US997746A - Timer. - Google Patents

Description

G. T. BROWN.

TIMER. I APPLICATION FILED B13018, 1909.

Patented July 11, 1911 n 0 M V N I i 5 2 2 v v ATTORNEYS I GEORGE TEALL BROWN, OF NEW YORK, N. Y.,

TIMER.

Specification of Letters Patent. Patented July 11, 19] 1.

Application filed December 18, 1909. Serial No. 533,854.

To all whom it may concern: I

Be it known that I, GEORGE T. BROWN, a citizen of the United States, and a resident of the city of New York, borough of Manhattan, in the county and State of New York, have invented a new and Improved Timer,-of which the following is a full,

clear, and exact description.

This 1nvent1on relates-to certain unprovements intimers for use in controlling the closing of a plurality of electric circuits in succession, and relates more particularly to the t pe of timer commonly employed with the e ectric ignition system of multiple cylinder internal combustion engines.

The main object of my invention is to so form the timer that the length of time durstantially uniform irrespective'of the speed of the engine.

In my improved timer I close the circuit by bringing into engagement with each other, two contact members, one of which presents a helical face, and I control the ad vancement or retardation of the'spark by varyingthe point of engagement along the helical contact face in substantially the same I erably the latter. is provided-with a bracket 15-, by means of which the casing may be der to automatically control the length of manner as in my previous Patent, No. 938,208 granted October 26, 1909. In ortime of the contact, I form the face of greater width adjacent one end than adjacent thev other,-so that. as. the point of contact is moved toward one end of the face and the spark advanced to increase the speed of the engine, the contact will be made across the 'widerportion ofthe face, and this wider portion traveling athi her speed will give substantially the same length of contact as the narrower portion traveling at lower speed.

A further object of my invention is to improve the means, for advancing or retarding the time of contact.

Further objects and advantages of my improved construction will be set forth I hereinafter and the invention defined in the claims.

ing drawings, forming a part of this specification. in which similar characters of reference indicate corresponding parts in ail 'thefigures, and in which- Figure 1 is a longitudinal section through a timer constructed in accordance with my I 3, I employ a cylinder casing 10, having one end wall integral therewith and invention and in which the rotatable-contact member presents a helical face; Fig. 2. 1s a transverse section on the line 22 of Fig. 1; Fig. 3 is a development of a portion of the surface of the rotatable contact member shown in Figs. 1 and 2; and Fig. 1 is a longltudlnal section similarto Fig. 1, but

showing a form in which the plurality of gines, but it is evident that the same novel features of construction might be embodied in devices for other uses, as, for instance, in distributors and in circuit closers generallyl ing which the'contact is made, will be sub- In the specificform shown in Figs. 1 to providing a bearing 11 for a rotatable shaft 12. At the opposite end of the casing, there is provided a removable wall 13, secured in place 1 by screw threads or in any other suitable manner and adapted to. be locked against accidental loosening by a locking screw 14. fither the casing or the end wall, but prefrigidly and firmly secured to the engine base or to any other suitable support. The casing, about its periphery, is providedwith a plurahtyof openings, within whicharesupi ported aplurality of contact members-16.

These contact members are spaced-at equal distances apart and correspond in number to the number of engine cylinders. Each, contact member is insulated from the Wall of the casing in case the latter is not made.

.of insulating material, and each-".co'ntact member preferably carries at its inner end, fa spring-pressed ball which has a contact I face. The ball is capable of rotationyas it is struck by the movable contact member vhereinafter described, and is capable crin- ,slight outward mmement, so that itwill Always make the proper contact and close 1 the circuit. .I do not claim any special nev Reference is to be had to. the accompany-.5:

eltyfin the contact member per se, and "do not desire to be limited to the contact member shown, but in practice I have found. this specific contact member very efiicient in 0p" 1 eration, I v The shaft 12 isjournaledin the opposite;

