US2915903A - Engine starter drive for internal combustion engines - Google Patents

Description

Dec. 8, 1959 J. J. DIGBY ETAL 2,915,903

ENGINE STARTER DRIVE FOR INTERNAL COMBUSTION ENGINES med m s. 1955 2 sheewsheet 1 zz? 119816@ fzswfaeafzzs Il a i? f i P: z a I t i 954i 1 4 l# l Dec. 8, 1959 J. J. DlGBY ETAL 2,915,903

ENGINE 5mn-'IER DRIVE Foa INTERNAL coMBUsIIoN ENGINES Fund nay s. 1955 I 2 sheets-sheet 2 NVNTORS 27h/nes j @@4 WITNESS: BY Wha/ce ZOZJ/ A ORNEY United States Patent lO ice ENGINE STARTER DRIVE FOR INTERNAL COMBUSTION ENGINES James I. Digby and Maurice P. Whitney, Elmira, N.Y., assignors to Bendix Aviation Corporation, Elmira Heights, N.Y., a corporation of Delaware Application May 3, 1955, Serial No. 505,665 4 Claims. (Cl. 74-7) The present invention relates to an engine starter drive for internal combustion engines, and more particularly to the so-called barrel type in which the drive pinion is actuated from the control nut through an intermediary in the form of a barrel member.

In the barrel types of starter drive as shown for instance in the patents to Buxton 2,609,695 issued September 9, 1952, and Strozinski 2,673,467 issued March 30,

to include said lugs, the body of the control nut being J1 turned down and milled inlsuch manner as to leave the lugs projecting therefrom. Since the cost of bar steel increases rapidly with its diameter, and the above operations involve removing a substantial portion of the original stock, it is obvious that the control nut so formed is a v comparatively expensive part as respects both material and fabrication. On the other hand, the use of keying elements formed separately and mounted on the control nut has not proved a satisfactory solution of the problem.

It is an object of the present invention to provide a novel engine starter drive which is well adapted to withstand the forces encountered in use and is economical to manufacture as respects material, fabrication and assembly.

It is another object to provide such a device in which the parts may be readily disassembled for selective re placement.

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

Fig. l is a side elevation partly broken away and in section of a preferred embodiment of the invention;

Fig. 2 is an end view of the control nut;

Fig. 3 is a section of the control nut on the line 3-3 of Fig. 2',

Fig. 4 is an end view of the barrel member;

Fig. 5 is a section of the barrel member on the line 5-5 of Fig, 4;

Fig. 6 is a side elevation partly broken away and in section of a second embodiment of the invention;

Fig. 7 is an end view of the barrel member shown in Fig. 6;

Fig. 8 is a section of the barrel member on the line 8-8 of Fig. 7;

Fig. 9 is an end view of a modified form of barrel member with the control nut anchored therein; and

Fig. 10 is a section taken on the line 10-10 of Fig. 9.

In Fig. 1 of the drawing, there is illustrated a power shaft 1 on which a sleeve 2 is fixed in any suitable manner as indicated at 3, The sleeve 2 is provided with a smooth Patented Dec. 8, 1959 reduced portion 4 providing a shoulder 5. A screw shaft 6 is slidably journalled on said reduced portion 4.

Means for yieldably actuating the screw shaft 6 from the sleeve 2 is provided comprising an anchor plate 7 non-rotatably mounted on the sleeve, a second anchor plate 8 non-rotatably mounted on a driving overrunning clutch member 9 slidably journalled on the smooth portion 4 of the sleeve, land a coiled drive spring 11 having out-turned ends 12 and 13 entering corresponding slots in the anchor plates 7, 8.

The clutch member 9 is provided with teeth14 adapted to cooperate with similar teeth 15 on the adjacent end of the screw shaft 6. Stop ring 16 seated in a groove in the sleeve member 4 occupies a counterbore in the clutch member 9 and serves to limit its longitudinal movement to the right and thereby places the drive spring 11 under slight initial compression.

A pinion 17 is slidably journalled on the power shaft 1 for movement into and out of mesh with a gear 18 of the engine to be started. Means for actuating the pinion 17 from the screw shaft 6 is provided comprising a control nut 19 and a barrel member 21 iixedly mounted at one end on the pinion 17 as indicated at 22, and at its other end rigidly connected with the control nut 19 in a manner to be more fully described.

The idle position of the control nut on the screw shaft is defined b-y the ends 23 of the threads of the screw shaft while the meshed position of the control nut and .pinion assembly is defined by an abutment ring 24 fixed on the end of sleeve 2 by means of a lock ring 25 seated in a groove in said sleeve. A spring washer 26 located between the end of the screw shaft and the abutment ring 24 normally holds the teeth 15 of the screw shaft in engagement with the teeth 14 of the clutch member 9, a thrust washer 27 being preferably interposed between the screw shaft and the abutment ring.

In accordance with the present invention the control nut 19 has a sliding lit within the end of the barrel rnember 21, and is provided with a plurality of axially extending peripheral channels or notches 28 (Fig. 2). The barrel member is provided with a corresponding plu# rality of inwardly extending arms 29 (Fig. 5) which are partially sheared and pressed inwardly and formed with portions 31 adapted to fit in the channels 28 of the control nut.

