US251874A

US251874A - Machine for rolling th reads of screws or bolts

Info

Publication number: US251874A
Authority: US
Publication date: 1882-01-03
Anticipated expiration: 1899-01-03

Description

(No Model.)

H. A. HARVEY.

MACHINE FOR ROLLING THREADS OF SQREWS 0R BOLTS:

N 25;1,874. g Patented Jan. 3,1882.

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UNITED STATES PATENT Grates.

HAYWARD A. HARVEY, OFORANGE, NEW JERSEY.

MACHINE FOR ROLLING-THREADS 'OF SCREWS OR BOLTS.

SPECIFICATION forming part of Letters Patent No. 251,874, dated January 3, 1882.

' Application filed August 22, 1881. (No model.)

To all whom it may concern:

Be it known that I, HAYWARD A. HARVEY,

ofOrange, in the county of Essex and State of New Jersey, have invented a new Improvement in Machines for Rollin g Threads of Screws or Bolts; and I do hereby declare the following, when taken in connection with the accompanying drawings and the letters ofreference marked thereon, tobe a full, clear, and exact description of .the same, and which said drawings constitute part of this specification, and represent, in-

Figure 1, a front view; Fig. 2, aplan or top "iew; Fig. 3, the disk detached; Fig. 4:, a section of the die, disk, and fork enlarged. A My invention relates to an improvement in machines for threading screws or bolts, particularly to that class in which the thread is produced by the combined action of a curved stationary die and a cylindrical rotating die upon the blank introduced between the said dies and rolled along the face of the stationary die by the friction of the rotating die, the faces of thetwo dies provided with parallel ribs inclined to the plane of revolution of the rotating die, so thatthe blank rotated between them has impressed upon its body ascrewthreadfcorresponding to the inclined ribs on the rotating and stationary dies, with special reference to the machine for which Letters Patent ofthe United States were granted to me, dated January 20, 1880, No. 223,730. In

' that patent one part of my invention consisted in combining two or more pairs of (lies arranged so that the first pair will form comparatively shallow spiral grooves on the surface of the blank. The next pair, to which the,

blank is transferred from the first,will deepen that groove, (and may be finish it or, if other pairs are to be employed, it istransferred from one pair to the next, each successive pair deepening the groove, until finally the last pair of dies completes the thread. l

Mypresent invention relates particularly to mechanism for transferring theblanks from one pair of diesto the next, and has for its object to dispense with the usual checking mechanism-at the feed-channel, and to receive the blanks directly from the channel into the control of the device, which will ultimately transfer the blank from the first pair of dies to the second, whereby not only the proper presentation of the blank to the first pair of dies is insured, but also its deliveryto the second pair of dies after the first shall have performed running close to the mouth of the feed-chan- 6o nel, and constructed with recesses in its edge, so that the blank at the mouth of the channel rides against the periphery of said disk until one of said notches is presented to the mouth of the channeh'when the said blank will be forced into said notch by the pressure of the blanks in rear of it, said notch taking it from its place at the mouth of the channel, and that part of the periphery next in rear of said recess passing over the mouth of the channel as the said recess takes the blank therefrom, and continuing, the second blank following into the second recess, and so on; also, in

forked spring-spindles arranged radially and so as to be revolved in a plane parallel with and concentric. to the revolving die, combined with a cam, stationary or otherwise,which will force the forks successively inward as they approach the mouth of the feed-channel, and from which said forks willescape when opposite 'the'"8o mouth of the feed-channel, so as to spring forward and receive within the fork the blank presented at the mouth of the channel and pass on with the blank, the pressure of the spring on the spindle radially outward tending to bear the blank awayfrom the revolving die,

and so that the blank within the fork, as it passes from between the first pairof dies,will be pressed radiallytoward the secondpair of dies and away from contact with the first revolving o die into contact with the second revolving die, thepressure of the spring serving to force the groove of the blank onto the ribs of the second revolving die, thereby insuring the proper relation and presentation to the second pair 5 of dies for the continuation of the work in producing the thread.

The mechanism for making the groove in the blank is substantially the same as that shown in my patent before referred to. scription of this part of the machine is therefore all that is required.

