US2735684A - Retaining a rotatable member - Google Patents

Description

Feb. 21, 1956 c, LQNGEE ETAL 7 2,735,684

SELF-CLOSING SAFETY MECHANISM FOR RELEASABLY RETAINING A ROTATABLE MEMBER Filed Dec. 21, 1954 2 Sheets-Sheet 1 A1 TORNEY Feb. 21, .1956

Filed Dec. 21, 1954 NGEE El AL 2,735,684

N. C. LO SELF-CLOSING SAFETY MECHANISM FOR RELEASABLY RETAINING A ROTATABLE MEMBER 2 Sheets-Sheet 2 IN VEN TORS #516 0/1 6'. (04 655 PMZAQV ATTORNEY United States Patent O SELF-CLOSING SAFETY FOR RELEASABLY RETAINING A ROTATABLE MEMBER Nelson C. Longee, Oakland, Nufer Go'dzyk, Jr., Clifton,

V and Zoltan D. Fodor, Lodi, N. J., assignors' to United States Rubber Company, New York, N. Y., a corporationof New Jersey Application December 21, 1954, SerialNo. 476,664

11 Claims; c1. 219-1 7 This invention relates to a self-closing safety mechanism for releasably retaining a rotatable member, and more particularly to a self-closing safety mechanism comprising a chuck and collar for holding the core bars of rolls used for carrying fabric.

In any manufacturing operation involving the use of rolls for carrying fabric, there is an unwind and a rewind phase, customarily called let-off and wind-up. In each case, a core bar (usually of square cross section) is inserted in the roll, which is then hung in a pair of chucks. Since the rolls are heavy, hoisting equipment is provided to lift the rolls into and out of the chucks. One chuck is often fixed in the closed position, so it becomes, in effect, a square socket. The other chuck must be free to open, so it is provided with a U-shaped socket and a full-circle collar which slides back past the end of the bar in the open position, or forward the depth of the chuck in the closed position. Ordinarily, a spring loaded pin is provided on the collar or the chuck to hold the collar either open or closed, and frequently an operator will forget to close the collar before the roll starts to revolve, thus allowing it to fall which often results in personal injury and property damage.

Accordingly, an object of this invention is to provide a self-closing safety mechanism wherein the chuck will automatically be closed by the collar upon rotation of the roll, thereby eliminating the manualclosing of the collar.

Another object of the invention is to provide a selfclosing safety mechanism wherein the collar can only open the chuck inone rotative position whether the mechanism is rotating or stationary.

A further object of the invention is to provide a selfclosing safety mechanism wherein the core bar and roll cannot fall out of the chuck atany time, thus eliminating personal injury and property damage.

Other objects as well as advantages of this invention will become apparent upon consideration of the following specification and claims when read in conjunction with the accompanying drawings wherein:

Fig. 1 is a top plan view illustrating the roll and core bar mounted in the safety mechanism embodying this invention;

Fig. 2 is an elevational sectional view on line 22 of Fig. 1 and illustrates the front face of the safety mechanism;

Fig. 3 is a side elevational view of the safety mechanism;

Fig. 4 is a side elevational view taken partly in section on line 44 of Fig. 2, and illustrates the collar slid back to open the chuck, whereby the core bar and roll may be lifted into or out of the safety mechanism, and

Fig. 5 is a view similar to Fig. 4, but it illustrates the collar slid forward to close the chuck.

Referring particularly to Fig. 1, there is shown a roll 13 for carrying fabric. The roll is preferably constructed of wood and is supported by a metal core bar 11 which is substantially square in cross section. At each end the 2. core bar 11' is supported by the self-closing safety mechanism, generally indicated at 12. If desired, the core bar 11 may be provided with cylindrical portions, 11a to' facilitate engagement with hoisting hooks (not shown) for lifting the core bar 11 and roll 10 into and out of the safety mechanisms. Although two mechanisms 12 are shown, it will become apparent that one will suflice, the other core bar support comprising a square socket.

Basically, the self-closing safety mechanism 12 comprises the chuck 13, the collar 14 and the support generally indicated at 15. The chuck 13, which is preferably made of cast steel, has a reduced shaft 16 at one end. Shaft 16 is rotatably mounted in bearings 17 which are rigidly supported on a vertically extending I-beam 18 of support 15, by bolts 1%. Theshaft 16 is prevented from sliding relative to the bearings by collars 20. At the other end, the chuck 13 has an enlarged cylindrical head 21 having an axially extending U-shaped slot 22 for receiving the square end of core bar 11, asclearly shown in Fig. 2.

