US727426A - Bolt-head-milling machine. - Google Patents

Description

No. 727,426. PATENTED MAY 5, 1903-.,y

B. F. PAIST.

BOLT HEAD MILLING MAGHINE.`

APPLmATIoN FILED 00T.2z,v1901.

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'N o. 727,426. l PATENTED` MAY 5, 1903.

B. F. PIST.

- BOLT HEAD MILLING MACHINE.

APPLICATION FILED 0012.22, 1901. No MODEL. s SHEETS-snm z.

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No. 727,426. I PAILNILD MAY 5, 1903.

B. I". PAIST. i BOLT HEAD MILLING MACHINE.

APPLICATION FILED 00T. 22, 1901. NO MODEL. 8 SHEET zcfses@ XE... a.. I I o# No. 727.426. PATLNTLDMAY-, 190s. B. P. PAIST. BOLT HEAD MILLING MACHINE.

APPLICATION FILED 0(`}T.Z2, 1901. N0 MODEL. 8 SHEETS-SHEET 4.

PATENTED MAY 5 1.903.4

B." F. PIIIsT. BOLT HEAD MILLING MACHINE.

APPLICATION FILED 00T. 22, 1901..

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No.- 727,426. PATBNTED MAY 5, 1903.

B. P. PAIST BOLT HEAD MILLING MACHINE.

APPLIoATIoN rlLnnYooT-z, 1901. HOMODBLV,"

PATENTED MAY 5, 1903.

B. F. PAIST. BOLT HEAD MILLING MACHINE.

APPLICATION FILED 001222. 1901. Ifo MODEL. A 52g?? 8 SHEETS-SHEET 7.

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PATENTED MAY 5, 1903..

B. L. PAIST. BOLT HEAD MILLING MACHINE.

APPLICATION FILED 00T.22. 1901.

8 SHEETS-SHEET 8 Unire STATES! Patented May 5, 1903.

BENJAMIN F. PAIST, OF PHILADELPHIA, PENNSYLVANIA.

BOLT-HE'AD-lVllLpLlNG MACHINE.

SPECIFICATION forming part of Letters Patent No. 727,426, dated May 5, 1903.

Application filed October 22,1901. Serial No. 79.596. (No model.)

To all w/wm it may concern,.-

Be it known that I, BENJAMIN F. PAtsT, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Bolt-Head-Milling Machines, of which the following is a specication.

The object of my invention is to construct a machine for automatically milling heads upon bolts and like objects, as fully described hereinafter.

By my invention a square head can be cut upon a bolt-blank by placing the blank in the chuck of the machine, and two sides of the head will be cut when the blank is moved in contact with a rotating milling-cutter, and by turning the bolt one-half turn the other two sides of the head are brought into position to be cut when the blank is moved a second time into contact withl a rotating millingcutter, as fully described hereinafter.

The machine which I will now proceed to describe is a double machine, in which two bolts can be headed at the same time, and while I have illustrated the machine as arranged to cut a square head it will be understood that the machine can be constructed to cut different-shaped heads upon the bolts, as desired.

In the accompanying drawings, Figure 1 is a side view of my improved bolt-head-milling machine. Fig. 2 is a plan View. F'ig. 3 is a rear view. Fig. 4 is a transverse section on the line 4 e, Fig. 2. Fig. 5 is a section on the line 5 5, Fig. 4. Fig. 6 is a section on the line 6 6, Fig. L1. Fig. 7 is au enlarged sectional view on the line 7 7, Fig. 2. Fig. 7a is a detail view of part of Fig. 7. Fig. 8 is a section on the line 8 8, Fig. 7. Fig. 9 is an enlarged sectional view on the line 9 9, Fig. 1. Fig. 10 is a section on the line 10 10, Fig, 1. Fig. 11 is a section of the chuck on the line 11 11, Fig. 9. Fig. 12 is a sectional View on the line 12 12, Fig. 10. Fig. 13 is a sectional plan view ou the line 13 13, Fig. 4. Fig. 14 is a detailed perspective View of a portion of the machine. Figs. 15 and 16 are diagram views showing the chuck in its two positions, and Fig. 17 is a perspective View of a bolt after having a square head cut thereon.

