US2063251A - Starting device - Google Patents

Description

DCC. 8, S, HRTZ ET AL STARTING DEVICE Filed Oct. 3l, 1935y y" `lll l 2 h *"QmvEN-vons Sansbs vHertz Magsxjce Plerre Berger ATTORNEYS Patented Dec. 8, 1936 STARTING DEVICE' StanislaskHertz and Maurice Pierre Berger, y Paris, France Application October 31, 1933, Serial No. 696,108 In Belgium November 14, 1932 a claims. (c1. 12s-'179) The invention relates to a starting device-for internal combustion engines, more particularly to the kind of device provided with a fluid control.

The chief object of the invention is to construct a starting device which shall be more efiicient than those at present in use.

In the selected embodiment of the invention illustrated in the accompanying drawing:

Figs. 1-3 show the starting device respectively in elevation, with certain parts in section, in sectionalong 2-2 in Fig. l with certain portions removed, and in section analogous to that of Fig. 2 but showing certain parts not visible in this latter figure.

Figs. 4 and 5 show, separately, in schematicy elevation and in section along 5--5 Fig. 4, certain constituent parts of the device.

The device comprises essentially at least one toothed rack b in engagement with a pinion c 2O adapted on being displaced axially at the moment of starting to communicate its rotation to the shaft a through the intermediary of a suitable coupling, the construction being such that starting is effected by communicating a longitudinal translatory movement to the toothed rack by any suitable source of energy. Such source of energy if desired may comprise either kinematic means connecting the said rack to an auxiliary motor, for example an electric motor or an inertia starter comprising a fly wheel; or by resilient means such as springs adapted to be tensioned or compressed during the period preceding starting and to be liberated when it is desired to start the engine; or by electric means such as an electromagnet moving an armature coupled to the rack; or preferably as envisaged below by a fluid under pressure or reduced pressure, for example by compressed air or by a gas liberated from an explosive cartridge or by a cartridge of liquefied gas. The toothed rack b and the pinion c are arranged in any convenient manner; the axis o of the pinion c is arranged in prolongation of the axis of the engine shaft a whereby the coupling can be directly effected by means of claws d1, d2 carried respectively by the said pinion and the said shaft, which claws are preferably in the form of inclined teeth so that the engagement can only takel place in one direction. However, in the case where the axis o should be arranged in a different manner intermediate engaging devices could also be provided between the pinion and the said shaft.

Preferably two toothed racks arranged symmetrically with respect to the axis o are employed mounted inside cylinders e, each of them being carried by a tubular member g which constitutes the rod 'of a piston h on which compressed air can operate.

The movement of each rack is effected against -the action of elastic means such as a spring i 5 arranged in the interior of the tube g which is adapted to restore the rack during its return motion. This motion could also be effected by the action of suction, or by pressure applied to the other face of the piston. If also it is found de- 10 sirable for starting to subject the rack to several successive alternate movements, this can easily be done by suitable automatic distribution of the compressed air.-

As regards the means causing the displacement 15 of the pinion c along its axis so that it engages with the claws d1, d2, these may be constituted either by an appropriate mechanical control or by means of compressed air operating on an auxiliary piston transmitting a translatory movement 20 to the pinion C along its axis or by such a construction that the rotation of the pinion c in the direction for starting gives rise to a force tending to displace the said pinion, carried by a fixed shaft y', towards the shaft a to be driven. In this 2- latter arrangement the rack and the pinion are provided with rectilinear teeth and the pinion associated with means such that the rotation communicated to it by the rack on movement of the latter tends to displace it along the axis i and 30 towards the shaft a with a helical movement. These means may be of any suitable kind, for example, a ball moving in a helical groove on the shaft 5i.

The preferred means causing the displacement of the pinion are represented in the drawing. The rack is provided with oblique teeth and the pinion with a corresponding helical set of teeth, these teeth being cut in such .a direction that the axial reaction to which they give rise when the rack is displaced inthe direction of the ar-` row f1 at the beginning of its motion tends to displace the pinion towards the shaft a in the direction of the arrow f2.

It is advisable, particularly in the case of start- 45 ing devices for vehicle or aircraft motora-to provide means such that during the operation of the motor the pinion is prevented from being displaced towards the shaft a under the action of accelerations communicated to the said vehicle 50,

or aircraft in order to prevent the occurrence of shocks, wear or disagreeable noises.