An annular, machine steel collar 14 is slidably mounted over the head 21 of chuck 13 and has a depending lug 23 which extends part way into the U-shaped slot 22 to form a substantially square opening in the chuck which snugly fits the square end of core bar 11. Collar 14 is prevented from rotating relative to chuck 13 by lock bolts 24 which pass through the collar andextend into axially extending channels 25 in the chuck. Bolts 24 and channels 25 also act as guides to prevent cocking or canting of the collar as it slides. As seen in Figs. 1, 4 and 5, the collar 14 is slightly less than half as thick as chuck 13 and the bolts 24 and channels 25 limit the sliding movement of the collar l4 relative to the chuck.

Referring now to Figs. 2; and 3 especially, it will be apparent that the vertically extending I-bearn 18 has a horizontally disposed channel section 26 securely attached thereto by conventional channel sections 27, and nut and bolt fasteners 23. A pair of vertically extending L- shaped channel sections 29 are secured in spaced-apart relationship on section 26 by bolts 30. Adjacent the top of each section 2& there is rigidly secured a horizontally extending shaft 31 having a cam follower 32, which preerably comprises a roller, rotatably mounted thereon. In between each section 29 there is located a stop 33, preferably comprising a roller or pin having a reduced portion in the form of a boltwhich is securely held in section 26 by a nut 34. As illustrated in Fig. 3, the cam followers 32 are positioned so that they make rolling contact with the rear radial surface 35 of collar 14 when the latter is in the closed position. The followers 32 are preferably made of bronze to reduce wear on steel surface 35 and to make the rotation of collar 14 as smooth. as possible. The stop 33, although positioned the same distance away from radial surface 35 as followers 32, is made slightly smaller so that there will be no contact between it and surface 35 until the collar 14 slides a short distance from the closed position towards the open position. The purpose of so constructing stop 33 will be explained below.

The periphery 36 of collar 14 is provided with a pair of diametrically opposed cams 37 which cooperate with cam followers 32 for sliding the collar to open and close chuck 13. Each cam 37 extends axially through the periphery 36 of collar 14 and preferably comprises a pair of cam Ways 38 diverging in the form of a V from the front radial surface 39 of collar '14 towards its rear radial surface 35. The cam Ways 38 are so proportioned that when the collar is in the open position, as shown in 38. On reference to Figs. 3, 4 and 5, it will be noted that the diverging V-shaped cam ways 38 are cut into the periphery of collar 14 on a helix angle A, the helix having an axial pitch so proportioned that the periphery of the roller cam follower 32 maintains line contact with the appropriate cam ways 38 as the collar 14 rotates with chuck 13 and slides relative to the chuck, to and from the open and closed positions.

For example, let the collar 14 comprise a machine steel plate having a thickness of 2 inches and an outside diameter of 9% inches. Let the cam follower 32 comprise a bronze roller having an outside diameter of 1%. inches and a thickness of /2 inch. Also, for safe operation, let the collar 14 he slid to and from the open and closed positions upon rotation of the chuck and collar through 30 in either the clockwise or counter-clockwise direction from the rotative position illustrated in Fig. 2. For these conditions, the cam ways 38 would preferably be cut at a helix angle A of 409, the helix having an axial pitch of 26.5 inches. course, subtcnd an arc B of 60 at the widest portion of the V in order to provide for the 30 rotation in either direction, and would be cut to a depth d of inch to insure full, line contact with the peripheries of the cam followers 32.

Collar 14, as shown in Figs. 2 and 3, is also provided with a recess 41 in the form of a slot which extends axially through its periphery 36 and which is located half way between earns 37. It will be noted that slot 41 is not as deep as cam ways 38 so that the roller cam followers 32 will not be disengaged from the rear radial surface 35 of collar 14 as the recess 41 passes adjacent the followers 32 during rotation of the collar 14. However, the collar 14 is located far enough above stop 33,

and recess 41 is deep enough to permit the collar 14 to pass freely over stop 33 when the collar is in the position shown in Fig. 2. Preferably, the diameter of stop 33 is made smaller than that of follower 32 and the recess 41 subtends an angle C which is slightly larger than angle B, so that stop 33 will not contact the walls of slot 41 nor radial surface 35 as the collar 14 slides. This construction prevents any interference with the cooperation between the earns 37 and followers 32 which cause the collar 14 to slide from the open position of Fig. 4 to the closed position of Fig. 5, as the chuck 13 and collar 14 rotate from the position of Fig. 2. Likewise, the stop 33 and slot 41 permit the collar 14 to slide freely to the open position shown in Figs. 2 and 4, when it is desired to remove core bar 11 from the chuck 13.

