US926066A - Multiple-contact timer. - Google Patents

Description

H S. LINCOLN.

MULTIPLE CONTACT TIMER.

APPLICATION FILED MAY 5,1908.

PatentedJune 22, W09.

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UNITED STATES PeTENT OFFICE.

EDWIN S. LINCOLN, OF BROO-KLINE, MASSACHUSETTS, ASSIGNOR T0 ELECTRIC GOODS MAN- UFACTURING COMPANY, 'OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

MULTIPLE-CQNTACT TIMER.

Specification of Letters Patent.

Application filed May 5, 1908.

Patented June 22, 1909.

Serial'No. 431,024.

To all whom it may concern:

Be it known that I, EDWIN S. LINCOLN, citizen of the United States, residing at Brookline, in the county of Norfolk and State .of Massachusetts, have invented certain new and useful Improvements in Multiple-Com tact Timers, of which the following is a specification'.

My invention relates to timers adapted to distribute electrical energy to the ignition systems of the cylinders of explosive engines, so as to energize said systems and to explode the gaseous charge in the engine or motor cylinders at the desired time.

As is well known, timers employed for the purpose above mentioned, consist essentially of a rotating member carrying a moving contact adapted to successively engage a series of stationary contacts, the engagement of the moving cont-act with any stationary contact serving to complete an electrical circuit by which the ignition system of the cylinder controlled by that contact is energized.

Ordinarily it is the practice to provide a series of stationary contacts corresponding in number to that of the cylinders of the engine controlled thereby, and mounted at angularly equal intervals on the circumference of a stationary member axially concentric with the rotating member. Thus a four cylinder timer has four stationary contacts spaced ninety degrees apart, or a six cylinder timer has six contacts spaced sixty degrees apart,

The rotating member, furthermore, has been driven so as to make one revolution for each double revolution of the motor controlled by it, if a four cycle motor, or for each single revolution of a two cycle motor.

The construction above outlined has led to the result, which is especially manifest in the caseof high speed two cycle engines, that the rotary member of the timer revolves with great rapidity, and in consequence not only is there excessive wear on the timer parts, but the period of engagement between the contact carried by the rotating member and the stationary contacts is of exceedingly brief duration. The said engagement is furthermore, often imperfect, owing to the rapidity of the engagement of the contacting contacts, and to the small area of the surthus reducing the wear on the rotating parts of the timer, and with the further result of securing a largely increased period of engagement between the moving and the stationary contacts. -At the same time I aim to make provision'whereby the surface of engagement between the moving and the stationary contacts is increased to theoretically double that possible in a similar type of timer not embodying my invention. The result is a timer of greatly increased durability and efficiency as compared with those hitherto in use.

In the drawings is shown one embodiment of my invention, Figure 1 being a side view of the same, partly in section, and Fig. 2 a plan View of the same, showingcthe timer wall partly in section on the plane Bf-Z, of Fig. 1.

Referring to the drawings, 1 shows the timer base, means being provided, as screws 2 engaging curved slots 3, by which the base may be adjust-ably secured to the motor in the desired position of angular adjustment. To the base is secured the wall of the case, in dicated by the numeral 4, the same preferably being in the form of an annular piece of insulating material, as hard rubber or the like, andliaving the stationary contacts 5, 5 6, 6, 7, 7, and 8, 8, mounted therein. Such contacts may be providedwith means whereby they may be individually or collectively adjustable, radially, or otherwise, but such means forms no part of my invention and thereforeis not shown in the drawings. A cover 9 is adapted to it over the case, being secured to the topof the walld by screws or other suitable devices.

The timer shaft which may be geared, or otherwise positively driven from the motor,

by means not shown in the figures, is indior electrically insulated therefrom, as well as.

from the timer base, as by the use of the insulating bushing 12, and the washer 13. On

as the ,rotating member 11 revolves the contact rollers 17 roll over the internal circumferential surface of the'wall 4.

Mounted in the wall 4,,so as tolie in the ath of the rollers 17, are a series of contact locks 5, 5 6, 6*, 7, 7*", and 8, 8 which in number are a multiple of the number of cylinders in the motor controlled thereby, being preferably twice the number of the cylinders, where th'e rotating member carries two contact .wheels, three times the number there are three contact wheels, and so on.

