US1955233A - Cam - Google Patents

Description

April 17, 1934. A. G. GILBERT 1,955,233

CAM

Filed Sept. 26, 1932 INVENTOR:

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Patented Apr. 17, 1934 CAM Alfred G. Gilbert, South Acton, Mass., assignor. to Reece Folding Machine Company, Boston, Mass, a corporation of Maine Application September 26, 1932, Serial No. 634,915

4 Claims.

This invention relates to a rotary cam, such as a cam turned by a shaft and operating through a roll or other follower to transmit motion with a predetermined timing to machine parts of va- 5 rious 'kinds; and to a machine in which the same is incorporated.

As an illustration may be mentioned the use of the present invention in machines for infolding the blanks for collars, cuffs and the like,

for which use the invention has been practically developed and designed. In this and other classes of machine it is frequently desirable to change or interchange the contour and resulting motion at one part of a rotary cam relatively to or without alteration ofthe main or other part of the contour and resulting motion, such change consisting either in a change of timing, or a change of motion or throw, or both.

To avoid illustration of a complete machine embodying the cam of this invention reference will be made to certain prior patents in the folding machine art with which the invention might be used. In Dixon Patent 956,950 of May 3, 1910, the die or templet is lowered and lifted through lever and link connections by a cam G shown as an outside cam upon whichthe roll or follower is held by the weight of the die or templet. The cam is contoured with a'dwell to hold the templet normally elevated and with inclines to lower and raise the templet, and a cam portion between determining the lowered position of the templet and any vertical motions to be caused during this part of the cycle. Without changing the general lowering and lifting movements it may be desirable to change from time to time the cam contour which is in effect while the templet is down, due to various causes such as changes in thickness of blanks. Another illustration is Reece Patent 972,916 of October 18, 1910, wherein again the weight of the templet causes the follower to press upon the periphery of "the lowering and lifting cam i and wherein while the templet is lowered certain slight vertical movements or pressures are brought about, as indicated by the shown contour. A later illustration is the Dixon Patent 1,648,450 of November 8, 1927, wherein the weight of the templet causes the cam. roll to bear on the periphery of the cam 81, which at a certain point in the 5 cycle causes the templet to be lifted bodily to a slight extent and redeposited upon the blank. Another instance is Dixon 1,797,641 of March 24, 1931, wherein thecam 33 has general portions for the lowering and lifting of the templet,

55 and special contours'operating while the templet is lowered to raise or relax slightly the templet to facilitate its contraction. Analogous operation of the infolders is similarly disclosed, these having general lifting and lowering movements to bring them to and from position and addi- 60. tionally certain slight or minute movements for effecting pressure and thereafter lifting to relax pressure.

In machines of the class referred to there are frequent changes in the particular kinds of work handled and in the particular requirements of different manufacturers, with the consequence that frequent readjustments, or interchange of parts, have been necessary, and in the cases of the cams this not infrequently requiring entire interchange of cams, and the maintaining at hand of sets of cams available for the different conditions or adjustments to be encountered.

The main object of the present invention is to afford an adjustable cam which will minimize or obviate the need of interchange of cams for effecting minor changes of contour, timing and resultant movements. In the class of machines referred to this improvement effects an important labor saving in adapting the folding mago chines to various conditions and demands of the work, referring either to templet cams, infolder cams or other cams; and similar principles are of utility in various other classes of machine, unnecessary to enumerate. Further objects and 35 advantages of the present invention will be pointed out in the hereinafter following description of an illustrative embodiment thereof or will be understood to those conversant with the subject.

To the attainment of such objects and advan- 99 tages the present invention consists in the novel adjustable cam, and machine embodying the same, and the novel features of combination, construction and arrangement herein illustrated or described.

In the accompanying drawing Figure l is a face view of an adjustable cam embodying the present invention and shown engaged by its roll or follower, together with the principal parts of an infolding machine embodying such cam.

Fig. 2 is a central vertical section of the cam shown in Fig. 1, taken on the section line 2-2.

Fig. 3 is a perspective of the inner or adjustable cam. part detached.

Similar reference numbers designate corresponding parts in the several figures. 7

Referring first to the accompanying machine parts the frame 5 of a blank infolding machine may be of conventional form giving support to a fixed bed 6 on top of which is mounted the blank follower 21 is about to pass position 9 to 9 retained while the supporting surface or pad '7. Cooperating therewith to infold the margins of the blanks is a system of infolders 8 which are diagrammatically indicated, and the further details of which, and their mode of operation, may be ascertained by reference to well known infolding machines such as those shown in said prior patents.

