mounted inlthe outer tube opposite said cap and carrying two opposed pairs of contacts, one pair of contacts being shorter than the opposite pair, with a con-' ducting bar spaced away from saidshorter pair of contacts and end of the longer pair of-contacts, an insulating block carried by said inner tube, a pair of'resilient brushes connected. to said insulating block and having their 'free ends v on one side adapted to' continuously engage the longer pair side to engage either said shorter contacts, the inner tube being provided with a slot,

adapted to continuously enga pair of contacts carried by t of contacts can'ied'by the said insulating plug, and on their opposite said conducting bar or a pin projecting from the outer tube through said slot, and a spring having one end secured to said pin and the other end connected to stantially as described.

4. In an electric circuitcloser, the combisaid inner tube, sub- 7 nation with two telescopic tubes, the inner 'latingplug mounted in the outer tube oppo-' site said cap and carrying two opposed pairs of contacts, one

tube being provided with a cap, of an insupair of contacts being shorter than the opposite pair, with a conducting bar spaced away from said shorter pair of contacts and opposite to the upper end of the longer pair of contacts, an insulating block carried by said inner tube, a pair of resilient brushes each substantially in the form of a hairpin connected to said insulating block and having their free ends on one side e the'longer opposite to the upperscribed. v v i I v In; an electric circuit closer, 'the combisite said cap and the distended position,

c said inswengage either said conductin bar or said shorter contacts, the inner tu being provided with a slot, a pin projecting from the outer tube through said slot, and a spring having one end secured to said pin and the other end connected to said inner tube, substantially as described.

' 5. In an electric circuit closer, the combination with two telescopic tubes, the inner tube being provided with a cap, of an insulating plug mounted in the outer tube opposite said cap and closingthe same, the two cylinders closedat opposite ends respectively forming a pneumatic dash-pot, contacts carried by said plug, ried by said inner tube and engaging said contacts, the inner tube being provided with a slot, a pin projecting from the outer tube through said slot, and a spring having one end's'ecuredto said pin and the other end connected to said inner tube and adapted to automatically restore said inner tube to the distended position, substantially as denation with two telescopic tubes, the inner tube being provided with a cap, of an insulating plug mounted in the outer tube oppothe outer walls thereof, and with perforationsnear the center thereof, metal contact strips in the form of wires laid in saidouter grooves and passing through said perforations, and having the free ends of each wire twisted together, resilient brushes carried vby said inner tube positioned to engage the contact strips carried by said insulating plug, the inner tube being provided with a slot, a pin projecting from the outer tube through said slot, and a spring having one [end secured to said' pin and the other end connected 'to said inner tube and adapted togautomatically restore said inner tube to substantially as de scribed.

In testimony whereof, I aflix my signature.

EARL M. MoGRATH.

brushes carprovided with grooves in

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