A is the frame of the machine, supported on suitable legs a a, in the present instance, and mounted in bearings a' on this frame is a shaft B, upon which the milling-wheel B' is mounted. On this shaft is also'a gear- Wheel B2, which meshes with a pinion con an intermediate shaft C, and ou this intermediate shaft is a gear-wheel C', meshing with a pinion c2 on the main driving-shaft C of the machine. On this driving-shaft is a beltpulley.

In the fiange of the milling-wheel B is an annular groove b2, separating the flange into two sections. Each section has a series of transverse slots in its periphery, and mounted in each slot is a cutter b. These cutters are held in place by bolts and nuts b. The shanks of the bolts pass between the cutters, and the head of each bolt overlaps two cutters. The cutting ends of the cutters b pro- 4ject into the annular groove b2, the projection depending upon the size of the bolt to be headed and the character of the head to be cut. If a bolt-blank is fed into this annular groove b2 by the mechanism which I will describe hereinafter, the cutters will cut away the blank to form two sides of the head, and by simply turning the boltblank after the two sides are cut the remaining two can be cut by simply passing the blank a second time into the annular groove b2, when the above operation will be repeated.

A bolt-blank is held by the chuck E, Figs. 9, 10, and 11, carried by a carrier-arm D, pivoted at d to a bracket A, bolted rigidly tothe frame A of the machine. The arm D is moved toward and from the rotarymillingcutter B', and the chuck is turned within the arm when the bolt-blank is free of the cutter. There are two arms and driving mechanism therefor on this particular machine, one being a duplicate of the other, and it will be understood that one carryingarm for the chuck may be used when a single machine is desired Without departing from my invention; but I prefer to construct the machine with two carrying-arms and chucks, as the capacity of the machine can be doubled with very little extra expense.

At each end of the machine is a transverse shaft F, mounted in bearings 01,2 on the frame A, and on this shaft is a sleeve F', having a bevel gear-wheel f at its end, which meshes with a bevel gear-wheel g on a longitudinal shaft G at the rear of the machine. Loose on this wheel is a right-angled gear-wheel g', which meshes with the right -angled gearwheel b3 on the shaft B, and the right-angled gearg' meshes with another gear g2, mounted on the intermediate shaft G', carried by suitable bearings, and on this shaft are three gear-Wheels g2 differing in diameter, and secured to the shaft G are also three gearwheels g4,also differing in diameter and meshing with the wheels g2 on the shaft G'. The gear-wheels g2 are each loose on the shaft G', and any one 0f these gears can be keyed to the shaft by moving the rod g5, on which a key is mounted. This form of clutch is common in this type of machine, and the gearing is simply a method of varying the speed of the shaft G according to the work to be performed. 'The shaft 1l has a bevel gear-wheel g at each end, and these gears mesh each with a bevel gear-wheel fon the sleeve F', described above.

Keyed to the sleeve F', Figs. 4 and 5, is a ratchet-wheelf', with which engages a pawl f2 on a weighted leverf2, secured to the shaft F. An arm f4 of the pawl is acted upon by a springf, so as to retain it in its normal position, as shown in Fig. 5, in engagement with the ratchet-wheelf', and this arm f4 is so proportioned that it will strike a bar h, which is notched at h' when the bar is shifted so that the notch will be out of the path of the pawl. When the bar is shifted so that the notch will be in the path of the pawl, the pawl will pass free of the bar and will not be operated to release the ratchet-wheel; but if the pawl strikes the bar it will be thrown out of engagement with the ratchet-wheel and the shaft F will not rotate with the sleeve F'.

On the shaft F is an eccentric F2, around which passes a strap 1l on the connecting-rod I, which is pivoted to a stud t', secured to the arm D, so that as the shaft F and its eccentric are turned the arm will be vibrated on its pivot CZ, so as to move 4vthe bolt-blank held by the chuck toward and from the milling-cutter. A spring w, mounted in a casing on the frame A and connected to the arm D by a rod w', tends to draw the arm away from the milling-wheel and takes up any lost motion.