For the particular embodiment described in the above noted example, it has been found that a recess depth s of *5 inch, a to 1 diameter for stop 33, and an angle C of 70 produce satisfactory results. Obviously, the peripheral recess 41 may take the form of a V-shaped cam way similar to cam ways 38, if so desired. As a practical matter though, this is not necessary and thus cost considerations make the more simple slot form preferable.

The operation of the invention will now be described with particular reference to Figs. 2, 3, 4 and 5. Assuming that the chuck 13 and collar 14 are in the predetermined rotative position illustrated in Fig. 2 and that the collar has been slid to the position of Fig. 4, wherein the chuck is completely open; the core bar 11 carrying roll may then be lowered into the upright U-shaped slot 22 of the chuck. It will be observed that slot 22 only extends about half way through the thickness of chuck 14, at which point the chuck is provided with a shoulder 42 having a front wall 43 and a top wall 44 which extends to a thin boss 45 in the chuck. The square end of the core bar 11 projects far enough into the slot 22 so that it is sufiiciently supported by the chuck; however, when only one safety mechanism 12 is used, a sufficient clearance is left between core bar 11 and wall 43 so that The cam ways 38 would, of

4 i one end of the core bar may be first inserted in a fixed square socket chuck by tilting the bar on its axis, the other end being lowered in an arcuate path into the open chuck 13. When two safety mechanisms 12 are used, as shown in Fig. 1, the bar 11 may be made long enough so that its ends closely abut walls 43 and the core bar will then be lowered into the chucks 13 in a substantially horizontal position, as illustrated in Fig. 4. The collar 14, in the open position, is out of the path of movement of the core bar 11, and the depending lug 23 thereon slidably engages the top wall 44 of shoulder 42 and abuts the boss 45 in chuck 13. The boss 45 assists the bolts 24 and channels 25 in limiting the movement of collar 14 and in preventing the collar from cocking or canting as it slides to the open position.

After the core bar 11 is positioned in slot 22, the chuck 13 and collar 14 may be rotated by a suitable motor (not shown) connected to the shaft 16 of chuck 13 by a conventional drive mechanism (also not shown). As soon as this rotation begins, the roller cam followers 32 bear against two of the diametrically opposed cam ways 38 of cams 37 and urge the collar 14 to the closed position, shown in Fig. 5. As the collar 14 rotates and slides in this manner, recess 41 will freely pass over stop 33 and thus the collar will be permitted to completely close chuck 13 upon a 30 rotation in either the clockwise or counterclockwise direction.

As the chuck 13 and collar 14 continue to rotate, the cam followers 32, having moved out of cam ways 38, will make rolling contact with the rear radial surface 35 of collar 14. Thus, the diametrically opposed followers 32 will provide a balanced force on each side of radial surface 35 to maintain the collar 14 in the closed position. However, as the collar approaches within 30 of the rotative position opposite to that shown in Fig. 2, the followers 32 will be adjacent cams 37 once again. If sufiicient force is now applied to slide collar 14 back to the open position of Fig. 4, it would be possible to open chuck 13, and the bar 11 and roll 10 could fall because the U-shaped slot 22 of the chuck would open downwardly. As a practical matter this would seldom occur during actual rotation of the mechanism 12 because the weight of the core bar 11 and roll 10 hearing on lug 23 of collar 14 would substantially increase the frictional resistance to sliding movement of the collar relative to the core bar 11 and chuck 13. Even if this resistance were overcome, chuck 13 would only be completely open for a fraction of an instant whereupon cam followers 32 would immediately force collar 14 towards the closed position. Nevertheless, the mechanism might jam and be seriously damaged. More likely, the operator might accidently stop the mechanism with chuck 13 upside down and then exert sufficient force to slide the collar 14 to the open position, thereby permitting bar 10 and roll 11 to fall, resulting in injury to himself or others nearby, as well as damage to the apparatus.