The arms 29 are provided with shoulders 32 acting as abutments for the control nut 19, and a lock ring 33 (Fig. 1) seated in a groove 34 in the free end of the barrel member holds the control nut against said shoulders.

In order to prevent the pinion and barrel assembly from drifting away from idle position, the threads of the screw shaft 6 are reduced in diameter adjacent the idle position of the control nut to form inclined shoulders 35; and one or more spring pressed detents 36 are mounted in the control nut in position to engage said shoulders as the control nut moves away from idle position and thereby yieldingly resist such movement.

In the operation of this embodiment of the invention, rotation of power shaft 1 by the starting motor, not illustrated, is transmitted throughthe sleeve 2, the yielding driving connection including the spring 11, and the overrunning clutch member 9 to the screw shaft 6, thereby causing the control nut 19 to move the pinion 17 into mesh with the engine gear 18 until the meshing movement is arrested by the abutment ring 24, after which the screw shaft 6 is forced backward, compressing the spring 11 until the backward movement of the clutch member 9 is arrested by the shoulder 5 of sleeve 2. The pinion 17 is then rotated to crank the engine. When the engine lires, the overrunning action causes the pinion s tained by means of anti-drift detents barrel. `similarly to the control nut 19 in the first embodiment lof the control nut is transmitted to `by means of shoulders 43 assembly to be returned to idle position where it is main` the pinion assembly and screw shaft being permitted l by the clutch connection 14, A15.

In Figs. v6 to` 8 there is illustrated a "starter drive similar to that shown' in Figs. 1 to .5 inclusive but embodying a modified anchorage of the control nut to the As there shown, the control nut 19' is formed of the invention, and is provided with notches 28. The barrel member 21 s.formed with inwardly extended bars 40 which Y,are sheared and pressed inwardly from the body of the barrel but which are left attached to the barrel at both ends as indicated at 4142 (Fig. 8'). The bars 40 are` of such width as to snugly lit `within the notches 28' of the control nut 19. Meshing movement the barrel member which are partially sheared and pressed inwardly from the body of the barrel in position to abut against the side of the control nut 19. `The control nut is held in the barrel in engagement with the shoulders 43 by means oflock ring 33' seated in a groove 34 in the free endV ofthe barrel.

The remaining parts of this embodiment of the drive are the same as those.il1ustrate d in the first embodiment *andare similarlyV numbered, `and thevoperation of Vthis embodiment is the same as previously described.

In Figs. 9 and 10 of the drawing there is illustrated a slightly modiiied form Vof barrel member 21. As there shown, instead of vforming the groove 34 for reception of the lock ring 33 asin Figs. 6 and 7, in this case the lock ring 33 lits slidably in the open end of the barrel, and strips from the rim of the barrel at angularly spaced points are shearedV and `bowed inwardly as indicated at 44 (Figs. 9) toretain the lock ring in place.V The bowed stripsv44 are preferably aligned Withthe keying bars 40, so that when the lock ring 33" is removed, Vthe control nut 19' can be slidout of the barrel. Y Although certain structure has been shown and described in detail, it will be understood that other embodiments are possible and changesmay be made in the design and arrangement of the parts without departing from the spirit of the invention.. l

We claim: Y Y

1. -In an engine starter drive a power shaft, asleeve 36; overrunning of iixed thereon, a screw shaft slidably journaled on the sleeve, a yielding driving connection from the sleeve to the screw shaft, a pinion slidably journaled on the power shaft, and means for actuating the pinion from the screw shaft including a cylindricalbarrel member fixed at one end to the pinion, its other .end being open, a control nut threaded on the screw shaft slidably fitting in the open end of the barrel, said control 'nut having a plurality of axially extending peripheral channels with flat,

parallel, substantially radial sides; said barrel having a corresponding number of integral rectangular axially extending keying barsoi-set inwardly from the body of the barrel received inand tightly fitting said channels; thegbarrel also having a plurality of circumferentially arranged inwardly extending integral shoulders forming a thrust bearing for the control nut, and means for holding the control nut against said thrust bearing including a lock ring anchored in the barrel inabutting relation to the control nut.

2. A starter drive as set forth in claim 1 in which vthe intermediate portions of the keying bars separated from the barrel and displaced inwardly to engage in the channels of the control nut, the ends of the Vbars remaining integral with the body of the barrel.

3. A starter drive as set forth in claim 2 in which the means for preventing relative longitudinal movement of the control nut'and barrel includes a plurality of abutments partially vseparated and displaced inwardly from the body of the barrel, and having flat terminal surfaces forming stops for the control nut in the barrel.

4. A starter drive as set forth in claim 2 in which the means for preventing relative longitudinal movement of the control nut and barrel includes a thrustV ring seated in the open end of the barrel against said control nut;

lthe rim of the barrel having a plurality of arcuatestrips References Cited in the file of this patent UNITED STATES PATENTS 2,089,168 Brown Aug. 3, 1937 2,475,042 McCloskey Iuly 5, 1949 2,609,695 Buxton Sept.V 9,V 1952 1954 2,673,467 Strozinski Mar. 30,

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