The said means consist in providing on the shaft :i one or more grooves or portions of helical grooves k, whose pitch is in the opposite direc- '55 tion to that of the set of teeth on the pinion c, these grooves coacting with at leastone roller l carried by the pinion c. The arrangement described is such that if the toothed rack isrstationary during the operation of the motor and the said roller rests in its groove, the reaction occurring in the direction of the arrow f3, which tends to separate it from the latter, occurs more or less perpendicularly to the said groove, the direction of'this reaction following th'e resultant of the movement of translation which tends to be impressed on the pinion in the direction of the arrow' j and on the movement of rotation caused by the said movement of translation-in the direction of the arrow f4, the said pinion xing itself rmly on the rack which remains stationary.

For this purpose, the helix of the grooves is arranged orthogonally with respect tothe helix of the teeth of the pinion c. v

The shaft 1' could also be made displaceable with the pinion c, in which case the rollers l are carried by the fixed housing of the starter. These rollers could also be carried by the shaft j and the grooves provided on portions of the pinion or of the housing. I

It will also. be apparent that these rollers and the grooves contribute to facilitate at the commencement of the starting the `displacement of the pinion towards the shaft a as will be ex-y plained below.

With the above construction, there is obtained a mechanism whose operation will be clearly seen from the above and which can be summarized'as follows.

To start the motor the compressed air is admitted to the'piston of the toothed racks which are thus urged in the direction of the arrow f1 causing rotation of the pinion c.

The latter owing to the axial force due to the helical teeth, is displaced towards the shaft a in the direction of the arrow f and the claws d1, d begin to engage. This axial displacement of the pinion is then considerably facilitated by the rollers l which moving in the grooves k give lrise to an axial force adding itself to that due to the teeth. As soon as the claws commence to engage. the rollers leave their grooves and roll on the smooth portion of the end of the shaft j. At this instant the resistance to rotation acting on the pinion c as a result of the driving of the shaft a increases the axial thrust due to the' teeth V,and the claws become completely engaged.

'I'he motor is thus started in this manner; as soon as the speed of the shaft a becomes greater than that of the pinion c the latter owing to a reaction due to the teeth in a direction opposite to that referred to above tends to be retracted in a direction opposite to the arrow f2, the coupling which is a section along a plane transverse to that in which the rollers move at the end of the return movement of the pinion, it will be seen that the path which they have to follow on the shaft 1 is almost a circular one.

Finally with the toothed racks brought to rest,

the rollers tend to fall into the grooves and it has been seen above that in this position the said rollers tend to prevent the pinion c from being displaced towards the shaft a, as long as the toothed racks are not actuated again in the direction of the arrow f1.

Starting can also be effected manually bymeans for example of a handle positioned on a sleeve m arranged inside the shaft i which is hollowed out and provided at its free extremity opposite the shaft'a with claws n adapted by a displacement of the said sleeve against the action of a spring p to engage with the corresponding portions. of the claws d2 which are prolonged for this purpose near to the axis of the shaft a.

While a selected embodiment of the invention has been described and illustrated, it is to be understood that it is capable of variation and. modiflcation and it is not desired to limit the invention to the precise details set forth but to embrace such changes and alterations as fall within the spirit and scope of the following claims.

We claim:-

1. A starter for internal combustion engines, comprising a shaft connected to the engine, a movable member, means engageable by longitudinal movement of said movable member to couple said movable member to said shaft, a gear having inclined teeth secured on said movable member, and means to turn said movable member and simultaneously to move the same in a direction to engage said coupling-means comprising a pair of reciprocating bars having inclined teeth engaging the teeth of said gear at diametrically opposed points thereof, and uid operated means to move said bars in .opposite directions, said movable member being hollow, and manually operable means extending through said movable member engageable with said shaft to turn the same.

2. A starter for internal combustion engines, comprising a shaft connected to the engine, a movable member, means engageable by longitu- -dinal movement of said movable member to couple said movable member to said shaft, a gear having inclined teeth secured on said movable member, and means to tum said movable member and simultaneously to'move the same in a direction to engage said coupling means comprising a pair of reciprocating bars having inclined teeth engaging the teeth of said gear at diametrically opposed points thereof, means to. move said bars in opposite directions, a supporting member extendingy within said movable member to support the same, and means to support said supporting member on the side of saidgear remote from the shaft only.

3. A starter for internal combustionengines, comprising a shaft connected to the engine, a movable member, means engageable by longitudinal movement of. said movable member to couple lsaid movable member to said shaft.- a gear having inclined teeth secured on said movable member, and means to ,turn said movable member and simultaneously to move the same in a direction to engage said coupling means comprising a pair of reciprocating bars having inclined teeth engaging the teeth of said gear at diametrically op- 7s 'posed points thereof, means to move said bars in opposite directions, a supporting member extending Within said movable member to support the same, and means to support said supporting member on the side of said gear remote from the shaft only, said supporting member being hollow,

and manually operable means extending through STANISLAS HER'IZ. MAURICE PIERRE BERGER.

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