US223730A - harvey - Google Patents

Description

4 Sheets-Sheet 1. H. APHARVE Y- Machine for Rolling Threads ofSbrew's or Bolts.

No. 223,730. Patented ranqzo, 1880.

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4 sheets -sflet H. A HAQRVEY. Machine for Rolling Threads of Screw-s or Bolts.

- No. 223,730. Patented Jan. 20, 1880..

Rmamss NPEYERS, PHOYO-UTHOGRIPNER. WASHINGTON. 0 CV 4 Sheets-Sheet, 3.

. H. A. HARVEY. Machine for RollingThreads of Screws OLBOPBS/V Patented Jan. 20, -1880.

EQ W N. PETERS, FNOTOUTNO GRAP 4 sums-sheep 4. H. A. HARV EY. Machine for RollingThreads of Screws or Bolts.

No. 223,730. Pat ented Jan. 20, 1880.

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UNITED STATES PATENT OFFICE.

HAYWARD A. HARVEY, OF ORANGE, NEW JERSEY.

MACHINE FO'R ROLLING THREADS OF SCREWS-OR BOLT S.

SPECIFICATION forming part of Letters Patent No. 223,730, dated January 20, 1880;

' Application filed October 15, 1879.

To all whom it may concern Be it .known that I, HAYWARD A. HARVEY, of Orange, New Jersey, have invented certain Improvements in Machines for Rolling the Threads of Screws or Bolts, of which the following is a specification.

My improvements relate to apparatus for forming the threads of screws or bolts by the combined action of a curved stationary die and a cylindrical rotating die upon a blank introduced between the dies and rolled along the face of the stationary die by the friction of the rotating die.

In dies of this kind the-screw-threads have been heretofore impressed upon the body of the blank by parallel ridges of metal formed upon the faces of the dies at the proper angle of inclination with the plane of motion of the rolling-die.

My invention consists, first, in transversely notching at intervals the parallel ridges on thefaces of the dies, so that they may present aseries of sharp points or corners which will have a cutting action upon the blank, such removal of a portion of the metal from the blank being the result of the differential action upon the blank of the notched edges and the sides and bottoms of the grooves formed in the working-faces of the dies, and thereby operate to effectthe formation of the thread partly by displacing -or upsetting the metal and partly by the actual removal of a portion of themetal from the blank.

The second part of the invention consists in the combination, with each other, of two or more pairs of dies, the first pair of dies being so organized as to form a comparatively shallowgroove in the path of the thread around the shank of the blank, and the next pair of dies being so organized as to make such groove deeper, either to the extent of finishing the thread or of partially finishing it, preparatory to subjecting the blank to the action of a third pair of dies, and so on until a thread of the desired depth is formed.

In carrying out myinvention I may arrange successive pairs of dies in close proximity and feed the blank directly from onepair of dies to the next pair, or I may introduce between the pairs of dies a rotating transfer-wheel, acting in conjunction with a concave guidewall, for carrying the blank fromthe pair of dies in which it is first operated upon to the pair of dies which next act upon it. In either event the combination with each other of the successive pairs of dies, or of the successive pairs of dies andthe intermediate transfer mechanism, is such that the blank, after having been operated upon by one pair of dies, is so presented that the ridges in the next fol: lowing pair of dies will engage the spiral groovealready formed upon the periphery of the blank. v

The accompanying drawings, which illustrate a machine embodying my invention, and

also embodying several other inventions which I am about to make the subject of a separate application for a patent,are as follows: Figure 1 is a front elevation, showingthe ex posed portions of the faces of two rolling-dies mounted in suitable bearings and geared to a central shaft carrying the intermediate transfer-wheel, the two systems of dies and the transfer-wheel being arranged in the same plane. Fig. 2 is an end elevation of themachine, affording a side view of a hopper for carrying a mass of blanks, and ways in which I the blanks are conducted from the hopper to the tube, from which they are permitted to drop into a recess at the end of the stationary die. Fig. 3 is a transverse section through the machine on the line as a: on Fig. 1', exhibit ing in section the shafting upon which the dies and the transfer-wheel are mounted, and also showing an. oscillating pusher, which pushes the blanks sidewise successively into the space between the-first pair of dies. Fig. 4 is a view, in detail, of the pusher and the oscillating arm upon which it is mounted, showing I the tripping-pawl which is affixed to the oscillating arm of theylever, and which, after having been caught by a pin onthe face of I the die and moved a prescribed distance, is