A brief (16- too A represents the first curved stationary die, and Bits corresponding revolving die, arranged upon a vertical shaft, 0; A, the second stationary curved die, and B the second revolving die, arranged upon a vertical shaft, 0, the said two shafts geared together by pinions D D, power being applied to the shaft 0 through a bevel-pinion (shown in broken lines, Fig. 1) working into a corresponding bevel-gear, D on the shaft 0. I

E is the feed-channel, arranged in an inclined position to receive a column of blanks, the incline being such that gravity alone causes them to gradually slide down the channel, carried by their heads, in a well-known manner for feeding screw-blanks. The revolving and stationary dies have their working surfaces constructed with spiral or inclined parallel ribs, corresponding to the thread to be produced, so that a blank received from the channel and delivered between the first stationary die, A, and revolving die B will be caused to roll or travel along the surface of the stationary curved die by the friction ofthe revolving die and have impressed upon its surface a groove corresponding to the ribs on the said dies, and arriving by such rotation to the end of the first curved die, a second revolving die takes it and in like manner rolls it along between its surface and the correspondinglycurved die and deepens the groove made by the first, and may be finishes the thread.

On the shaft 0 of the first die, or on a hear ing concentric with that die, and above it,1 arrange a disk, F, equal in diameter (or nearly so) to the circle of which the revolving die is a segment, so that the edge of the disk will extend over the space between the revolving and stationary dies. This disk is shown detachedin Fig. 3. In its periphery are recesses a, equidistant from each other. The extreme depth of the said recesses should be substantially the diameter of the blank. Said recesses are formed one side nearly radial, the other inclining gradually outward in the direction of the revolution of the disk until it reaches.

the periphery, as seen in Fig. 3. This disk is arranged so that its periphery travels close to the mouth of the feed-channel, and so that when the unbroken part of the periphery of the disk lies in front of the mouth of the channel it will hold back the column of blanks in the channel; but as it passes on and the inclined side of the recess comes before the channel the lower blank passes inward on said incline until it arrives at the full depth of the recess, at which time it is entirely outside the channel, and so that, the disk passing on, the said recess will take the blank from its position at the mouth of the channel and carry it forward, the periphery of the disk in rear of the blank closing the mouth of the channel, holding back the second or next blank until the next succeeding recess presents itself, when the second blank will be received in like man- Her, and so continuing, the blanks coming down the column will be successively taken by each succeeding recess, the column each time checked by the disk which takes away the blank. Rotative movement is imparted to the disk to cause it so to check the blanks by means of a train of gears, G Gr, the driving-gear fast upon the shaft 0 and the proportion of the gears being relatively such that the requisite rotation shall be imparted to the disk, it being understood that the said disk must revolve'only so fast as the blank travels between the revolving die and the stationary die-that is, aboutone-half the velocity of the revolving die.

To deliver the blanks from'the first pair of dies to the second, I arrange on the disk F spindles d. These spindles are supported so as to be freely movable radially toward and from the center of motion of the disk or die, I

and so as to travel with the'disk-that is, move with the blanks as they travel between the dies. These spindles are each provided with an independent sprin 0, the tendency of which is to force them radially outward. Their extreme outward movement is stopped by a collar,f, coming against a flange or shoulder. on the disk on which-they are supported. Theouter end of each spindle is made in the shape of afork, h, the opening of the fork corresponding to the blank to be threaded. The position of the forks as here represented corresponds to the position of the recesses in the disk-that is, the deepest partof the recess, or point where the blank comes entirely away from the mouth of the channel, and as seen in Fig. 2. As the spindles revolve they are successively forced inward before they arrive in front of the mouth .of the channel. This movement is best made by a stationary cam or incline, n, on that side of the channel toward which the forks move, so that as the forks come upon said incline they are gradually forced inward, and so that the extreme outer end of one side will pass the blank. Then the fork, escaping, will be forced by its springoutward and so as to take within it the blank presented at the mouth of the channel, and continuing its rotative movement,the fork willcarry the blank supported by its head to the space between the revolving and stationary dies, and will continue to engage the blank during its travel between the dies, and

