US2353904A - Engine starter gearing for internal-combustion engines - Google Patents

Description

July18,1 944-. B NES 2,353,904

ENGINE STARTER GEARING FOR INTERNAL COMBUSTION ENGINES Filed April 21, 1945 INVENTOR. Big/Till. Jms

BY M I ATTORNEY Patented July 18, 1944 ENGINE STARTERGEARING FOR INTERNAL- COMBUSTION ENGINES Burr W. Jones, Elmira, N. Y., assignor toBendix I Aviation Corporation; South Bend, Ind., a corporation of Delaware Application April 21, 1943, Serial No. 483,954

6 Claims.

The present invention relates to starter gearing for internal combustion engines and more particularly to that type of gearing in which a motor driven pinion is shifted axial y into ongagement with an engine gear prior to energ zation of the starting motor, the pinion being arranged to overrun the starting motor when the engine starts.

In devices of this type as now commerc ally manufactured, it is usual to incorporate special provisions for enforcing proper mesh of ihe pinion in case of tooth abutment. Moreover, the forms of overrunning clutch generally used tend to generate quite severe localized stresses which necessitate a comparatively heavy and expensive structure andwhich may cause the clutch to jam and fail to release.

It is an object of the present invention to provide a novel starter gear shift which is emcient and reliable in operation and simple and economical in construction.

It is another object. to provide such a device in which a single element of elastically deformable material is used both as a mesh enforcing means for the starting pinion and as an over-' running clutch member for rotating the pinion.

It is another object to provide such a device in which jamming or sticking of the clutch is eifectively prevented.

It is another object to provide such a device in which a small portion of the elastic element is used to cushion the meshing operation. while the entire element is used to transmit torque lo thepinion to crank the engine.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation partly in section of a preferred embodiment of the invention;

Fi 2 is a similar View showing the parts in the positions assumed when a tooth of the pinion abuts against the tooth of the engine gear;

Fig. 3 is a view similar to Fig. 1 showing the parts in cranking position;

Fig. 4 is a detail of the driving and shifting barrel member partly broken away to show the clutch actuating cam means;

Fig. 5 is a detail in perspective of the yielding clutch member and Fig. 6 is a detail in perspective of the cent-el ing and supporting element for the yielding clutch member.

In Fig. 1 of the drawing, there is illustrated a power shaft l which may be the extended armature shaft of a starting motor not illustrated.

A portion 2 of the power shaft is formed with splines or key-ways on which is slidably but-nonrotatably mounted the hub 3 of a barrel memper 4. The hub 3 is formed as a grooved shirt collar and means such as a fork member 5 controlled by the operator is provided for sliding the barrel axially along the power shaft I. A

A pinion '5 is slidably journalled on the power shaft l for movement into and out of engagement with a member such as a gear 1 of an engine to be started. The pinion is arranged to telescope within the barrel 4 and a flange member 8 having a splined connection at 9 with the teeth of the pinion, is retained in the end of the barrel by means of an annular plate member ll keyed to the barrel at l2 and retained by a lock ring IS. A stop ring M is rigidly fixed to the end of the pinion 6 and limits the projection of the pinion from the barrel by abutting against the interior of the flange member 8.

Means forming an overrunning clutch connection between the barrel and the flange member 8 is provided in the form of an annular block ill of elastically deformable material such as rubber mounted in the 'barrel member adjacent the flange member. The inner end of the barrel is provided with cam members it (Fig. 4) and the adjacent surface of the rubber block l5 has pref erably molded thereon a driven cam member I! arranged to cooperate with the cams it to compress said block against the flange member 3 when torque is transmitted from the barrel to the block.

According to the present invention a portion of the yielding clutch member E5 is used to normally maintain the pinion '6 in extended position with respect to the barrel 4 as illustrated in Fig. 1 but to yield and permit the pinion to telescope into the barrel in case of tooth abutment with the engine gear as shown in Fig. 2. This is accomplished by extending a portion of the member I5 radially inward as shown at l8 and forming a groove 59 back of said shoulder so as to make that portion of the block comparatively elastic. The portion 18 of the rubber block is arranged to bear against the stop ring [4 on the pinion and thus normally hold the ring against the inner surface of the flange member 8.