In order to eliminate this possibility, it might be suggested that only one cam 37 and one follower 32 be employed so that the collar 14 could only slide to the open position when the slot 22 of chuck 13 was in the upright position of Fig. 2. This is not feasible, however, because the follower 32, during engagement with cam 37 and radial surface 35, would be applying an unbalanced force on collar 14 causing it to cant and bind against chuck 13. This would not only interfere with the free rotation of chuck 13 and collar 14, and the sliding of the collar relative to the chuck, but would also place undue strain upon follower 32, shaft 31, and section 29. These undesirable forces would result in rapid wear of the various contacting parts and eventually lead to their failure.

A successful solution to this problem has been found by inter-posing the stop 33 between sections 29 and by cutting the peripheral slot 41 in collar 14, as noted above. Referring once again to Figs. 2, 4 and 5, as the chuck 13 and collar 14 rotate from the positionof Fig. 2, andthe followers 32 slide collar 14 from the open position of Fig. 4 to the closed position of --Fig. 5 the slot 4-1 passes freely over stop 32. As the collar :14 continues to rotate, the followers 32 make rolling contact with radial surface 35; however, the diameter of stop 33 is-sl-ightly less than that of the follower 32 sothat a-small clearance exists between the stop and radial surface 35 (see Figs. 3 and 5). This construction permits the followers 32' to apply a balanced force on each side of radial surface 35 for maintaining collar 14 in the closed position.

The most important function of stop 33, however, is to prevent the collar 14 from sliding to the open position when the chuck 13 is upside down. As collar 14 approaches the position 180 opposite to that of Fig. 2 slot 41 will be at the top of the collar, and even though followers 32 may engage earns 37, the chuck 13-cannot be opened because stop '33 will bear against radialsurface 35 as soon as collar 14 begins to slide back towards the open position.

Thus, the followers 32 and stop 33 maintain collar 14 in the closed position by engaging radial surface '35, and in so doing, prevent the collar 14 fromsliding to the open position at all rotative positionsotherthanthe one shown in Fig. 2, whether the mechanism is rotating or not. Even though it is possible for the chuck 13 to be opened in this latter positionno harm will result because the core bar 11 is adequately supported by U-shaped slot 22 in chuck 13, and upon 30 rotation in either direction the collar 14 will once again completely close the chuck, whereby the core bar 11 will be prevented from falling out of the chuck.

It will now be seen that the self-closing safety mechanism 12 of the present invention has the following advantages. First, the manual closing of the collar, which.

is necessary when a spring loaded pin is used, has been completely eliminated because the collar 14 is automatically closed as soon as the mechanism begins to rotate. Secondly, the safety mechanism of this invention is so constructed that it can only be opened in one rotative position whether the mechanism is rotating or stationary. These two advantages result in a third, namely, that the core bar 11 carrying roll cannot possibly fall out of the chuck at any time, and thus accidental injury to personnel or damage to property has been substantially eliminated.

While this invention has been shown and described in a preferred form it is to be understood that various changes and modifications may be made therein by those skilled in the art without departing from the spirit of the invention as defined in the appended claims. For example, this invention is not limited to the precise materials or sizes and shapes of its various components, as specified above, nor is its use restricted to retaining square ended core bars for fabric carrying rolls. On the contrary, it has application to any apparatus wherein it is desired that rotatable members of varying sizes and shapes be removably yet safely secured.

Having thus described our invention, what we claim and desire to protect by Letters Patent is:

l. A self-closing safety mechanism for releasably retaining a rotatable member comprising a support, a chuck rotatably mounted on said support, a collar mounted on said chuck for rotation therewith and slidable thereon between positions at which the chuck is open or closed, means on said collar cooperating with means on said support for automatically moving said collar from the open position to the closed positionupon rotation thereof and for maintaining said collar in the closed position.

2. A self-closing safety mechanism for releasably retaining a rotatable member comprising a support, a chuck rotatably mounted on said support, a collar mounted on said chuck for rotation therewith and slidable thereon between positions at which the chuck is open or closed, means on said collar cooperating with means on said support for automatically moving said collar from the open position tothe closed position upon rotation thereof from a predetermined rotative position and for preventing said collar from moving to the open position at all other rota tive positions.

3. A self-closing safety mechanism for releasably re.- taining ,a rotatable member comprising a support, -a chuck rotatably mounted on said support,'a collar mounted on said chuck for rotation therewith and slidable thereon between positions at which the chuck is open or closed, means on said collar cooperating with means on said-support for automatically moving said collar from the open position to the closed position upon rotation thereof from a predetermined rotative position and for preventing said collar from moving to the open position at all other rotative positions except one, means on said collar.coop.- crating with means on said support for preventing said collar from moving to the open position at-said one rotative position.

