US2298408A - Mounting fixture for press assembling - Google Patents

Description

Oct. 13, 1942. o. D. MOYER 2,298,408 MOUNTING FIXTURE FOR PRESS ASSEMBLING Filed Nov. 10, 1939 Patented Oct. 13, 1942 MOUNTING FIXTURE FOR PRESS ASSEMBLING Otto D. Moyer, Indianapolis, Ind.

Application November 10, 1939, Serial No. 303,793

1 Claim.

This invention relates to a fixture for applying to the cam shaft of a Ford or like engine, the driving gear thereof.

At the present time the driving gear is a composition gear with teeth on the periphery, or rim portion of the gear, the latter being connected by spider forming arms or solidly connected to a hub portion in which is mounted when formed and rigidly secured, a metallic sleeve, the axial length of'which is slightly greater than the width of the hub of the gear so that this metallic sleeve projects slightly beyond the hub faces at opposite sides of the gear. In a full metallic gear such extension is not necessary.

Whenever the gear becomes worn or otherwise requires replacement, the cam shaft is removed from the engine and positioned in an arbor press and the gear removed therefrom and then the new gear is pressed on the shaft by said press and the shaft replaced in the engine.

Another Way this gear can be removed from the cam shaft upon which it has been pressfitted, is to drill through and sever the metallic sleeve and to also drill through or break the hub of the composition portion of the unitary gear. Following this removal the new gear is properly positioned adjacent the shaft and pressed on the shaft. This removal may be accomplished with or without removal of the cam shaft from the engine.

The difficulty has been heretofore in securing uniform and sufficient pressure on the gear or the metallic sleeve of a combination gear so that it can be forced, when properly located, onto the cam shaft while in the engine and in proper position, both with respect to ignition timing and valve timing or more particularly with respect to its axial position on said shaft.

The chief object of the invention, therefore, is to provide a fixture which may be applied to an engine of this general character and which is adapted to nestingly receive a gear of this character and when the fixture is properly located and secured to the engine with the gear nested in the fixture, the gear may be forced or pressfitted upon the shaft, all without requiring the removal'of the cam shaft from the engine.

The chief feature of the invention consists in providing a fixture which has a central hub portion having a threaded bore therethrough and from which hub portion projects radial outwardly and forwardly directed arms with terminate in anchoring portions adapted to register with certain anchoring portionsof the engine so that the fixture is accurately located with respect to its subsequent operation when it is attached to the engine.

Of course, it is to be understood that this device can be used with a metallic gear, as well, and for the mounting of the same.

Also when metallic gears are to be replaced and when desired or possible the composition gear may be removed with a conventional gear puller.

However, the utility of the fixture is most obvious when associated with a composition or other relatively fragile material gear. 7

Other objects and features of the invention will be set forth more fully hereinafter.

The full nature of the invention will be understood from the accompanying drawing and the following description and claim:

In the drawing, Fig. 1 is a central sectional View through the cam shaft mounting portion of the engine with the engine cover portion removed and replaced by the invention, the cam shaft supportable gear being nested relative thereto, and the view being taken on line ll' of Fig. 2 and in the direction of the arrows.

Fig 2 is' a front elevational view of the parts illustrated in Fig. 1.

Fig. 3 is a perspective View of the uniform pressure applying gear contacting member. 7

In the drawing, ll] indicates a body portion of an engine and H a cam shaft rotatably'mcunted in the bearing 12 of said engine portion it and including an enlarged and engine body exposed portion l3 having an ignition drive slot l3a in the end thereof. A flange I'd is provided on the body with a suitable number of spaced openings l5 which are threaded and these openings receive bolts for mounting a cover forming a chamber, indicated generally by the numeral I6, which encloses a driving gear.

This gear includes ahub portion H with arms or spokes radiating'therefrom and indicated by the numeral l'l'a a'nd'a peripheral or rim portion !9 in which is formed gear teeth 2%]. The hub portion ll isreenforced by a metallic sleeve structure l3 secured within the opening llb in the hub portion ll when thecompositiori portion is formed.

This metallic sleeve is rigid with the remainder of the gear. It has, as shown in Fig. 1, a length slightly greater than the width of the gear hub so that as indicated at Zia and 21b, it projects beyond'the side faces of the gear hub. I The project'i'ng portionz'la may bear against the face 22 of the bearing l2. The gear is "press-fittedon to the portion l3 of the cam shaft.

Whenever the wear on the teeth 20 becomes excessive so that the back lash resulting therefrom introduces a lag in ignition as well as valve operation or one or more teeth are broken out, or for any other reason the gear breaks, and this usually occurs at the arm portion I8, if so constructed, the gear requires replacement. To replace such defective gear with a new gear requires removal of the defective gear by breakage or great pulling power, because the gear has been mounted at the assembly plant in a press arrangement that is capable of exerting enormous pressure. One practical way of removing such defective gear without removing the supporting shaft from the engine is as follows:

A small drill is utilized and a radial or like series of holes is drilled through the hub portion I1 and through the metallic sleeve I8. This immediately relieves the constricting pressure and this gear can then be readil removed from the supporting portion I3 of the cam shaft II. Another method of removal is by using a conventional gear puller.

This type of engine structure is found in the Ford V-8 engine and the Lincoln-Zephyr engine and possibly several others. The pressure lock between the gear and th cam shaft, it will be understood, must be sufficient to prevent the gear from slipping on the shaft, since this gear is the driving gear for the cam shaft as Well as the ignition drive.

After th old gear has been removed from the shaft, without shaft removal from the engine, it is indeed a problem for the average automotive mechanic or garage attendant to apply sufficient pressure to the new gear for mounting the same. It is also a problem how to apply such pressure necessary to mount the new gear on the cam shaft without accidental shattering or breaking the composition portion of that new gear.

