US2666331A

US2666331A - Engine turning gear

Info

Publication number: US2666331A
Application number: US325260A
Authority: US
Inventors: Hewson Robert Philip
Original assignee: Stanley Engineering Co Ltd Great Britain
Current assignee: Stanley Engineering Co Ltd Great Britain
Priority date: 1952-01-09
Filing date: 1952-12-11
Publication date: 1954-01-19
Anticipated expiration: 1971-01-19

Description

Filed Dec. 11, 1952 Jan. 19,1954- R. P. HEWSON 2,666,331

ENGINE TURNING GEAR I 2 Sheets-Sheet 1 Jan. 19, 1954 R. P. HEWSON ENGINE TURNING GEAR 2 Shets-Sheet 2 Filed Dec. 11, 1952 Wbbar?" P H WSan Patented Jan. 19, 1954 to The Stanley Engmeermg Egh'am, England Company Limited;

Applicatidn December 11, 1952, Serial No. 325,260

filaims priority application Great firitain January 9, 1952 This invention relates to engine aiming g ar and has for its main objec't to provide an impr'bved mini of turning gear for effecting the starting of an internal combustion engine.

The invention is mainly suitable for use with light engines, and is thus particularly applicable to internal combustion engines for use in invalid carriages, motor cycles, motor cars and other light vehicles.

The invention consists in a turning mechanism for starting internal combustion engines, comprising a belt drive for coupling the engine shaft with a starter device, said belt drive passing round a driving pulley adapted to move longitudinally in response to rotation by said starter device, and a driven pulley associated with said engine shaft, said driven pulley being formed in two parts, one of which is freely mounted and the other of which is keyed to the engine shaft whereby the belt drive is adapted to move from one part of said pulley to the other part in response to the longitudinal movement of said driving pulley and thereby effect the turning of the engine shaft.

According to the preferred arrangement, the part of the driven pulley which is keyed to the engine shaft forms part of the engine flywheel, and the freely mounted part of the pulley is mounted in bearings carried on the engine shaft.

The invention will be more completely understood from the following detailed description which is given in conjunction with the accompanying drawings, in which:

Figures 1 and 2 are front and fragmentary side views respectively of an internal combustion engine which is suitable for use in an invalid carriage, motor cycle, car or other light vehicle, and in which the invention is embodied.

Referring now to these drawings, the engine shown is constructed in substantially orthodox form, comprising a main supporting frame I on which is mounted a cylinder 2, a carburetor 3, a crank case 4, and an electric starter device 5 of any well known form, this starter device being secured in position in such .a way that the driven shaft 6 of the starter device is disposed substantially parallel to the engine shaft I. The driven shaft 6 of the starter device 5 extends some distance beyond the starter device casing and part of this shaft is provided with a helical thread 8 on which is mounted a V-shaped pulley 9 preferably formed of cast iron, this pulley having an internal helical thread I engaging with the helical thread 8 on the shaft so that this pulley 9 is adapted to rotate with the shaft 6 when the latter is driven by the starter but is also 6 claims. (01. 74:7)

2 adapted to slide along the shaft in respohse tc relative rotation between the shaft and thepul137 as determined by the helical thread. This pulley 9 constitutes the driving pulley of the turning gear and is adapted to be coupled to the engine shaft l by a driving belt II which passes round this pulley 9 and also round a second or driven pulley mounted on the engine -shaft. This latter pulley, however, is formed in two parts I2 and I3, and each part is of sufficient width to earl? the driving belt II which is thus free to slide from one part of the pulley to the other. One part I3 of this pulley is formed as an extension of the flywheel I4 so that it is permanently keyed to the engine shaft so as to rotate with it, but the other part I2 is freely mounted for independent rotation and is conveniently mounted in bearings I4 disposed in a ball race I5 secured by bolt I6 to an internal shaft I! screwed into the interior of the engine shaft I on which the flywheel I4 is mounted.

The driving and driven pulleys are so relatively positioned that when the engine is stationary the freely mounted part I2 of the driven pulley is disposed immediately. opposite or below the driving pulley 9 so that the belt is perfectly free to rotate. When, however, currendis applied to the starting device 5, e. g. by the pressing of a button or the closure of a switch, the sudden rotation of the shaft 6 of the starter device acting against the inertia of the aforesaid driving pulley 9 causes the latter to slide inwards along the helical thread 8, thus causing the driving belt I I to slide on to the part I3 of the driven pulley formed on the engine flywheel and thus rotate the latter. As soon as the engine starts up, however, and current is disconnected from the starter device 5, the driving pulley 6 will slide back into its original position and cause the driving belt I I to slide back on to the freely mounted part I2 of the driven pulley, thereby allowing the engine flywheel and shaft to run freely and leaving the starter gear in readiness for the next operation with the belt I I and associated pulleys stationary.

It will thus be seen that by means of this arrangement a very smooth form of starter mechanism is provided, and the customary banging which normally takes place by a pinion wheel being flung into engagement with the flywheel teeth of the engine is entirely obviated. Moreover, in view of the fact that the driving belt and 7 its associated pulleys remains stationary except when it is in actual operative movement, all un- 5 necessary wear on the driving belt is substantially eliminated.

I claim:

1. Engine turning mechanism for starting internal combustion engines, comprising a belt drive for coupling the engine shaft with a starter device, said belt drive passing round a driving pulley adapted to move longitudinally in response to rotation by said starter device, and a driven pulley associated with said engine shaft, said driven pulley being formed in two parts, one of which is freely mounted, and the other of which is keyed to the engine shaft, whereby the belt drive is adapted to move from one part of said pulley to the other part in response to the longitudinal movement of said driving pulley and thereby effect the turning of the engine shaft.

2. Engine turning mechanism for starting internal combustion engines, comprising a belt drive for coupling the engine shaft with a starter device, said belt drive passing round a driving pulley adapted to move longitudinally in response to rotation by said starter device, and one or other of two pulleys disposed adjacent one another, one of such driven pulleys being freely mounted, and the other being formed on the engine flywheel, the belt drive being free to move from one driven pulley to the other in response to the longitudinal movement of said driving pulley so as to effect the turning of the engine flywheeland shaft.

3. Engine turning mechanism according to' corresponding helical thread on the shaft of said starter device, whereby relative rotation between the shaft and the pulley effected by said starter device, brings about a longitudinal movement of the pulley with respect to the shaft.

6. Engine turning mechanism according to claim 1, wherein said driving pulley is so arranged as to be disposed substantially opposite the freely mounted part of said driven pulley when the engine is stationary, whereby the longitudinal movement of said driving pulley brought about by said. starter device causes said belt drive to move over. from the freely. mounted part of said driven pulley on to the part keyed to the engine shaft.

ROBERT PHILIP HEWSON.

References Cited in the file of this patent UNITED STATES PATENTS Number