During infolding each blank is defined by a templet or die 9 comprising usually a series of thin plates which may be expanded to the contour to be infolded and may be contracted to withdraw from the infolds after the infolders have moved inwardly. For convenience a templet has been shown substantially as in said Dixon Patent 956,950. It is the common prac- 'se to lower the expanded templet upon the goods resting upon the bed pad and thereupon move inwardly the infolders to form the marginal folds of the blank, followed by the retraction or contraction of the plates of the templet and there upon a squeezing action by which the folds are creased and fixed by pressure between the infolders and the bed. It is frequently desirable to afford a slight lifting or relaxing movement of the templet after the infolding and preparatory to the retraction of the templet, so that during the retraction the fabric will not be wrinkled or pulled out of place by the retracting movement.

The templet 9 is shown in full lines in its slightly elevated or relaxed position ready for contraction. In dotted lines it is shown at 9 in its fully lowered position bearing upon the fabric blanks and substantially supported by the bed. The slight lifting movement from position 9 to position 9 may have to be adjustably varied for different conditions of work. After the successful contraction of the templet it may be swung upwardly clear of the bed to the dotted position 9', which will be uniform notwithstanding adjustments of the lowered and slightly elevated positions. conventionally the plates of the templet are shown mounted at the lower ends of the carrier bars 10 which bars are slidingly mounted ina templet body 11 which carries templet contracting devices operated for example by a bar 12. The entire templet and operating devices are mounted at the forward or free ends of a pair of carrying arms 13 mounted upon a rear axle 14 journalled in an upstanding bracket 15 at the rear of the machine frame. A rear arm 16 extends from the axle l4 and this arm is connected by a'downwardly extending link 17 to the rear arm 18 of a bell crank lever fulcrumed on an axle l9 and having its forward arm 20 extended at an upward slant and carrying a roll 21 bearing on the cam to be particularly described. The elements thus far described are substantially conventional and well known.

Mounted in the lower part of the machine frame is the operating shaft 25. This is formed with a keyway 26 occupied by a key or spline 27 upon which is engaged a cam disk 28, the hub 29 of which is formed with a complementary keyway 30 engaging the key 27. These parts and the cam disk may be permanently secured in place upon the shaft by a set screw 31.

The cam disk 28 carries a cam surface or flange comprising a dwell portion 33 which is followed by an inward incline or slant 34 and is preceded by an outward slant or rise 35, the cam and shaft turning clockwise as seen in Fig. 1, where the on to the rise 35, of the templet from this elevated position being cam roll is in engagement which will effect the elevation disk and leading directly to the with the dwell 33, the incline 34 subsequently allowing the templet to be lowered by gravity to its full lowered position 9*. The cam flange 35-33-34 is seen to occupy less than 360, the portion corresponding with the lowered position of the templet being vacant except as occupied by the adjustable cam part to be described. Usually the main cam surface may be an open or outside cam, gravity holding the roll to the cam. The cam however might be a closed cam with the roll controlled in both directions, and the drawing illustrates an exterior or confining cam portion 37 of short angular extent having a slant 38 corresponding with the slant 34 and a dwell 39 corresponding with the full lowered position ofthe templet, so that during this part of the action the templet is positively lowered and held down upon the bed without reliance upon gravity.

The main cam 28 is shown as having an area 41 of reduced thickness, the inner edge of this bounded by a circular shoulder 42 enclosing a partial circular recess 43 within which is accommodated the shiftable cam part 45 determining the position, the motions and the timing of the templet during the part of the cycle while the templet is lowered and when the cam roll 21 is between the main cam slants 34 and 35. The shiftable cam part 45 has a hub 46 and is interiorly formed with a number of keyways 4'7, any one of which may be engaged with the key 2'7, and with set screws 48 engaging in threaded holes 49 by which in any adjustment the cam part 45 may be fixedly secured to the shaft 25.

The adjustable or inner cam part 45 is shown as divided into four peripheral sections, and with four keyways 47 determining which of the cam sections is to be in operative position and act upon the cam roll 21. According to conditions the number of cam sections and keyways might be increased to five or six or more, affording that many adjustments and sets of conditions of the cam.

It will be noted that notwithstanding any adjustments of the shiftable cam part 45 the templet lifting and lowering movements and the fully elevated templet position are constant. There is no need for adjustment in the operating train of connections and while the link 17 is shown adjustable in length it would be impracticable to secure the desired changes through adjustment thereof, and the present invention operates by the mere shift of the inner cam part 45 from one to another of its several positions.

