US1215804A

US1215804A - Thread-milling machine.

Info

Publication number: US1215804A
Application number: US3130715A
Authority: US
Inventors: Arthur Peart Holden; Philip Morgan
Original assignee: Individual
Current assignee: Individual
Priority date: 1915-05-29
Filing date: 1915-05-29
Publication date: 1917-02-13
Anticipated expiration: 1934-02-13

Description

N. A G En 0 M .P. & N rr. D L 0 H P. am

THREAD MILLING MACHINE. APPLICATION FILED MAY 2s. I9I5.

Patented Fab. 13, 1917.

3 SHEETS-SHEET I www@ l I sgi A. P. HOLDEN @L P.l MRGAN. THREAD MILLING MACHINE. APPLICATION FILED MAY 29, 1915.

gl QSGL Patentd Feb. 13, 1917.

f Z f@ I' Zd C' A P HOLDEN&P MOR N. THREAD MILLING MACHINE. APPLICATION FILED MAY29 9|5 31,215,89@ Patented Feb. 13, 1917.

3 SHEETS-SHEET 3 f ras n ernten.

ARTHUR PEART HOLDEN .AND PHILIP MORGAN, OF TORONTO, ONTARIO, CANAD.

THREAD-MILLING lMACHINE.

Specification of Letters Patent.

` Patented Feb. I3, i917.

Application led May 29, 1915. Serial No. 31,307.

To all whom t may concern.'

Be it known that we, ARTHUR PEART HOLDEN and PHILIr' MORGAN, both of the city of Toronto, in the county of York and Province of Ontario, Dominion of Canada, have invented certain new and useful Improvements in Thread-Milling Machines;

' and we hereby declare that the following is a full, clear, and exact description of the same. y

In the manufacture of high explosive shells, it isnecessary to bore a blind hole centrally in the base of the shell and thread it for the reinforcing plug which receives the force of the firing charge, no variation being permitted in the'diameter of the hole,

' or the perfection of the thread.

The present machine has been particularly designed for automatically and correctly centering the partly-finished shell to the axis of the revolution of the chuck -which operates to 'simultaneously feed the work in an axial direction during its revolution and determine the pitch of the thread while the milling operation is being performed, the revolution of the chuck on the completion of the thread being automatically arrested, and for perfectly milling -a completed thread to the bottom of a blind hole of this character, so that the threaded stem of the reinforcing plug will completely` in section, showing the feed ring; and Y Fig. YI, is a longitudinal lsection of a high explosive shell showing the reinforcing plug fitted tothe base.

Like characters of reference refer to like parts throughout the specification and drawings.

In the manufacture of shell projectiles,

each shell a, which is drilled and turned to the required size and shape, is provided in the ma:-

Fig. V, is a perspective detail view, partly j the .base a witha. blind hole a, having a perfect thread a3 from the inner to the outer end of the hole. This threaded hole must be of uniform diameter throughout its length to form a tight it`with the threaded shank b of the reinforcing plug b', so that the gas' from the firing charge cannot penetrate between the wall of the hole and the shank.

Rapidity and accuracy are two important factors in the manufacture of this class of article, particularly during war periods, in order to maintain the supply of high-grade ammunition for the requirements at the front.

In order to successfully carry on the manufacture of this type of shell, the milling machine is provided with a substantiallycylindrical work holder or chuck c having an axial bore c therethrough of substantially corresponding shape and dimensions to the external shape and dimensions of the shell a, so that when the partly-finished shell a is inserted into the bore of the cylindrical chuck, it will be automatically and accurately centered.

As shown in Fig. I, the base of the shell a is opposed to the milling tool d, and that part c of the bore c engaging the base a of the shell serves as a positive stop to correctly locate or position the shell within the.

work holder and converges to form a clamping member for engaging that end of the work. i

The opposite end 03 of the axial bore c to the converging end c is threaded to receive a hollow clamping member e, the inner end of the bore evof the clamping member e being of a correspondingshape to the. nose L4-'of the shell a, and the outer surface ofw the clamping member e being threaded to-engage with the threads of the end c3 so that when the clamping member e is tightly screwed into the bore of the cylindrical chuck c, it will bind against the nose Bf the shell a and force the basenof the shell against the converging part .0 "and lock the shell within the chuck, which then will unitedly revolve with the chuck.-

The chuck c is journaled in three bearings f, ff, f supported by the frame g, and

bearings f,.f is threaded as shown at h, of corresponding pitch to the thread a3' to be milled`in the blind. hole af in the base of the shell a.

"the outer surface of the chuck between the Encircling the chuck c between the bearings f, f', is a divided feed ring z' having itsl bore threaded to correspond with and engage the thread h on the outer surface of the chuck c, the bearings f, f preventing the lateral movement of the feed ring. As shown in Fig. VV, the feed ring z' consists of two members z",., pivoted at one side to the flanges f4 of the bearings f, f', so that they can be swung into open or closed relation with the cylindrical chuck o for the `purpose of disengaging the threaded surface 3 of the bore of the feed ring from the threaded surface Z1. of the cylindrical chuck, when it is desired to quickly move the chuck in the direction of the milling tool d.