4. A self-closing safety mechanism for releasably retaining a rotatable member comprising a support, a chuck rotatably mounted on said support, a collar mounted .on said chuck for rotation therewith and slidable thereon between positions at which the chuck is open or closed, means on said collar cooperating with means on said .support for automatically movingsaidcollar from the open position to the.closed position upon rotation thereof from a predetermined rotative position and for preventing said collar from moving to the open position at all other rotative positions except one, means on said collar cooperating with means on said support for preventing said collar from moving to the open position at said one rotative position and for permitting said collar to move to the open position at said predetermined rotative position.

5. A self-closing safety mechanism for releasably retaining a rotatable member comprising a support, a chuck rotatably mounted on said support, a collar mounted on said chuck for rotation therewith and slidable thereon between positions at which the chuck is open or closed, first means on said collar cooperating with first means on said support for automatically moving said collar from the open position to the closed position upon rotation thereof from a predetermined rotative position, said first means on said collar and second means on said collar cooperating with said first means on said support for preventing said collar from moving to the open position at all other rotative positions except one, said second means on said collar cooperating with second means on said support for preventing movement of said collar to the open position at said one rotative position, and third means on said collar cooperating with said second means on said support for permitting movement of said collar to the open position at said predetermined rotative position.

6. The mechanism of claim 5 wherein said first means on said support comprise cam followers, said first and second means on said collar comprise cams and a radial surface respectively.

7. The mechanism of claim 5 wherein said second means on said support comprises a stop, said second and third means on said collar comprise a radial surface and a peripheral recess respectively.

8. The mechanism of claim 5 wherein said first and second means on said support comprise cam followers and a stop respectively, said first, second and third means on said collar comprise cams, a radial surface, and a peripheral recess respectively.

9. A self-closing safety mechanism for releasably retaining a rotatable member comprising a support, a chuck rotatably mounted on said support, a collar mounted on said chuck for rotation therewith and slidable thereon between positions at which said chuck is open or closed, a pair of axially extending cam ways in the periphery of said collar engageable with a pair of roller cam followers mounted on said support for moving said collar from the open position to the closed position upon rotation thereof from a predetermined rotative position, said cam ways and a radial surface on said collar engageable with said cam followers for preventing said collar from moving to the open position at all other rotative positions except the one opposite said predetermined rotative position, said radial surface cooperating with means on said support for preventing movement of said collar to the open position at said opposite rotative position, and means on said collar cooperating with said means on said support for permitting movement of said collar to the open position at said predetermined rotative position.

10. A self-closing safety mechanism for releasably retaining a rotatable member comprising a support, a chuck rotatably mounted on said support, a collar mounted on said chuck for rotation therewith and slidable thereon between positions at which said chuck is open or closed, means on said collar cooperating with means on said support for moving said collar to the closed position upon rotation thereof from a predetermined rotative position, said means on said collar and a radial surface on said collar cooperating with said means on said support for preventing said collar from moving to the open position at all other rotative positions except the one opposite said predetermined rotative position, said radial surface engageable with a stop mounted on said support for preventing movement of said collar to the open position at said opposite rotative position, and a peripheral recess in said collar circumferentially spaced from said means on said collar and movable relative to said stop for permitting said collar to move to the open position at said predetermined rotative position.

11. A self-closing safety mechanism for releasably retaining a rotatable member comprising a support, a chuck rotatably mounted on said support, a collar mounted on said chuck for rotation therewith and slidable thereon between positions at which said chuck is open or closed, a pair of axially extending cam ways located in diametrically opposed relationship in the periphery of said collar and engageable with a pair of roller cam followers mounted on said support for moving said collar from the open position to the closed position upon rotation thereof from a predetermined rotative position, said cam ways and a radial surface on said collar engageable with said cam followers for preventing said collar from moving to the open position at all other rotative positions except the one opposite said predetermined rotative position, said radial surface engageable with a stop mounted on said support between said cam followers for preventing move ment of said collar to the open position at said opposite rotative position and a peripheral recess in said collar circumferentially spaced between said cam ways and movable relative to said stop for permitting said collar to move to the open position at said predetermined rotative position.

No references cited.

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