US2403868A - Camshaft assembly - Google Patents

Description

July 9, 1946. LLOYD 2,403,868

CAMSHAFT ASSEMBLY Filed Aug. 15, 1942 ZSheets-Sheet 1 July 9, 1946. p LLOYD 2,403,868

CAMSHAFT ASSEMBLY Filed Aug. 15, 1942 2 Sheets-Sheet? I M'c/nglans 1 Patented July 9, 1946 UNITED STATES "PATENT OFFICE 12,403,868

CAMSHAFT ASSEMBLY" a 7 Nicholas P. Lloyd, wymiewboa, Pa. Application August 13, 1942. Serial No. 454,700

Claims.

A principal object of this invention isto provide a camshaft assembly for machine tools and the like which shall be of a character to facilitate the operation of changeover from one set of operating cams to another. In machines of certain types such,'for example, as the automatic lathe disclosed in my copending application Serial Number 383,634, several correlated operations of one or more of the machine-elements are controlled, regulated and timed by means of a plurality of cams carried on a common shaft. "Provisionis customarily made for substitution of cams of different forms so as to modify the several operations as required toiproduce a desired final result. With the conventional arrangements, this substitution of cams is atime-consuming one requiring relatively extended shutdown of the machinerduring the changeover period. 4

A principal object-of the invention,as previously set forth, is to provide a device for, effecting a changeover of this character with a minimum period ofshutdown for the machine and in a manner to insure maintenance of a high degree of precision in the operation of the machine;

More specifically, an object of the invention is to provide a cam shaft assembly wherein the shaft consists inpart of a detachable section whichcarries the cam elements and which may be removed bodily for replacem'entby a corresponding section carrying a different'cam combination.

Still another object of the invention is to provide a means whereby the substituted shaft sections may be secured in place in precise predetermined position with respect to the companion shaft section or sections.

The invention further resides in certains'truc tural details and arrangements hereinafter described and illustrated in the attached drawings, wherein: I e

Figures 1 is an elvational and partial sectional view showing a shaft assembly constructed in accordance with the invention; f

Fig. 2 is a section on the line 2-2, Fig. 1;

Fig. 3 is a section on the line 3-3', Fig.2, and

Fig. 4 is an exploded view in perspective showing the several elements of the shaft.

With reference to the drawings, the cam shaft, which is indicated generally by the reference numeral i and which in the present instance is driven through the medium of a gear 2, carries a plurality of cams 3 which are operatively associated in conventional manner with a corresponding number of levers 4 controlling certain of the the 'frame 8 areslotted for reception of a key 9 which functions to position the bearings and to i maintain them in accurate alignment. 7

In accordance with the present invention, the cam shaftl comprisesat least one separable camcarrying section l0 ,*o-neend of which is fitted to and is supported by the relatively fixed portion -Il of the shaft, and the other end of whichlis supported in the bearing 5, as shown in Fig. 1;

and the shaft section 10 o is separable and is adapted to be removed' bodily from the machine for replacement bya similar-shaft section carry-'- ing-a differentset of cams calculated to afford a1desire'd machine operation. "Io this end, the terminal end of the relatively fixed shaft portion I I is formed, as illustrated in Figs. 1 and 4, with an axia1 socket l2 tapering inwardly in the presentinstance and with a U-shaped yoke [3, said socket and yoke being formed for reception respectively of an axial extremity l4 and an adjoining transversely extending arm l5 both on the. s'eparable shaft section I ll. The extremity 4 is tapered in the present instance and, as shown in Figs, land 2, wedges tightly within the tapered recess lz and isof lesser axial length than the recess so as to insure an accurate aligning of the terminal end of the shaft section Ill with the relatively fixed section I I. As shown in Fig.2,

the yoke l3 loosely embraces the arm 15, and one "side of the yoke carries a hardened steel or other suitable button it which forms a solid abutment for one side of the arm' l5 to establish the shaft section [0 accurately in a predetermined angular position with respect to the relatively fixed shaft Means is also provided for clamping the arm l5 solidly against the button l6, and also to. force and maintain the shaft section III in an axial direction toward the section II so as to bind the tapered extremity .M solidly in the recess l2. This'means consists ofa screw I! which is threaded, into a tapped'hole 18 in the other arm of the yoke l3, the inner end of the screw I'l engaging an aperture IS in the arm l5, as shown in Figs. 2 and 3. It will be noted that in the normal assembly of these parts, the tapered inner end of the screw I! will engage one lateral edge of the aperture l9, see Fig. 3, so that the tightening of the screw not only forces the arm l5 solidly 3 against the button Hi, but also exerts a pressure on the arm I5 in the axial direction tending to force the shaft section In towards the shaft section II and to thereby solidly engage the tapered extremity Min the socket It, as previously described.