Pivoted to the free end of the member z" is a bolt which, in its operative position, enters between the forks j ofthe member 2'. The bolt j, as shown in Fig. V, is provided with a nut lo to engage the forks j for the purpose of drawing the free ends of the members z", d together and bringing by a bolt m passing through an elongated the threadedsurface 3 of the bore of the feed ring into engagement with the threads It of the cylindrical chuck. Splined on the cylindrical chuck c, between the bearings f, f, is a Worm wheel Z partly covered by a guard casing g, and cut in the bore of the worm wheel and the perimeter of the chuck c, are keyways for the keys a which, while causing the united revolution of the worm wheel and chuck, permit the chuck to slide axially through the worm wheel, the lateral movement of the worm wheel being prevented by the bearings f, f, which are located close to its side faces. The worm wheel Z meshes with a worm Z mounted on a shaft Z3, provided with a pulley Z, and journaled near one end in a rocking bearing m, and at the other end in a movable bearing m slidablyr connected to the frame g slot m8 in the bearing.

Bolted to the frame g is an arm 0, to which is fulcrumed a lever o havingN a shoulder o engaging a li-p p on the movable bearing m to support the bearing when holding the Worm Z in mesh with the worm wheel Z, and on the end of the chuck c is a collar p having a liange p engaging the lever o.

The starting position of the partslis that shown in Figs. I and II, the chuck c in this position being moved lengthwise to its limit of movement in the direction indicated by arrow, its further movement in that direction being arrested by the flange p on the collar p abutting against the bearing f.

The flanged collar p, p is provided with a stop pin q and the bearing 7 1s provided with a stop pin g, the chuck when coming to the starting position being turned in the direction indicated by arrow 1n Fig.

lip, the movable bearing ve of the ore of the chuck, the shell then being correctly centered and tightly vclamped within the cylindrical chuck.

The milling tool ZZ, fixed on a Shaft al mounted in bearings cZ movable length- Wise and laterally of the frame g, is then shifted to commence milling at the inner end of the blind hole a, motion being transmitted through the pulley Z3 tothe shaft d and milling tool al.

When the milling tool aZ has been corhtly against the converging part rectly positioned, the worm Z is moved into mesh with the Worm wheel Z and the leve o is moved into position to support the movable bearing m for the worm and main'- tain the worm in mesh with the worm wheel while the milling operation is being performed.

When the Worm is brought into mesh with the worm wheel, the revolution of the chuck and shell starts, and the milling tool commences to mill the thread in theblind hole a.

During the revolution ofthe chuck, the meshing of the threaded surface l1. of the chuck with the threaded surface 3 of the feed ring e' feeds the chuck in a direction away from the milling tool and` not only causes the milling of the thread in the blind hole a corresponding inthe pitch to that of the threaded surfaces l1., 3, but also causes the pin gto clear the pin Q.

During this feed of the chuck c, the ange p gradually works the lever 0 outward, as

and ultimately disengages the shoulder o form the lip p. v

When the shoulder is disengaged from the lm. drops into the position indicated in dotted lines in Figs. I and II, releasing the worm from mesh with the worm wheel and stopping the motion of the chuck, this stop motion being timed to correspond with the completion of the milling of the thread in the blind hole. The clamping member e is then'removed and the threaded shell is withdrawn from the chuck, a freshA shell is inserted in the chuck, and the clamping member is replaced. To quickly move the chuck-to lits limit of motion in the direction of the millin tool al, the nut lc is slackened on the bo t y', the

.. members z", z' of the feed ring are opened to disengage the threaded surface 3 from the inner end of the blind hole and the worm is moved into mesh with the worm wheel to repeat'the milling operation.

By means of this construction, a perfectlyformed thread can be rapidly milled in the blind hole, and without supervision, it being only necessary for the operator to place the work in and remove it from the machine.

Having thus fully described the nature of our invention, what we claim as new and desire to secure by Letters Patent, is:-- y

l. A'thread milling machine comprising a set of bearings, an axially-movable cylindrical work holder journaled therein having its outer surface threaded, threaded means engaging with the threaded surface of the work holder for causing its axial movement, a worm wheel mounted on the work holder, means for slidably securing the work holder to the worm wheel, a worm meshing with the worm wheel, journaled at one end in a rockable bearing and at the other in a movable bearing, and a pivoted support for the movable bearing displaced therefrom by the chuck when it has reached the limitV of movement in an axial direction.