Loose on the shaft F is asprocket-wheel J, having on its hub a clutch-face, and arranged .Y to slide on and turn with the shaft F is a clutch-sleeve J', also having clutch-teeth arranged to be thrown into and out of engagement with the teeth on the ratchet-Wheel J. Passing around this ratchet-wheel J is a chaillj, which also passes around a ratchetwheel J2, loose on the shaft K, mounted on a bracket K', secured to the arm D, Fig. 8. The sprocket-wheel J2 is held by frictionplates j'A to the shaft K, as clearly shown in Fig. 8, so that during a certain portion of the time the ratchet-wheel will slip on the vshaft K,`while during other portions the friction will be suicient to cause the shaft to turn with the sprocket-wheel. A take-up wheel fu rests against the chain j, Fig. 7. This wheel is carried by a slide e', back of which is a spring e2 within a casing on the frame A. The shaft K has a bevel gear-wheel 7c, which meshes with the bevel gear-wheel Zo' on the short shaft K2, which is also mounted in the bracket K', and on this shaft is an arm 7a2 of the shape shown in Figs. 9 and 10. This arm carries a pin 7a2, which in the present instance is adjustable on the arm. The arm 7a2 extends over the chuck E and has pin 7a4, which the arm e of the chuck strikes when the chuck is thrown over to start the inachine. On the shaft K2 is a pinion e', which meshes with a segmental rack e2 on the chuck E, Fig. 9. The notched sliding bar h, Fig. 4, is connected to a pin e2 on the chuck E by a rod h2, which in the present instance is bent for clearance, as shown in Fig. 4. It will be seen that the moment the chuck is shifted from one position to another within the head of the arm D the har h will also be shifted so as to either throw the notch Zt' in the path of the pawl or move it out of the path of the pawl, so as to cause the arm of the pawl to strike the bar and throw the shaft F out of gear and stop the machine.

Mounted in bearings on the body of the machine is a vertical shaft L, having a handle Zat its upper end and an arm Z' at the lower end, which is connected by a link Z4 to the clutch-shifting arm L', Fig. 7, pivoted at Z2 to the body of the machine. This clutcharm has lugs which engage the clutch-sleeve J', so that when the shaft L is turned the clutch-sleeve will be either thrown into or out of engagement with the teeth of the sprocket-wheel J.

Secured to the vertical shaft L is an arm Z3, and directly below this arm, but loose on the shaft, is a second arm fm.. This lower arm is held in its normal position byaspring m', i'n the present instance attached to the body of the machine.

4A spring Z5 is secured at one end to the clutch-shifting arm L' and at the other end to a pin on the frame of the machine and is for the purpose of keepingr the clutch normally in gear with the sprocket-wheel J. The free end of the clutch-lever L' extends up through the opening in the frame of the machine in the present instance and in line with the arm m, loosely pivoted on the vertical shaft L, and the end ZG of this arm is shaped, as shown in Fig. 14E, so as to be engaged by the loose arm m when it is wished to hold the clutch out of engagement with the teeth on the ratchet-wheel J. The pin` 7c3 on the arm k2 is also in the path of the arm m when the handled screw e of the chuck is thrown over, as in Figs. 9 and l5, so that when the chuckcarrying arm D is moved toward the milling- ICO cutters the pin k3 will strike the arm m and throw it out of engagement with the end Z6 of the clutch-lever L. The moment this clutch-lever is released the spring l5 will move the clutch-lever and its clutch J into engagement with the sprocket-wheel J. Vhen the chuck E is in the position shown in Fig. 16, then the lever 7a2 is shifted sothat its pin 7c3 is out of line with the arm m and inline with the arm Z3, fast to the shaft L, so that when the pin strikes the arm it will shift the lever and throw the clutch J" out of engagement with the sprocket-wheel J.