tripped from the pin, and thereby permits the oscillating arm to spring back to its normal position. Fig. 5 is a section,on an enlarged scale, through the line y 3 on Fig. 3, showing the shape of the working-faces of the first pair of dies. Fig. 6 is a similar section through the line 3 g on Fig. 3, sbewing the shape of the working-faces of the second pair of dies. Fig. 7 is a section through the linezz on Fig.

3, showing a milling-wheel for cutting the cone-point upon a screw which is being operated upon by the second pair of dies. Fig.

8 is a view, on a still larger scale, of the working-face of one of the dies, showing the transverse notching of the parallel ridges formed in the face thereof. Fig. 9 is a transverse vertical section through the central portion of the hopper and through the lifter, by means of which the blanks in the hopper are caught by the head and lifted so that they fall by. gravity into the ways which conduct them to the check.

The various parts of themachine are Inountwith the curved stationary die I), and the transfer-Wheel 0 acts in conjunction with the curved guide-wall 0, while the secondary die cl acts in conjunction with the curved stationary die d.

The shaft B is provided on its lower end witha cam or eccentric, B, which imparts a reciprocating motion to the cam-bar B The cam-bar B is provided at the end with a transverse pin, B which is inserted in the forked arm of the bell-crank lever B By reason of this connection the bell-crank lever is caused to oscillate by the movement of the cam-bar B and this oscillating motion is transmitted, by means of the pitman B to the lifter E.

The lifter is composed of two parallel plates, 0 e, of segmental form, which are arranged at the desired distance from each other, and are fastened together and pivoted to the upper end of the ways 0. The two parallel plates of the lifter are in line, respectively, with the two parallel plates of the ways, and reciprocate in a vertical path in the center of the hopper E. The bottom of this hopper is slotted to allow the movement of the lifter, and the range of movement of the lifter is such that the upper edges of the two parallel plates 0 6 drop from the position in which they are shown in Fig. 2 to a point slightly below the mouth of the opening in the bottom of the hopper, as

shown in Fig. 9.

Blanks are thrown indiscriminately into the hopper, which has, it will be seen, converging side walls. point, the blanks are permitted to drop into the opening in the bottom of the hopper, and are caught between the parallel plates of the lifter, and when the lifter rises hang therein by their heads, and slide therefrom by gravity into the ways.

is shown in Fig. 3.

When the lifter falls to its lowest Hoppers and lifters of this character are well known.

At the bottom of the ways there is the usual reciprocating gate or check, F, which is thrust outward by the cam f on the shaft B, and is returned to its normal position, as the cam continues its rotation, by the spring f. The gate or check F, in its reciprocating movement, cuts off a blank from the lower end of the row of blanks hung by the heads in the ways, and permits it to drop through the short tube or guide f (indicated in dotted lines on Figs. 1 and 2) into the space between the periphery of the rolling-die b and the guide-wall b at the end of the. stationary die b.

The blank is held in a vertical position by the guidewall b the concave end of the pusher g, and the spring g, which is affixed to the pusher and partially embraces the body of the blank.

The pusher g is affixed to a stud on the end of the oscillating arm H, projecting radially from a loose hub, h, on the shaft B, immediately beneath the rotating die I). Loosely hun g on the stud is a tripper, H, in the form of a bell-crank lever, one of the arms of which points toward the hub H, while the other stands at about a right angle with the first,

A pin, h, projecting radially from the hub h, is connected to the end of a spiral spring, [1/2, the opposite end of which is secured to the frame of the machine, and the pull of this spring tends to hold the oscillating arm H in the position in which it The under side of the rotating die I) is provided with a pin, H which, as the die rotates, strikes against the inwardly-turned arm of the tripper H- and carries the oscillating arm H around until the roller on the end of the outer arm of the tripper has traveled to the end of the concentric part of the guide H at which point the tripper is free to turn on its axis, and hence releases itself from the pin H while in obedience to the action of the spiral spring h the arm H moves back to its normal position.

