US652763A - Expansible pulley. - Google Patents

Description

ubfsszgss. Patented m 3, I900. B. B. FARNHAM.,

EXPANSIBLE PULLEY.

(Appliqation filed May 4, 1900.)

UNITED STATES BION B. FARNHAM, OF NEW YORK, N. Y.

EXPANSIBLE PU LLEY.

SPECIFICATION forming part of Letters Patent No. 652,763, dated July 3, 1900.

Application filed May 4, 1900.

To all whom it may concern:

Be it known that I, BION B. FARNHAM,a citizen of the United States,residing at New York,

(Oastleton,) in the State of New York, have invented certain new and useful Improvementsin Expansible Pulleys; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification. I

This invention relates to expansible pulleys; and my invention is so arranged as to render the expansion and contraction thereof easy and rapid. r

In the drawings, Figure 1 shows a longitudinal sectionalviewof mypulley in operative construction; Fig. 2, an elevation of the retaining-plate; Fig. 3, an elevation of the eX- pansion plate; Fig. 4, an elevation of the clamping-plate, and Fig. 5 an end view of the cap revolubly set upon one of the ends of the shafting; Fig. 6, a sectional elevation of one side of my pulley,en1arged to clearly show the parts. 7

The numeral 1 indicates a tubular shaft having openings 2 through its walls in order that the parts occupying the interior may be seen and easily arranged and repaired. In the shaft 1 I preferably set circular blocks 3, with openings in them and arranged to act as boxes to support and in which the rods 6 and 7 may rotate. While I prefer this method of making the rods 6 and 7 rotatable, I do not confine myself thereto, as any other method may be used that may be desired. The rods 6 and 7 are prevented from having an endwise thrust preferably by means of washers 17, but any other means may be used. The rods 6 and 7 are each threaded right and left 'i. 6., that portion of rod 6 restingin the tubular shaft to the left of the central block is threaded left hand, as at 6, and that portion thereof resting in the shaft to the right of said block is threaded right hand, as at 6, while that portion of rod 7 resting in the shaft to the left of the central block is threaded right hand, as at 7, while that portion resting in the shaft to the left of said block is threaded left hand, as at 7.

each of said nuts. which pass through the openings 2 in shaft 1,

Serial No. 15,481. (No model.)

Rod 6 will be seen to pass througha nut 11, the rod-threading meshing with appropriate threading in These nuts have shanks precisely as do those shown at 11 on rod 6. ,On the left-hand end of the shaft 1 is revolublyset a cap 4, with an opening in its outer end and having the circular edge of the opening toothed, as seen at 5 in Fig. 5. Through on each rod is set a small gear 8 and 9, ar-

Yranged to be moved lengthwise on theshafts,

so as to be thrown in and out of gear when desired, and to prevent their being revoluble v on the rods they are fitted to slide over a feather 10, which is shown onlyon rod 6, that on rod 7 being on the rear side of the rod. Both these small gear mesh with teeth 5 on the revoluble cap4 when they mesh with each other; but when either of them is slid outward on its respective rod, as is gear 8 on rod '6, then but one of them (gear 9) meshes with teeth 5. This is arranged so that when it is desirable to move clamping-plate l2 independent of the spreading-plate 13 it may be done, which allows of making plate 12 fully and completely clamp arms 15 in secure position. Clamping-plate 12 has slots 12 and is fixed upon the shaftl to slide laterally thereon, but not to rotate on the shaft. Spreading-plate 13 is likewise fixed upon the shaft 1 and is preferably a solid plate having a beveled edge. Retaining-plates 14 are immovably affixed to the shaft and have slots 13, and between retaining-pl ates 14 rests the segmental pulley-block 16, each of the segments thereof having a downwardly-sloping arm 15, which passes through one ofthe slots 513?, rests on the beveled edge of spreading-plate 13, and passes through one of the slots 'l2 in clamping plate 12.

The operation is as follows: Gear 8 being slid along the rod 6 until it meshes with teeth 5 on cap 4 and with the gear 9 and the cap 4 being turned or rotated in one direction this opening both of the rods protrude, and

clamping-plates 12 and spreading-plates 13 will move outward from retaining-plates 14, and as arms 15 slide over or upon the beveled edge of spreading-plates 13 segments 16 will be compelled to rise between plates 14 and increase the diameter of the segmental pulley. \Vhen cap 4 is turned oppositely, clamping-plates 12 and spreading-plates 13 will approach retaining-plates 14 and the segments l6 will fall between plates 14 and decrease the diameter of the pulley. When it is desired to operate clamping-plate 12 alone, gear 8 is left to mesh with teeth 5 on cap 4, while gear 9 is thrown out of mesh by sliding it along the rod 7, and by reversing the positions of the gears S and 9 the spreading-plate 13 may be moved without moving plate 12. It will be evident to those skilled in the art that plate 12 may be moved in other ways and by other means than I have shown, and I show the way seen in the drawings only as my preferred method, while I do not confine myself thereto.

lVhile I have not shown any particular manner of rotating cap 4 except by handpower, it may be made to rotate by means of a belt passed around cap 4 or by gearing it to a power-operated shaft or otherwise, as the circumstances may demand. By forming sprockets on its periphery and passing a suitable chain over it, so as to operate with said sprockets, the chain forming a chain belt,

the cap 4 may be operated by drawing on the chain. I have used this method in some cases and find it to operate well. By use of clamping plate 12 with its inwardly projecting and angular flange I am enabled to do away with all set-screws and gibs, such as were shown and described in my patent dated July 10, 1894, and numbered 522,658, and I am enabled to make a much better and secure clamp upon the arms 15, and by use of the two threaded rods 6 and 7 inside the tubular shaft and arranged practically as shown I am enabled to better and easier operate the spreading and clamping plates, and therein said shaft, the spreading and clamping plates I arranged to be thrust lengthwise on said shaft, and a plurality of threaded rods inside said shaft, the threading being arranged to move nuts outwardly and inwardly on said shaft in unison, said nuts being fixed respectively to the clamping-plates and to the spreading-plates, the rods having means whereby they may be revolved irrespective of the revolutions of the shaft substantially as described.

2. In a segmental expansible pulley having projecting arms connected to the segments, a tubular shaft, and spreading-plates, clamping plates and retaining plates arranged upon the shaft, the spreading and the clamping plates being arranged to have lateral thrust along the shaft, and a plurality of threaded rods in said tubular shaft and nuts on said rods, some of said nuts being afiixed to the spreading-plates and their threads meshing with the threads on one of the rods, and other of said nuts being affixed to the clamping-plates and their threads meshing with those on the other rod in order that the said spreading and the clamping plates may be moved laterally along said tubular shaft and clamp the arms of the segments, and means whereby the threaded rods may be rotated separately or collectively, all combined substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

BION l3. FARNHAM.

Witnesses:

W. J. Honor-r, W. M. BROWN.

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