In order to reduce the friction between the periphery of the clutch block l5 and the inner surface of the barrel 4, it is preferable to provide a sleeve 2! surrounding said block to prevent its radial expansion and provide a free bearing in the barrel. Means for centering the block l 5 and providing a bearing therefor on the power shaft may also be provided as illustrated in Fig. 6 wherein is shown a bearing ring 22 journalled on the splined portion 2 of the power shaft and supporting the interior of the block and the driven cam member II. The member 22 may, if desired be provided with radially extending projections 23' which cooperate with the 'driven cam member I! to lock the elements for rotation in unison.

In operation, starting with the parts in the positions illustrated in Fig. 1, actuation of the-shift fork by the operator to move the barrel along the power shaft causes the pinion 6 to mesh with the engine gear 1 as shown'in Fig. 3. At this time the starting motor is actuated by suitable means to cause rotation of the power shaft in the direction of the arrow which rotation is transmited through the splined connection to the barrel. The cams l6 thereupon compress the clutch block I5 against the flange member 8 which is thus clutched to the barrel by its frictional engagement with the block IS on one side and the disc II on the other. Th tightening of the clutch so formed proceeds until rotation is transmitted through the flange 8 to the pinion 6 to rotate the engine gear I and crank the engine. When the engine starts, the acceleration of the engine gear causes the pinion 6 to overrun, thus releasing the clutch members, whereupon the parts are returned to their positions by the operator.

If, during the meshing operation, a tooth of the pinion should abut against the engine gear, the longitudinal movement of the pinion is stoppedbut the shifting of the barrel member continues as permitted by the deformation of the portion I8 of the clutch block. When the barrel has been shifted into starting position and the starting motor energized, torque is transmitted through the self-tightening clutch l5, 8, l l to the pinion to index it into proper registry with the tooth spaces of the engine gear, whereupon the portion I8 of the yielding member [5 snaps the pinion into mesh with the engine gear and cranking proceeds in the usual manner.

Although but one embodiment of the invention has been shown and described in detail, it will be understood that other embodiments are possible and various changes may be made in the construction and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

ment thereto.

2. In an engine starter, a power shaft, a barrel member splined thereon, a pinion having a limited telescopic movement in the barrel and an overrunning clutch connection between the bar- 'rel and pinion including a yielding member, said yielding member cooperating with the pinion to normally hold it in extended position with relation to the barrel.

3. In an engine starter, a power shaft, a barrel member splined thereon, a pinion having a limited telescopic movement in the barrel, a friction clutch connection between the barrel and pinion, and torque responsive means for tightening the clutch including a yielding member a portion of said yielding member engaging the pinion to resist telescopic movement thereof.

4. In an engine starter, a power shaft, a barrel member splined thereon, a pinion slidably journalled on the shaft, a flange member in the barrel splined to the pinion, means including an annular block of elastically deformable material in the barrel providing a one-way driving connection from the barrel to the flange member, said block having a portion engaging the pinion to yieldably transmit longitudinal movement from the barrel to the pinion and means for traversing the barrel on the shaft to move the pinion into and out of engagement with a member of an engine to be started.

5. An engine starter gear as set forth in claim 4., including further means for confining and supporting the block of elastically deformable material to prevent its bearing frictionally in the barrel.

6. In an engine starter, a power shaft, a barrel member splined thereon having cam means therein, a pinion slidably journalled on the shaft, a flange member in the barrel splined to the pinion, and an annular block of elastically deformable material in the barrel cooperating with said cam means to provide a one-way driving connection from the barrel to the flange member, said block having a small portion engaging the pinion to yieldably transmit longitudinal movement from the barrel to the pinion.

BURR W. JONES.

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