US1254923A

US1254923A - Electric starter for internal-combustion engines.

Info

Publication number: US1254923A
Application number: US18164317A
Authority: US
Inventors: Albert Henry Midgley
Original assignee: CA Vandervell and Co Ltd
Current assignee: CA Vandervell and Co Ltd
Priority date: 1917-07-19
Filing date: 1917-07-19
Publication date: 1918-01-29
Anticipated expiration: 1935-01-29

Description

A. H. MIDG-LEY. ELECTRIC STARTER FQR INTERNAL COMBUSTION ENGINES. APPLICATION FILED JULY 19.19l1.

1,254,923. Patefited Jan. 29,1918.

UNITED STATES PATENT OFFICE.

ALBERT HENRY MInGLEY, or ACTON VALE, ENGLAND, ASSIGNOR or or go 0. A. VANDERVELL AND COMPANY LIMITED, or ACTON VALE. ENGLAND.

i ELECTRIC STARTER FOB-.INTERNAL-COMBUSTION ENGINES,

72) all rirhom, it may concern:

Be it. known that 1". Aunzu'r l'Il-INl-Y Mioc- Lm', a subjcct ofthc King of (ircat Brit-- ain and Ireland. and residing at \Varplc \Vay. Acton Yalv, in thc count of Middlescx. England, haw inrcntcd rvrtain now and useful Improvements in and Relating to Electric Starters for Tntcrnal Combustion Engincsfo'f which the follrnvim; is a specification.

Tll'is invention relates to an improved clcctric starter internal combustion cugincs of the kin-l wherein the initial engagvmcnt' of the goal members is effected by a longitmlinal .mo'yclncnt of tho armature shaft; under magnetic action and the completion of thc' cngagcm'cnt by means of-n screw or helical conncction lictwccn the longitudinallr morahlv armature shaft and the memberof tho g car carried by the latter, such as dcscribcd in British patent specification N 242953- of 1914. V

In stinrtcrs of the kind abore'rcferrml to, the longitudinal movement of the armature shaft is substantially reduced as compared I with the longitudinal movement of the shaft in starters which are not providcd .with a screw or l clica'l dcvice andwhcrcin the one nicmbcr of'tlic gear is fixcdto said shaft', and one object of t'lie'prcsent. invention is to further rcd'ucc the longitudinal movementof thefshafti; another object bcing to improv t-he initial stage of operation of the sta rt'ing device;

3 \Vifth" these objects in view the invention consists in causing a friction disk or equivalent-.mcmber uscd in' conjunction with the pinion which is connected withithe longitudinally movable armature shaftthrough the screw mhclical device to be brought intogfrlctional' contact with the fly-wheel of thccngine or other lfltill'y' or stationarylnenibcr undcrslow rotation ofj thcclectric mot oi" and? bj awrylongitudinal. movement; of Its armnti n'o'slmft,prior to the 1 initial engagement of th'c'toothcdmcml'icrs ofrthc gear, which latter cngngem'ent is subsequent-1y cifl'ccteda-ndl'complcted by the screw or hehcal device ina known manner.

may 'citlierbe attached to the pinion-or'ar- The friction disk or equivalent: member ranqedto rotate'thcrcwith. while being ca: pab le oflmoving longitudinally relatively thereto; as has already" been proposd'" in electric'starters wherein an ordinary motor is employed. thc shaft. of which is connected with tho pinion by means of a screw or helical device but is not longitudinally movable as in the arrangement according to the pros out invcnt-ion and whcrcin the friction do vicc comes into operation before the initial cngagcmentof the gear mcmbvrs in order to assist the cti'ect of the inertia of the. pinion and thereby insure its operation and more particularly its'cngagcmcnt with the other member of thc gcar. The arrangement according to the present invention differs from thrse forms of construction which have previously been proposed in that the short, longitudina'l.inorcmcnlz of the shaft 'under slow rotation is employed for initiating the' op yuration of thestarl'cr, and not the inertia of the pinion and friction disk which is dependent upon a rapid acceleration of the clccfric motor as is the case in the known forms of construction.

Referring to the accompanying drawing which illustrates by way of example one mode of carryingtzhc invention into effect,-

a is the electric motor b its longitudinally vdisplaceahlc' armature shaft, 0 a helically thrcadcd member suitably keyed to the armature shaft, and (Z is a pinion which is mountcdin helical engagement with the helically thrcadcd member 0 and is adapted to 006pcrate with a toothed ring e provided on the f y-wheel of the engine to be started or on other rotary member connectedor cooperating therewith.

f isii friction ring mounted on a'cOVer g 9 0 which is loosely supported on the longitudinally movable nrmaturc'sha-ft b" i i-such a. manner as positively to follow'the longitudinal displacement of the latter in one or the 'othcr direction and thereby be brought into frictional cngagcment with the side of the toothed ring 0 or'other rotary' orstationary part" ofthe engine} The pinion d is pro- .vided' with a: guiding pin h-j-arra-ngd slidingly to engage with the cover g. i is a spring interposed between a stationary part 'of the electric motor and -an abutmentj on tlie'iu'mature'ishnft and arrang'cdtoact in awcll' known manner durin the inward longit udinal movement of tic shaft and for causin the outward d isplaccment thereof.

Instcad-of'mounting the friction ring f 0L a. member gf0 rming a cover for the pinion (l as has previously been prpposed'the same may otherwise be loosely-supported on the longitudinally movable shaft in such a manner that it shall follow the longitudinal displacement thereof, and the details of con struction of the starter hereinbefore described may otherwise be modified without in any way departing from the spirit of the invention.

What I claim is An electric starter for internal combustion engines comprising in combination an electric motor havin an armature shaft capable of longitudlnal displacement, a toothed gear,.one member of which is connected with the en ine to be started while the other member tiereof consists of a helically threaded pinion, a helical thread on the longitudinally displaceable armature shaft in engagement with the helically threaded pinion, and a friction device constituted by two members, one of which is sup )orted on the longitudinally displaceable sha t so as to be capable of relative rotation thereon, together with the hclically threaded pinion, and be compelled positive] to follow the longitudinal displacement o" the armature shaft, the distance between the members of the friction device being shorter than the distance between the members of the toothed gear, whereby the friction device is brought into operation during the lon 'itudinal displacement of the armature shaft and before the initial engagement of the members of the toothed gear, as set forth. In testimony whereof I have signed my name to this specification.

ALBERT HENRY MIDGLEY.