The upper side of the shiftable cam part is shown in Fig. 1 as in effect. It comprises a lower dwell 50 following a short continuation of the main cam slant 34. When the roll is running on the dwell 50 the templet is in its fully lowered position and during this part of the cycle the infolders will operate. Following the dwell 50 is a slight incline or rise 51 which causes a corresponding rise of the cam roll and the slight lift of the templet from position 9 to 9. After the cam rise 51 follows a dwell 52 during which the templet may be contracted. 'I'his dwell in turn is followed by a short dwell 53 from which the cam roll passes on to the main cam incline 35 which operates to lift the templet from position 9 to 9*. Each of the four sections of the cam part 45 may be similarly constructed with a lower dwell 50, 50 etc., a slant 51 etc., a higher dwell 52, 52 etc., and atop surface 53, 53* etc. preferably contacting the shoulder 42 of the main cam incline or rise 35 of the main cam. The respective adjustments ill) are simply made by loosening the setscrews 48 of the shiftable cam part 45, sliding the cam part endwise until it has disengaged the key, turning it until the selected keyway alines with the. key, restoring the cam part endwise to position, and retightening the set screws.

The difference between the several sections of the shiftable cam part may reside in the different depths or heights of the several portions of the contour, and the timing thereof. For example all of the lower dwells 50, 50 etc. may if desired be at the same effective height, so that the templet always descends to the'same point 9 The higher dwells 52, 52 etc. however may all be at different heights, as shown, so that the relaxed or slightly elevated position 9 of the templet may be adjustably varied up or down between four different positions or adjustments, according to the work to be performed or the conditions encountered. The normal lowered position of the templet is thus constant, as well as the fully elevated position, and due to the rigid character of the main cam the general lowering of the templet and its subsequent lifting remain unchanged, the adjustments relating wholly to the delicate operations of the templet in shifting between its fully lowered position and its slightly relaxed or lifted position. Manifestly the timing of the slight lift may be changed by a shift of the cam rise 51, while the lifted position is changed by the elevation of the dwell 52 as described, and if desired the fully lowered position could be adjusted by reason of differences in the radii of the lower dwell 50.

A result is thus permitted which is not obtainable either by adjustment of the transmitting connections or by bodily adjustment of the entire cam on the shaft. As stated it has been customary to change an entire cam for a different one, with great labor; and this invention largely obviates such difficulty and permits ready and quick adjustment as between several differentconditions, without detachment of parts, and by the mere loosening of the adjustable cam part, its retraction, rotation, restoration and attachment to the shaft.

There have thus been described a rotary cam and a machine embodying the same which em body the principles andattain the advantages of the present invention. Since various matters of combination, arrangement and construction may be modified without departing from the principles of the invention, it is not intended to limit the same to such matters except so far as set forth in the appended claims.

What is claimed is:

1. A rotary shaft cam for timed operation of machine parts, the same comprising a plurality of cam parts affording a combinedcontour for actuation of a follower, namely an outer cam part fixed to the shaft, and an inner cam part being attached in a manner to permit its independent loosening and relative adjustment and reattachment, and adapted to be rotated into different adjustments when loosened, the shaft having a key and the rotatable inner cam part having several keyways selectively engageable with the key; whereby the inner portion of the total contour can be adjustably altered without altering the remainder of the contour of the cam.

2. A rotary cam for the timed operation of machine elements, the same comprising a main cam part having an interrupted exterior contour, and a subordinate cam part occupying the interruption of the main cam contour and operating consecutively with the main cam and affording therewith a combined contour for the actuation of a follower and connected elements, the subordinate cam part having plural key-and-way means fixing its relation to the main cam part, whereby the subordinate cam part is loosenable and rotatable between different positions for adjustment of its effective contour and again fixed, whereby the action of the cam at the subordinate contour may be adjustably altered without changing the action of the main cam part.

3. A cam as in claim 2 and wherein the subordinate cam part comprises several contour portions of differing contour selectively adjustable into operative relation to the main cam part.

4. A rotary shaft cam for timed operation of machine parts, the same comprising a plurality of cam parts affording a combined contour for actuation of a follower, namely an outer cam part fixed to the shaft, and an inner cam part being attached in a manner to permit its independent loosening and relative adjustment and reattachment, and adapted to be rotated into different adjustments when loosened, the shaft and the rotatable inner cam part being connected by several selectively engageable key and keyway devices; whereby the inner portion of the total contour can be adjustably altered without altering the remainder of the contour of the cam.

ALFRED G. GILBERT.

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