The aforedescribed construction insures accurate axial alignment of the separable shaft section ill with the relatively fixed shaft section II. and insures also that the shaft section shall have and be maintained in a predetermined angular position with respect to the section I I.

As illustrated, the shaft section I0 is provided in the present instance with a spline or key -2l for locating and retaining the cams 3 in predetermined angular position on the shaft. The cams are separated by spacer sleeves 22,,sone terminal cam bearing against a flange '23 on the shaft section and the other terminal cam "being engaged by a sleeve 24 which is threaded on the shaft, see :Fig. 1, so as to clamp :the entire .cam assembly in position :on the shaft. In the present instance the reduced terminal end 2-5 of the shaft section it which is supported by the hearing 5 is provided at its extremity with a slot 26 which is adapted to receive a corresponding -,rib 2,! on the end of a shaft section 28 whereby this section 28 may be coupled to the section Ill. A sleeve 29 on the shaft section 28 is adapted to be threaded on the end of the shaft section Ill, as shown in Fig. -1, whereby to secure the sections together in axial alignment, the shaft section 28 being supported in the bearing-6, which bearing as previously described is held in accurate axial alignment with the bearing 5. The shaft section 5' 28 is adapted for detachable connection to operating parts of the machine not shown.

If it is desired .to change ,over from one set of cams to another, it isonly necessary to remove the shaft section It and to replace it with another section carrying-the required cams. This permits the cams required for any particular machine operation to be made up on the replaceable shaft section while the machine is still in operation .or the shaft section Ill, with its cams, may be one of a number of permanent inter changeable units. In either case, the machine need be shut down only for the period required to remov the one section Inland to installthe other. 'I'rhisrnay be accomplished by releasin the screw l] to permit axial withdrawal ,of the shaft section 1. from the .socketed end of the relatively fixed section .I I, release of the collar 29 from the end of theshaft section 1.0,, .andsubsequent bodily removal-of the bearing 5 from the frame by release of the studs .1. The shaft section in may then be withdrawn from the bearing 5, the new shaft section insertedand the parts then reassembled in the machine in obvious manner .to complete the .changeover.

There may be modifications in various details of the device without departure from the inven- .tion.

Iclaim:

1. In a coupling for detachably uniting tw shaft sections in predetermined axial and angu lar relation, a tapered axial recess in the end of tone of said sections, a tapered axial extremity on the end of the other section adapted for wedging engagement in said'recess, a laterally projecting arm on one of said sections, an abutment for the said arm on the other of said sections, said arm and abutment establishing a predetermined angular relationship between said sections about the shaft axis, and a tapered fastening element on the last-named section adapted to engage a shoulder on said arm so as to force the arm against said abutment and axially toward the other of .said sections.

'2. In a coupling for detachably uniting two shaft sections in predetermined axial and angular relation, a conical axial recess in an end of one of said sectionsya conical axial extremity on an end of the other section adapted for wedging engagement in said recess, a pair of spaced latorally extending arms on one of said sections, a laterally extending arm on the other section arranged ;to lie between the arms first named when the said sections are in the said wedging engagement, a screw in one of the :arms of said pair operative on the intermediate arm to clamp it laterally against the other armof the pair, and ,interengaging means on the screw and the intermediate arm reactable when the screw is turned in toward the clamping position to draw the shafts together axially into said wedging engagement.

3. .In a coupling for vdetachably uniting two shaft sections in predeterminedaxial and angular relation, an axial socket in the endeof one of said sections, a correspondingly formed extremity on the end of the other section adapted to :fit in .said socket, 'circumferentially aligned laterally projecting arms on said sections coactive to establish a predetermined relative angular ,posi tion ,of the said sections about the shaft axis, and clam-ping means ,operatively associated with said arms for securing the said sections together,

4. In a coupling for detachably a uniting two shaft sections in predetermined axial and angular relation, an axially extending tapered recess in the end of one of said sections adapted for wedging engagement with a correspondingly tapered .end of the other se.ction,;abutment means on one ,of said sections for establishing a predetermined relative angular position of said sections about the shaft axis, an element on the other of the sections for engagement with said abutment means, and a .single securing element coacti-ng with said abutment means and with said-element to retain the sections in the said abutting relation and in said wedging engagement.

.5. In a coupling for detachably uniting two shaft sections in predetermined axial and angular relation, an axially extending tapered recess in the end of one of said sections adapted for Weding engagement with a correspondingly tapered end .of the other section, abutment means on one of said sections for establishing a predetermined relative angular position of said sections about the shaft axis, an element on the other of the sections for engagement with said abutment means, a screw for retaining the element in engagement with the abutment means, and means associated with said screw for exerting axial pressure on said element forcing the sections into said wedging engagement.

NICHOLAS P. LLOYD.

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