so soon as the blank has passed out from between the revolving and curved diesthe spring upon the fork will force it radially outward, carrying the grooved blank away from the periphery of the revolving die and against the surface of the next revolving die, the ribs-of that die entering the grooves i-ntheblank and following on with the blank until it enters between said-second revolving die and its stationary curved die. dies, it passes out and away from the fork which delivered it, and the fork goes on to receive another blank, as before. The forks thus arranged and supporting the blank by the head prevent any axial movement of the blank and Entering between those-- the same relation that it comes from the first dies, so that the ribs of the second pair of dies are sure to follow the groove made by the ribs of the first dies.

The forked spindles may be used to advantage, in combination with the disk F, as the checking mechanism for the column. In that case the checkingadisk will form the support for the spindles; but other checking mechanism may be employed in combination with the forked spindles, it only being necessary that there shall be some cheekingmechanism which will hold back the column until a fork is presented to receive the blank therefrom.

The disk may be used without the forks to receive the. blanks from the channel, as before described. In that case some other transferssuch, for instance, as that found in my patent before referred tomay be employed. When the forks are used the gearing which imparts a positive rotative movement to them and to the disk may be dispensed with, because the blanks themselves are forced alongthe circular path by the rotation of the revolving die, and they, being within the forks, will necessarily carry the forks with them, so that the blanks themselves may serve to carry the forks and the disk to which they are attached; but in that case, in starting the machine, and when no blanks are between the revolving and stationary die, it will be necessary to start the forks by hand and carry the first blank into its revolving position between the two dies.

If more than two pairs of dies are employed,

like forks may be arranged on the second die,

to successively receive the blanks from the forks of the first pair and in like manner present them to the third pair. In case the forks are not used the disk may be carriedby the blanks in like manner; but in that case the recess which receives the blanks must be of such a shape that the blank can take a bearingin the recess forward, that is simplya notch in width equal to the diameter of the blank. I claim- 1. In machines for rolling the threads of screws or bolts, a pair of dies consisting of a rotating die and a stationary curved die, said dies having ribs on their workingfaces for forming the thread of a screw or bolt upon a blank passing between them, combined with a feed-channel for delivering blanks and a disk arranged above and revolving'in a plane parallel with and concentric to said revolving dies, the peripheryof said disk running close to the mouth of saidchannel, and constructed with recesses to successively receive blanks from said channel and present them to the passage between said revolving and stationary die, substantiall y as described.

2. In amachine for forming screw-threads, two or more pairs of dies, each pair consisting of a revolving die and a stationary curved die, the respective pairs having ribs on their working-faces, the ribs on the one pair varying in depth or width from those on the other pair, for the purpose of forming the thread of a screw or bolt by a series of two or more progressive operations, combined with afeed-channel to present a column of blanks to the first pairof dies, and spring-forks arranged to travel in a plane parallel with the revolving die of the first pair and to pass the mouth of said channel, and also arranged to move radially toward and from their center of motion, and mechanism, substantially such as described, to force said forks inward as they successively approach the mouth of the feed-channel and embrace the blank presented at the mouth of thechannel and travel with the blank in its passage between the dies, until the blank which they hold, passing from the first pair of dies, will be forced from the periphery of the first revolving die into contact with the ribbed surface of the second revolving die, substantially as described- 3. In a machine for forming screw-threads, two or more pairs of dies, each pair consisting of a revolving die and a stationary curved die, the respective pairs of dies having ribs on their working-faces, the ribs on the one pair varying in depth or width from those on the other pair, for the purpose of forming the thread of a screw or bolt by a series of two or more progressive operations, combined with springforks arranged to travel in a plane parallel with the revolving die of one pair, and also to move radially toward and from their center of motion, so that, receiving the blanks, they travel with the same in their passage between the dies until, the blanks which they hold passingfrom the pair of dies which work in conneciion with" said forks, theywill be forced from the periphery of the revolving die of that pair into contact with the revolving die of the next pair, substantially as described.

H. A. HARVEY. Witnesses:

M. L. ADAMS, E. H. WILLIAMS.