US583688A - Expansion-cam - Google Patents

Description

(No Model) 0. P'. LAWRENCE.

EXPANSION 0AM. No. 583,688. Patented June 1,1897.

Z 5 JCT/670609" UNTTED STATES PATENT EEICE.

CHARLES P. LAIVRENCE, NORWVAY, MAINE.

EXPANSION-CAM.

SPECIFICATION forming part of Letters Patent No. 583,688, dated June 1, 1897. Application filed February 7, 1895. Serial No. 537,574. (No model.)

To aZZ whom it may con/acre.

Be it known that I, CHARLES P. LAWRENCE, of Norway, county of Oxford, State of Maine, have invented an Improvement in Expansion- Cams, of which the following description, in connection with the accompanying drawings, is a specification, like letters and figures on the drawings representing like parts.

This invention has for its object to provide a novel cam capable of expansion by the operator for the purpose of varying its throw as necessity may require. In many machinessuch, for example, as lasting or pulling-over machines, where the lasting operation or the operation of the nippers which act upon the leatheris controlled by a cam-there has heretofore to my knowledge been no means for varying the action of the lasting devices or nippers for' pulling over or stretching the leather to a greater or less extent according to its weight or condition.

By the use of an expansion-cam embodying my invention, if it is found that the usual throw of the cam is insufficient to properly stretch or pull over the leather, the operator by a simple movement may vary the throw of the cam to increase or magnify its action.

In the drawings I have illustrated my invention in connection with a detail of a lasting-machine, Figure 1 showing in front elevation my invention in operative position. Fig. 2 is an enlarged side elevation of the cam, partly broken away, the operating-wedge being omitted. Fig. 3 is a central vertical section taken on the line 3 3 of Fig. 2.

Referring to the drawings, while I have illustrated my invention as used in connection with a lasting-machine, yet it should be understood that my invention is not limited as to its use to any particular machines or class of machines.

The cam is composed of a body H and two side plates H H the body having an adjustable throw point or block H adapted to slide radially between the side plates referred to and provided with a dovetailed groove, which is entered by the corresponding dovetailed Wedge H shown as rigidly connected with a groove-collar H splined on the main shaft A and rotatable therewith, but having an back and forth as required on the shaft A a bracket 6 being shown supporting a roll e to be operated by the cam, the roll e being held against the cam by the usual spring (not shown) in the spring-barrel 6 In use the cam is positively operated by reciprocating the collar II on the main shaft, the wedge H then sliding back and forth in the dovetailed groove of the throw-block transversely of the cam. This serves to expand and contract the cam, the cam-surface thereof changing in shape correspondingly, within the two extreme positions shown in Fig. 3 by full and dotted lines.

While such a cam is particularly useful in lasting and pulling-over machines, yet its use is not limited in this respect, for it may be applied to any kind of machine where a variable cam movement is desired.

Having described one form of my invention, what I claim, and desire to secure by Letters Patent, is

1. An expansion-cam, having a movable throw-block carried thereby as a constituent part thereof, combined with a wedge carried by said cam, and interlocked with the throwblock, interlocking means being provided therefor on the wedge and throw-block and means to move said wedge to vary the position of the throw-block, substantially as described.

2. An expansion-cam, havingathrow member movable therein and provided at its inner end with a dovetailed edge, a grooved collar,

and its attached dovetailed wedge, cooperating with and to positively vary the position of the said throw member out and in rela tively to the remaining cam-surface of the cam, substantially as described.

3. A cam-body, having a throw member forming a constituent part thereof, said throw member being movable relatively thereto in a radial direction, whereby said cam may be expanded or contracted and the cam-surface thereof changed in shape, and a Wedge inovname to this specification in the presence of ing parallel to the axis of the said cam-body, two subscribing Witnesses.

said wedge having means whereby the same 1 j i j r 9 1 E. 1s movably connected to said throw member CHAhLES 1 RI AU to positively move the same in and out, snb- \Vitnesses:

stantially as described. HOWARD D. SMITH,

In testimony whereof I have signed my M. P. SMITH.

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