The construction of a four cylinder timer having, as shown in the drawings, two con-' tact rollers, and eight contacts, will alone be described in illustration of my invention, the construction of timers to suit other situations being identical in principle, and requiring only modification in their mechanical details. In the timer shown in the drawings the stationary contact blocks'are spaced angularly equidistant, on the wall 4 of the timer case, and they are arranged to form four airs of diametrically o osite contacts P l P whose members are electrica ly connected by wires or other appropriate connections. 'Thus conductor 21;.electrically unites contacts 5 and 5 22 connects 6 and 6 23, 7 and 7; and 24, 8 and 8 One contact of each pair of contact blocks, as for example 5, 6, 7, and 8, are provided with binding screws or the like, bywhich may be secured wires 25, 26, 27, and 28, which .lead to one of the terminals of the ignition systems of the various cylinders of the motor controlled by the timer. The other terminals of the ignition systems of the said cylinders, maybranch from a single wire 29 leading to binding post 16 on the cover 9 of the timer, and so be in electrical connection with the rollers 17 through brush 15 and ring 14, or'said terminals may be in electric connection with said rollers 17 by grounding through the motor frame, in usual and well known manner, the rotating member 11 in such case being mounted directly upon the shaft 10 without the use of the insulatingbushing 12. Said rollers 17 are in electrical connection with each other through the rotating member by which they are carried. When, therefore, the contact rollers 17 are in any position of engagement with the stationary contacts, as for example, with the pair of interconnected contacts 5 and 5*, the circuit leading to the ignition system will be closed both through. the engagement of one contact roller with contact block 5, and also through the other roller and contact 5*. Thus an area of contacting surfaces is secured which is theoretically double in amount that secured in a timer of 'usual construction, resulting in a largely increased efficiency for the ignition system. Furthermore the symmetrical formation of the rotating member, incident to the use of a plurality of contact rollers, or the like, secures a more perfect balance of the rotating member, and leads to a smoother and more even running of the same. Again it will be observed that, if the rotating members revolve clockwise, the contact rollers 17 will simultaneously engage contacts 6 and 6 after one eighth of a revolution of the rotating member; with contacts 7 and 7*, after one quarter of a revolution; with contacts 8 and 8, after three eighths of a revolution; and again coming into contact with contacts 5 and 5 after one half a revolution of the rotating member has been completed. Thuslthe electrical energization of the ignition systems of all the engine or motor cylinders will be completed during one half of a revolution of the timer, and in consequence it is necessary that the timer have a rate of revolution but half that of a timer having but a single set of engaging contacts.

The result of the slower rate of rotation of my timer is a lessened amount of wear, while by reason of the relatively slower speed with which the moving and stationary contacts engage, a more perfect contact is secured. These advantages, combined with the fact that the contacting surfaces through which the ignition circuit is com leted, are sub stantially double in area t ose of a timer having but one set of contacting surfaces pro duce a timer of largely increased mechanical durability and electrical efficiency over those hitherto. employed.

Having described my invention what I claim and desire to secure by Letters Patent is:

1. In a timer ada ted to control the ignition system of mu ti-eylindered explosive engines, or the like, two members having a ca acity for rotation with respect to each ot er, one of said members having a plurality of contacts in electrical engagement with one terminal of the ignition system of each cylinder of said engine, and the second member embodying a plurality .of contacts arranged in electrically'insulated sets, the number of such sets corresponding to the number of the engine cylinders control ed b the timer, and each set comprising 'a lura ity of contacts individually electlica y connected to each other and collectively connected electrically to the unengaged terminal of the ignition system of one of the cylinders of said engine, the contacts 01' the first member being adapted to simultaneously engage in succession with the contacts comprised in each of the said sets as one member revolves 'with reference to the other member, substantially as described.

2. In a timer adapted to control the ignition system of a multi-cylindered explosive engine, or the like, in combination, a rotating member having a plurality of contacts, collectively in electrical engagement with one terminal of the ignition system of each engine cylinder, and a stationary member embodying a plurality of electrically insulated stationary contacts arranged in electrically insulated sets, the number of such sets corresponding to the number of the engine cylinders controlled by the timer; each set comprising a plurality of' stationary contacts, individually in electrical communication with each other, and collectively in electrical communication with the unenga ed terminal of the ignition system of one of t 1e cylinders of said engine, the contacts of the rotating member being adapted to simultaneously engage in succession with a plurality of the stationary contacts in each set as the rotating member revolves.

In testimony whereof I affix my signature in presence of two Witnesses.

EDWIN S. LINCOLN.

Witnesses NATHAN B. DAY, WILLIAM A. COPELAND.

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