Referring now to Figs. 9 and 10, pivoted to the arm D at n is a locking-lever N, which engages with a locking-bolt N', arranged to slide in the head' which carries the chuck E. A spring n', resting against a shoulder or collar on the bolt N, tends to force the bolt toward the chuck. The chuck has a segmental groove e4 in its periphery, and at each end of the groove are notches e5 e, into which the bolt can be projected. On the body of the machine is a iixed wedgep for moving the locking-lever out and throwing its bolt N' out of engagement with the chuck E. It will be noticed in referring to Fig. 9 that the lever N has a reduced portion 122, on which slides a sleeve M, and mounted between the sleeve and the head of the arm D is a spring m2. The spring tends to force the sleeve M down in line with the wedge p, so as to force the lever N out as the arn D moves; but as it is desired to control the movement of this lever I provide a shifter-bar M, which has a forked arm m3, resting in an annular groove in the sleeve M. This shifter-baris notched at m4 and is arranged in the path of a springcatch q on the chuck E. This spring-catch when the clutch is shifted from the position of rest, as shown by dotted lines in Fig. 9, to the starting position (shown in full lines) will raise the shifting-bar, and this bar will lift the sleeve M out of line with the wedge p, so that the chuck will not be released from the bolt N. The moment the shifter-bar h is elevated so that the sleeve M will clear the wedge the spring 'n' on the bolt will force the bolt into the chuck and prevent it rotating at the same time the lever N is moved toward the wedge, so that the sleeve M will rest upon the wedge clear of its working face when released by the catch Q. The wedgep is so shaped that when the arm D is moved to its forward position to bring the blank in the path of the cutters the sleeve M is clear of the wedge and will be forced down by the spring 'm2 into line with the wedge, so that on the return of the arm D the wedge will act upon the sleeve M and draw the bolt N', but the bolt will not be completely clear of the chuck untilthe blank is clear of the cutters. In the meantime the clutch J has been thrown over into contact with the sprocketthe shaft K as the shaft K is locked to the clutch E, which is prevented from turning by the bolt N; but as soon as this bolt N is withdrawn the chuck is then free to rotate, and motion will be imparted to it through the friction-plates, the shaft K K2, and pinion e', which engages the segmental rack on the chuck E. The chuck is then thrown over to the position shown in Fig. 16, and the arm D then moves forward again, so as to feed the blank to the cutters to cut the two remaining sides, in the present instance, of the bolt-blank. When the chuck is turned, the lever 7a2 is also turned to the position shown by dotted lines in Fig. 9 and in full lines in Fig. 16, and the pin k3 on this lever is then out of line with the lever m and in line with the lever Z3, fast to the vertical shaft L, so that when the arm is moved forward the pin willV strike this lever Z3 and will operate the clutch J to throw it out of engagement with the sprocket-wheel J, and the arm m will catch the end of the lever L and retain the lever and its clutch in the position out of engagement with the sprocket-wheel. When the chuck is turned to the position shown in Fig. 16, the notched stop-bar h is shifted as it is connected to the chuck by the rod h2, so that the notch is out of the path of the arm f4 of the pawl f2, carried by the weighted arm f3. l/Vhen the arm of the pawl comesin contact with the bar h, it will throw the pawl out of engagement with the ratchet-wheel f', and thus will stop the shaft F from rotating.

The construction of the grip mechanism for the chuck is as follows: Referring to Figs. 9, 10, and 11, E is the fixed jaw of the chuck, having a V-shaped groove preferably having ribs on the bearing-face. This jaw is held in place by a screw e, Fig. 11. E2 is the movable jaw of the chuck, which is arranged to slide within the chuck and is forced down into position by the handled screw e. This screw works within a nut e5 in the chuck, and springs e6 on bolts e7 tend to keep the jaw in contact with the screw. The screw e travels in a slotin the head of the arm D, so that it can be shifted from one position to another. When it is desired to clamp the bolt-blank :c in the chuck, all that it is necessary is to pass the blank into the chuck from the rear until the blank strikes a stop t, projecting down from the arm D in front of the chuck. Then the handled screw e is given a turn, so as to force the movable jaw toward the fixed jaw of the chuck, clamping the blank a; rigidly to the chuck.