2. A thread milling machine comprising a set of bearings, a cylindrical work holder journaled therein having its outer surface threaded, a clamp having its inner surface threaded to engage with the threaded surface ofthe work holder, said clamp consisting of two clamping members located be? tween two of the bearings, and aclamping bolt and nut closing them together, a' worm wheel mounted `on `the work holder,'a key entered in a keyway in the worm wheel and work holder for slidably securing the work holder to the worm wheel, a worm meshing with the worm wheel, journaled at one end in a rockable bearing and at the other in a movable bearing, and a pivoted support for the ymovable bearing displaced therefrom by the chuck when it has reached its limit of movement inan axial direction.

an axially-movable hollow rotatable, work holder havin ward one en clamping means within the bore to hold the work therein, a gear wheel to which the work holder is splined so that it is rotated by the worm wheel, but is free to move axially through it, the outer surface of the work holder having a feed thread thereon, and means engaging with the feed thread to cause the axial movement ofthe work holder during itsrotation.

an axial bore tapering `to\v 4. A thread milling machine comprising a hollow rotatable work holder having an axial boretapering toward one end, a clamping nut adjustable in the other end of said bore, cooperating with the tapering end to correctly position and securely `hold the work within said holder, a bearing in which the work. is journaledand through which it is axiallyrmovable, a gear wheel splined to the work holder so that as it is rotated the work holder will move axially through it, a feed thread on the external surface of the work holder, and means engaging with the feed thread to cause the axial movement of the work holder as it rotates.

5. A- thread milling machine comprising an axially-movable hollow rotatable work holder having an axial bore, clamping means to hold the work there-ima worm wheel splined to the work holder so that the work holder is rotated by it and is free to moveaxially through it, a worm meshing with the worm wheel, a movable bearing for the worm, and a pivoted support for the movable bearing, displaced therefrom by the work holder when it has reached the limit of movement in an axial direction.

6. A thread milling machine comprising a bearing, an axially-movable cylindrical work holder journaled therein having a feed thread on its outer surface, threaded means engagin with the feed thread of the work holder or causing its axial "movement, a worm wheel mounted on fthe work holder, means for slidably securing the work-holder to the worm wheel, a .form meshing with the worin-wheel journaled at one endin a movable bearing, and a pivoted supportfor the movable bearing displaced therefrom by the Work holder when it has reached the limit of movement in an axial direction.

. 7. A thread milling machine comprising Ia bearing, a cylindrical work holder journaled in andaxially movable through. the bearing, a worm wheel splined to the work holder so that the work holder is'free to move axially through it, a worm meshing With the worm wheel to Cause the rotation of the work holder, means for effecting the movement lofthe work holder in an axial direction, and means for dlsengaging 'the worm from the worm wheel when the work J holder has reached its limit of axial move- 3. A thread milling machine comprising 4move axially through it, a worm meshing with the worm wheel, a movable bearing in which one end of the worm is journaled, and

a pivoted support for the movable bearing,

displaced therefrom by the work holder loo;

v when it has reached its limit of movement in an axial direction.

9. In a thread milling machine, the combination of a bearing, an axially-movable Work holder rotatable therein, a Worm Wheel 'splined to the Work holder so that the Work holder is axially movable through it, a Worm meshing with the Worm Wheel, means causing the axial feed movement of the Work holder, and vmeans holding the Worm in mesh With the Worm Wheel displaced by th'e Work holder When it has reached the limit of its axial movement releasing the Worm from the Worm Wheel.

10. In a thread milling machine, the combination of a bearing, an axially-movable Work holder rotatable therein, a Worm Wheel splined on the Work holder so that the Work holder is axially movable through it, means for holding the Worm Wheel' against axial movement, a Worm meshing With the Worm Wheel, means causing the axial feed movel ment of the Work holder, and means holding the Worm in mesh With the Worm Wheel displaced by the Work holder When it has reached the limit of its axial movement releasing the vvorm from the Worm Wheel.

11. In a thread milling machine, an axially-movable cylindrical Work holder, means causing the axial feed movement of the Work holder, a Worm Wheel splined on the Work holder so'that the Work holder is axially movable through it, a Worm meshing With the Worm Wheel, a movable bearing in which the Worm is journaled, and a support for the movable bearing holding the Worm in mesh With the Worm Wheel displaced by the Work holder When it has reached the limit of its axial movement re- .bination of a bearing, an axially-movabley cyllndrical Work holder rotatable therein, a.

leasing the Worm from the Worm Wheel.

12. In a thread milling machine, the4 com- Worm Wheel splined on the Work holder so that the Work holder is axially movable through it, means preventing the movement of the Worm Wheel in an axial direction, a Worm meshing With the Worm Wheel, a movable bearing in Which the Worm is journaled, and means holding the movable bearing to maintain the Wormin mesh With the Worm Wheel displaced by the Work holder when it has reached the limit of its axial movement releasing the Worm from the Worm Wheel.

13. In a thread milling machine, the combination of a bearing, an axially-movable` Work holder rotatable therein, .means for causing the axial feed movement of the Work holder, a Worm Wheel splined'on the Work holder so that the Work holder is axially movable through it, means preventing the movement -of the Worm Wheel in an axial direction, a Worm meshing with the worm Wheel, a movable bearing in Which the Worm is journaled, and a .pivoted arm, supporting the movable bearing holding the Worm in mesh with the Worm Wheel displaced by `With the Worm Wheel displaced'by the Work holder when it has reached the limit of its axial movement releasing vthe Worm from mesh with the Worm Wheel.

Toronto, May 10th, 1915. Y

, ARTHUR PEART HOLDEN.

PHILIP MORGAN. i