- end walls of the casing, and. within the ca's-f 11b ing it carries a sleeve 17, which engages with the opposite end bearings and positively prevents any longitudinal movement of the shaft in respect to the casing. This sleeve carries a collar 18, which is free to slide lengthwise of the sleeve, but is prevented from rotating in respect thereto by a key 19. The collar is provided with an annular groove 20 adjacent one end, and within this groove is disposed a yoke 21 carried by a rod 22, extending through a hearing in the end wall 13 and parallel to the shaft 12. The rod 22 is capable of longitudinal movement into and out of the casing, and t-heyo-ke 21 is carried thereby, so as to move the collar 18 lengthwise of the casing. The collar 18 carries a second collar .23, which is held rigid in respect thereto by a set screw 24, or other suitable means. This second collar 23, upon its outer surface, has an outwardly-extending flange 25, presenting a helically-disposed contact face concentric with the shaft. This contact collar 23 and'its flange. are electrically connected with the shaft and with the engine base, while the contacts 16 are connected by separate wires to the induction coils. As the shaft 12 is rotated at a speed bearing some definite relationship to the speed of the engine, the hcli cal contact 25 is brought into engagement with the several contacts 16 in succession, so as to close the several circuits in succession. The shaft bears a. particular angular relationship to the engine shaft, so that the helical contact 25 is always in exactly the same position when the piston of any one engine passes head center, but the time at which the helical contact engages with any particular contact 16, will depend upon the lon itudinal dis osition of said helical contact. If the advanced end of the contact 25 be the portion which closes the circuit, then the cir uit will be closed early in the revolution, but if the rear or retarded end of the contact 25 be the portion which closes the circuit, then the circuit will be closed later in the revolution.

All other things being equal, the speed of the engine is largely dependent upon the time of the explosion in respect to the time of the engine piston passing the end of the compression stroke, and the more the spark is retarded the slower will he the speed of the engine.

0110 of the most important features of my present invention relates to the means whereby the du *ation of the spark or the duration of time during which the circuit is closed, will be substantially constant irrespective of the speed at which the helical contact members pass the stationary contact. In order to render this duration of time substantially constant, I make the advanced end of the helical contact of greater width than the rearward end, as is illustrated particularly in the development in Fig. 3. If the rearward end of the helical contact acts to close the circuit, the engine will be going at a slow rate of speed, and there will be a certain definite duration of contact. If the advanced end of the helical contact serve to close the circuit, the engine will ordinarily be traveling at a much higher speed, and the duration of contact due to the greater width at the advanced end will be substantially the same as before. Thus, the longitudinal movement of the rod 22 operates to advance or retard the spark, and this advancement or retardation serves to increase or decrease the speed of the engine. The variation in the speed of the engine varies the speed of rotation of the helical contact member, so that under substantially all conditions, the duration of contact will be the same.

It is not at all essential that the helical contact member be the one that rotates, or that the helical contact member be the one which is moved longitudinally to advance or retard the time of circuit closing. in the form shown in Fig. 4, certain reversals of parts are shown. In this form, the casing 10 is similar to the casing above referred to, except that it is formed entirely of insulating material. To the inner surface of this casing, there are secured a plurality of contact members 16, which present helicallydisposed surfaces, and which are connected to separate binding posts 26 extending out through the casing wall. Within the casing,

the sleeve 17 carries a collar 2i ca )ablc of longitudinal movement but held from rotation in respect to the sleeve. This collar is adapted to be moved longitudinally by a rod 22, the same as the form first described.

The collar 23 has a radially-disposed socket -tact members. The result produced is sub stantially the same as that obtained by the use of the form shown in l igs. 1, 3 and 3.

If it is not desired to operate the timer, for instance when a second or auxiliary ignition systen'i is employed, l. may move the helical contactmcmbcr of the form shown in Fig. 1, to one extreme position, so that no portion of it will engage with the contacts 16. This will permit the shaft t rotate freely without wear on any of the contacts, and without any material retarding effect. I

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A timer for internal combustion engines, comprising a casing adapted to be rigidly secured in positionl and havinge peripheral Wall and end Walls, a rotatable shaft extending through one of said end Walls into said casing and supported by the latter, a collar mounted on said shaft Within said casing and non-rotatable in respect to said shaft and movable longitudinally of the casing,-means for shifting said collar, a con 4 tagt carried by said casing and a contact carried by said collar, one of said contacts presenting a helical face, one end of whlch is of greater Width than the other end.

2. A timer for internal combustion-engines, comprising a casing adapted to be rigidly secured in position and having a peripheral wall and end Walls, a rotatable shaft extending through one of said end Walls into'the casing and supported by said end Walls, a collar mounted on said shaft Within the casing and non-rotatable in respect to said shaft and movable longitudinally of the casing, a rod extending through one of said end Walls adjacent said shaft and substantially parallel to the latter and having its inner end provided With a yoke in engagement with said collar, a plurality of contacts carried by saidcasing, and a contact carried .by said collar, one of said contacts presenting a helical face, one end of which is of greater Width than'the other.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

GEORGE TEALL BROWVN. VVitnessesi CLAIR V. FAIRBANK, PHILIP-D. RoLLHAUs.

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