Of course, when the shaft is removed from the engine, the new gear may be easily mounted, if an arbor press is available. Such procedure, however, is naturally time consuming and, therefore, expensive. Also in such operation there is danger of damaging the cam portions of the cam shaft.

The present invention constitutes a fixture which may be readily applied to the engine following removal of the cover and removal of the old gear, the former being necessary to effect the latter. This fixture is detachably mounted on the engine and is made to conform to the cover supporting openings of the engine so that the pressure applying or thrust receiving portion of the fixture is in axial aligmnent with the cam shaft axis.

The fixture preferably includes a somewhat open work arrangement so that the mechanic can observe the zero or indicating mark on the gear and hav it conform or align with the indicating mark on the cam shaft so that the new gear when replaced will be in exact predetermined proper position to insure proper and perfect timing of the engine ignition system.

The present invention also includes an arrangement whereby an enormous pressure, relatively speaking, can be applied to the new gear in order to obtain the proper press fit mounting of the new gear on the cam shaft.

The present invention also includes an arrangement whereby the pressure is applied solely to the metallic sleeve portion of said gear, if of the character previously described.

Th fixture hereinbefore briefly described includes a central portion 30 with a bore 3| there through which is threaded to receive a bolt 32 having a tool engageable head portion 33. This is shown herein in the form of nut type so as to -be receivable by a socket wrench or ordinary wrench.

Radiating from the hub portion 33 is a plurality, and preferably three or more and herein five are illustrated, of radial arms 34. Each of these arms 34 terminates in a boss 35 which is apertured as at 33 to receive a bolt 31 having th nut portion 38 adapted to bear against the flange 39 of the boss 35. The opposite face of said boss, herein indicated by the numeral 40, is adapted to bear against the forward face 4| 0f the engine body flange I4 and the hole 36 registers with the threaded hole I5. The threaded hole I5 receives the threaded end of the bolt 3'I-38.

As previously stated, the radiating arms 34 are arranged in spaced relation to each other and are arranged so that the various bosses 35 register with the openings I 5 in the flange I4 of the engine body portion.

As shown clearly in Fig. 1, the arms 34 project outwardly from the hub portion 30 and angularly thereof, forming, as it were, a pocket portion in which may be nested a gear as shown in Fig. 1. This is necessary because the bosses 35 contact the face 4| of the flange I4 and the end of the shaft I3 terminates immediately adjacent to the plane of this face 4I and Within the chamber I3. Therefore, this fixture must be of chambered character to receive and nest the gear to be mounted on said shaft.

The end of the pressure applying screw or bolt is preferably of conoidal form as indicated at 42. A pressure plate or pusher plate 43 has a complementary or hemispherical recess 44 therein to receive such bolt end.

Referring to Fig. 1, it is to be understeod that following the removal of the engine cover portion referred to and removal of the defective gear, the fixture or spider formation is applied to the engine body portion and rigidly anchored thereto. This takes but a few moments. Previous to such anchorage of fixture, it is to be understood there has been nested in the fixture the replacing gear as Well as the pusher plate. After rigid mounting of the fixture upon the engine, the gear is aligned, as aforesaid, for perfect timing operation. The pusher plate 43 previously nested within the fixture, then is caused to engage the face ZI b of the metallic sleeve, if the gear be as illustrated herein, and is held in that position by properly turning the pressure applying screw 32 through the head 33. With the gear properly aligned and with the opening I 8a in the metallic sleeve registering with the exposed portion I 3 of the shaft, further operation of the screw 32 advances the pressure or pusher plate 43 toward the end I3 of the shaft, carrying with it the sleeve I8 and the gear portion carried thereby. This screw operation is continued until no further movement axially of the gear on the shaft bearing I3 can be effected and at this time the face 2Ia of the metallic sleeve I8 will be substantially coplanar with the face 22. Removable shims may be included therebetween, if desired.

It is, of course, to be understood that such bearing is of such character that friction therebetween is insufficient to cause any drag between the cam shaft I I and the gear structure. It is preferred, of course, that there is no actual physical contact between the end 22 and the face 2la of the metallic sleeve.

It is to be observed from the aforesaid that enormous pressure can be applied to the gear and in a relatively easy manner and in only the proper direction.

The present invention permits gear replacement in a very short period of time and without any of the dangers incident thereto, which heretofore have been inherent in gear and the like replacement operation by other than the automotive manufacturer.

This fixture, it is evident, is relatively simple, relatively inexpensive and is foolproof and positive insofar as location, use and the like are concerned.

While the invention has been illustrated and described in great detail in the drawing and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claim.

The invention claimed is:

A device for mounting a gear upon a shaft in a housing having a cover detachably bolted thereto to form a gear or the like, enclosing chamber, said device including a concave spider arrangement having a central threaded portion adapted for axial alignment with the shaft axis when the device is mounted upon the housing, and a plurality of curved, rigid arms integral with the cen tral portion each terminating in an elongated axis parallel free end, each being apertured for bolt reception and anchorage to the housing when the cover is removed, the curvature of said arms and elongated ends defining a chamber for nesting a gear or the like adjacent and in alignment with the shaft, a threaded pressure applying member in said threaded portion for pressure mounting of the gear upon the shaft, and. means comprising a comparatively flat bearing plate of appreciable area having a pressure applying face and an opposite face including a central recess, the threaded applying pressure member having a partial spherical exposed end seatable in and bearable upon the plate recess for axial pressure transmission in aligned relation.

OTTO D. MOYER.

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