The operation of the machine is as follows: If a square head is to be cut on a bolt, as shown in Fig. 17, for instance, the millingcutters on the milling-wheel B are set the proper distance apart, so that two sides of the bolt will be cut simultaneously. The bolt-blanks of any length desired are placed in the chuck from the rear and adjusted so as to strike' the stops t. screw e of the chuck is turned so as to vclamp Then the handled 1 ICS the bolt-blank to the chuck. `It will be understood that the milling-wheel is driven continuously, and in order to move the chuck forward all that is necessary is to push the handled screw e of the chuck from the position shown by dotted lines in Fig. 9 to the position shown in full lines in said figure. This moves the lever k2, throwing the pin 7c3 of said lever into linewith the lever m. In the meantime the notched bar h by the move ment of the chuck has been withdrawn, so as to release the pawl f2 in order to couple the sleeve F to the shaft F. This will cause the arm D to move toward the milling-wheel, and the cutters of this wheelwill cut the boltblank to form two sides of the head. As the arm D moves forward the pin k3 trips the lever m and releases the clutch-arm, so that the clutch J will be drawn into engagement with the sprocket-wheel J by its spring and so that the sprocket-wheel will turn with the shaft F, causing the sprocket-wheel J2 to turn loose between its friction-plates on its shaft K, owing to the fact that the chuck is held fixed to the arm by the bolt N'. On the return movement, however, of the arm D the bolt N will be withdrawn from engagement with the chuck by the wedge p on the frame pushing thelever N out. Thus the chuck when the bolt-blank is clear of the milling-cutters is free to turn and will be turned by the-pinion e engaging the rack e2 on the chuck E, as there is sufficient friction between the sprocket-wheel J2 and the friction-plates to turn the chuck when not held by the spring-bolt. The chuck will then be turned from the position shown in Fig. 15 to the position shown in Fig. 16, and the handled screw e will be moved over, so as to relieve the lever k2, which will drop into the position lshown in Fig. 16, and the pin 7c3 will be in line then with the lever Z3, which is fast to the shaft L. The turning of the chuck will turn the bolt one-quarter turn, so as to bring the blank in position and so that when it is moved forward in contact with the cut-l ters the other two sides of the head will be cut, forming a square-headed bolt. As the arm D is moved forward on its second stroke the pin k3 comes in contact with the lever Z3, forcing the clutch J out of engagement with the sprocket-Wheel J, thus stopping the rotation of the shafts K K2. In the meantime the notched bar h has been thrown over by the movement of the chuck E, so as to interfere with the movement of the pawl f2 as it rotates, and when the pawl strikes the bar it will be thrown out of engagement with the ratchet-wheel f' and disconnect the shaft F from the driven sleeve F', so that the mechanism, with the exception of the milling-wheel, will stop. Then the operator simply turns the handled screw e to release the cut bolt-blank,

which is removed and another placed in position, the handled screw again tightened, and the chuck thrown over into position, so as to again set the mechanism in motion, when the above operation is repeated.

The machine shown in the drawings, as mentioned above, is a double machine with one handled screw and chuck on each side of the milling-wheel, and one operator can readily place the `bolt-blanks in each chuck without interferingwith the continuous operation of the machine.

The present machine is designed to cut a square-headed bolt; but it will be understood that when a hexagonal head is to be cut on the bolt the mechanism is simply changed to give the carrrier three turns and a like movement to the chuck.

l claim as my invention- 1. The combination in a bolt-head-cutting machine, of a milling-wheel having a series of cutters,I a carrier pivoted to the frame of the machine, a chuck for holding a blank to be cut and Xed to the carrier so as to be movable therewith in a line substantially radial relatively to the milling-wheel,and means for operating the chuck so as to move the blank into the path of the cutters, substantially as described.

2. The combination in a machine for cutting bolt-heads, of a supporting-frame, a rotary milling-wheel thereon having cutters, a chuck, a carrier for said chuck consisting of an arm pivoted to the frame, mechanism including a shaft and a bar constructed to be reciprocated extending between the arm and the shaft, whereby the carrier is moved in a line substantially radial to the wheel toward and from the same, and means for turning the chuck during the time that the blank held thereby is out of contact with the cutters, substantially as described.

3. The combination in a machine for cutting bolt-heads, of a rotary milling-cutter having two sets of teeth spaced apart with their cutting edges facing each other, a chuck, a pivoted arm carrying the chuck, a driven shaft, connection between the .shaft and the arm by which the arm is moved toward and from the milling-wheel, a chuck mounted in said arm, shifting mechanism connected to said chuck so that when the chuck is moved from one position to another in said arm it will throw the driving mechanism into gear and when shifted in the opposite position will throw the driving mechanism out of gear, substantially as described.

4. The combination in a bolt-head-milling machine, of a milling-cutter, a carrying-arm, means for moving the carrying-arm toward and from the cuttera chuck carried by the arm, means for rotating the chuck, a driven shaft, means for throwing the shaft into and out of engagement with the driving mechanism, a sprocket-wheel loose on the shaft and connected with the rotating means of the chuck, a clutch arranged to slide on the shaft and engage the sprocket-wheel, a lever for operating said clutch, a shaft having an arm IIO connected to the said lever and having another arm,a catch-lever forholding the clutchlever out of engagement with the sprocketwheel, a lever on the carrier-arm, and means for shifting the lever so that it will either engage the catch-lever or the lever to operate the clutch, substantially as described.

5. rlhe combination in a bolt-head-cutting machine, of a milling-wheel, a pivoted carrying-arm, a chuck carried by said arm, means for shifting the chuck from one position to another within the arm, a bolt for retaining the lever in either position, and means for operating the bolt, substantially as'described.