In the act of moving forward, however, the pusher g has delivered the blank caught in the recess G so far into the space between the rotating and stationary dies that the blank is caught by friction androlled forward around the face of the stationary die.

The dies b and b, by a continued graving and compressing action upon the periphery of the blank, produce a shallow groove upon it in a spiral path corresponding to the path of the screw-thread.

Having traveled to the opposite end of the stationary die I), the blank is delivered to and caught by the transfer-wheel c, which rolls it around the guide-wall c and delivers it to the secondary rolling-die d and stationary die d. In passing through the secondary dies the shallow groove upon the periphery of the blank one of the rolling-dies.

point on the end of the screw.

produced by the primary dies, which is represented approximately in Fig. 5, is deepened, so that the central longitudinal section of the screw presents an approximation to the appearance indicated in Fig. 6. V

In some cases Imayomit the transfer-wheel and substitute in its place the secondary dies, delivering from the primary dies directly to the secondary dies, which, except as to their size, would be represented by the transferwheel 0 and the stationary guide-wall c.

In the case of large screws, especially woodscrews in which a deep thread isrequired, I may increase the number of pairs of dies in the series, employing each successive pair of dies to deepen the groove made by the next preceding pair of dies until the thread is finished to the proper depth.

I have shown in connection with my secondary dies a milling-wheel for cutting a cone- This millingwheel I, which is a well-known device, has, it will be seen, a beveled cutting-edge, and is affixed to a pulley, i, loosely mounted upon the hollow cylinder 1, through which the shaftD passes, and is driven by the belt 01, which is carried by means of leaders to the pulley i on the driving-shaft A of the machine.

The milling-wheel, which is driven at a higher speed than the rolling-die d, rotates upon an axis which is parallel with, but slightly dis- .tant from, the axis of the die d, so that its work on the point of the screw will be progressively done, and also so that the edge of the millingwheel will not project beyond the periphery of the rolling-die at the place where the blank is delivered to the rolling-die.

In certain cases where only a shallow thread is required, only one pair of my notched dies may be necessary, and in such a case, as indeed in all other cases, the primary rolling-die may be provided with a milling-wheel.

In the case of very large screws it may be desirable tb divide the work of cutting the conical point by providing milling-wheels for each It will be seen that the transfer-wheel c and its guide-wall 0 may be omitted and some other transfer device be substituted therefor. If, however, the transfer-wheel is employed, it

versely notched at intervals, substantially as i and for the purpose described. a

2. 1n machines for forming screw-threads, jointly, two or more pairs of dies, each pair consisting of a rotating die and a stationary curved die, the respective pairs of dies having the ridges on their working-faces relatively varying in depth or width, for the purpose of forming the thread of a screw or bolt by a series of two or more progressive operations, the primary dies forming a shallow spiral groove upon the body of the blank,-and the subsequently following pair or pairs of dies succes sively deepening and enlarging such groove until the thread is finished,substantially as described.

3. The combination of pairs of dies, substantially such as described, with transferring mechanism for conveying the blanks from one pair of dies to the next following pair of dies, consisting of the wheel 0 and the guide a, substantially such as described.

4. The oscillating arm H, connected with the spring k and provided with the tripper H, in combination with the stationaryguide H and with the actuating-pin H all arranged and operating substantially as and for the purpose set forth. I

5. The hollow cylinder I, affording upon its exterior the bearing for the milling-wheel I, in combination with the shaft D, extending eccentrically through the hollow cylinder I, and carrying the rotating die d, substantially as shown and described.

H. A. HARVEY.

Witnesses M. L. ADAMS, Enwn. PAYSON.

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