6. The combination in a bolt-head-milling machine, of a milling-cutter, a carrier-arm, a chuck carried thereby, means for moving the arm toward and from the cutters, meansfor shifting the chuck within the carrier-arm, a driven shaft, driving mechanism therefor, means for throwing the driving mechanism into and out of gear, mechanism for turning t he chuck within the carrier-arm, and a clutch for throwing said mechanism into and out of gear, the whole being so arranged that the carrier can be moved twice toward and from the cutters and the clutch turned between the first and second movements, substantially as described.

7. The combination in a bolt-head-milling machine, of the milling-cutter, a pivoted carrying-arm, a chuck for the blank carried by said arm, means for shifting the chuck, a driving-shaft, means connecting the driving-shaft with the carrying-arm, a sleeve, means for driving said sleeve, a ratchet-wheel on said sleeve, a weighted arm on the driven shaft, a pawl carried by said arm, a bar connected to the chuck, said. bar being so arranged that when the chuck is shifted it will be moved into the path of the pawl and throw the driven shaft out of engagement with the sleeve, substantially as described.

8. The combination in a bolt-head-milling machine, of a milling-tool, a pivoted carrying-arm, a chuck mounted in said arm', means on the chuck forgripping the bolt-blank, teeth in the periphery of the chuck`a pinion engaging said teeth, a driven shaft for the said pinion, friction mechanism, a locking device for the chuck and a clutch between the driven shaft and the pinion, substantially1V as described.

9. The combination in a bolthead-milling machine, of cutters, a pivoted arm, a chuck mounted in the arm, means for operating the chuck, a driven shaft, an eccentric on the shaft, a connecting-rod connecting the eccentric with the pivoted arm, and a spring coupled to the arm and tending to draw it toward the eccentric, substantially as and for the purpose specified.

l0. The combination in abolt-head-cutting machine, of the cutters, a pivoted4 carryingarm, a chuck mounted in said arm, means for shifting the chuck from one position to another, a lock for locking the chuckin either position, an arm pivoted to the carrier and engaging the lock, a movable sleeve on the arm, a spring tending to force the sleeve down, a wedge on the frame with which the sleeve can engage, a notched bar coupled to the sleeve, a spring-latch carried by the chuck and arranged to engage the notched bar so that when the chuck is thrown over in one position the notched bar will be engaged and will lift the sleeve out of line with the wedge, substantially as described.

1l. The combination of the cutters, a carrier, means for moving the carrier toward and from the'cutters, a chuck mounted in the carrier and arranged to be turned from one position to another, an arm projecting from the chuck, a lever 7a2 pivoted to the carrier having a pin 7c in the path of the arm of the chuck, a pin 7c3 carried by said lever k2, a vertical shaft, two levers on said shaft, one of said levers being loose and the other fast to the shaft, the loose lever being a detentlever, a clutch, a shifting-arm therefor with which the detent-lever engages, an arm on the said vertical shaft connected to the clutch-lever, and a spring, the whole being so constructed that when the chuck is thrown over in one position the pin k3 will be in line with one lever, and when thrown ovei into the other position the pin kB will be in line with the other lever, substantially as described.

l2. The combination in a machine for milling the heads of bolts, of the milling-cutter, a chuck for holding a bolt-blank, said chuck being'open at both ends and having means for gripping said blank, a carrier for the chuck, means for moving said carrier and a stop rigidly fixed to the carrier for limiting the inward movement of the blank, said stop projecting from a point on the carrier outside of the path of motion of the bolt-blank into said path and intersecting the surface containing the line of motion of the milling-cutter when the carrier is in a position such that the blank is operated upon, substantially'as described.

13. The combination in a machine for milling the heads of bolts, of a milling-cutter, a pivoted carrier, means for operating the carrier, a cylindrical chuck mounted in the carrier, a segmental rack on the periphery of the chuck, a pinion with which the rack engages, means for turning the pinion at intervals, a handled screw passing throughV the rotating millingcutters, a Vslottedl pivoted carrier, a cylindrical chuck within the carrier having ixed and movable jaws, and a screw IOC for forcing the movable jaw toward the fixed l shafts having means connecting them to the arms whereby said arms are given a reciproeating motion, means for driving said shafts and for driving the milling-Wheel, a chuck carried by each arm, and means for rotating the chuck, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

BENJAMIN F. PAIS'I.

Witnesses:

WILL. A. BARR, Jos. H. KLEIN.

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