CA1197123A - Portable slotting and grooving attachment - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

The attachment is to be fitted to a lathe or 2 milling machine. It is designed for slotting (keyway cutting) and grooving operations. It comprises an elongated boxshape housing having a longitudinally extending shaft journaled therein. The rear end of the shaft is operatively connected to an electric motor, while the front end carries a first bevel gear which meshes with a second bevel gear fixed to a hollow spindle and, perpendicular thereto journaled in the front end of the housing. A rotary cutting tool is removably fixed within the spindle and projects laterally of the housing. The attachment can be detachably secured to the carriage of a lathe or to the head portion of a milling machine.

Description

7 ~L 3 ~ \

FI~LD OF THE INVENTION
The present invention relates generally to lathes and milling machines, more specifically to an improved attachement removably mounted on such machines.
BACKGROUND OF THE INVENTION
Lathes and milling machines are used for cuttin~
external keyways and screw or drill threads, facing Rnd boring operations, ~traight and taper milling etc., on a workpiece held in the machine.
However the only known machine able to cut internal keyways, whether straight or of progressive depth is a type of reciprocating chisel which cùts bit by bit while moving along the workpiece. Moreover thi3 machine i~ very expe~sive and must be properly centered relative to the workpiece.
OBJECl`S OF THE INVENTION
Accordingly a prime object of the present inventlon is to provide a machina which can easily and precisely cut an internal as well as an external keyway in a workpiece as well a3 ~piral or circular grooves~ e~ternal or internal.
Another important object of the invention ls to provide a machine of the above type which i9 portable and which can be removably secured to a conventional lathe or milling machine.
It is yet another object of the invention to provide a machine of the above type which has itq own power source, can be handledas one unit and which operate~ in a fast manner.

~ 2 --SUMMARY OF THE INVENTION
The above and other objects and adventages of the present lnvention are reali~ed according to a preferred embodiment comprising an elongated and generally box-shape housing provided with mounting means for removable attachment to the carriage of a conventional lathe or to the head portion of a conventional milling machine.
A longitudinally extending drive shait i~ ~ournaled within the housing.
One end of the drive shaft i9 operAtively connected to the output shaft of a power source, such as, for example, an electric motor, said power source being carried by one end portion of said housing.
Thé opposite end of the drive shaft drives a tool carrier consisting oi a hollow spindle extending normal to the shait and housing and adapted to receive and drive a rotary cutting tool projecting laterally from the ~econd end portion o the housing. Fixing means are provided to removably and rigidly secure the tool within the drlve spindle.
If a lathe is being used, the work is secured to the headstock and extends longitudinally rearwardly tllerefrom such that its end i8 proximate the carriAge. The work m&y thus be rotated or not. If the work i~ stationary the invention can be used to cut an internal slot or keyway.
If the work is made to turn, a spiral or circular internal (as well as external) groove can be cut. Similarly the attachment o the invention can be mounted on the he~d portion of a milling machine ~ as i8 sometime~ needed for larger work.

7~L23 BRIEF DESCRIPTION OF THE DRAWINGS
The above will be more clearly understood b~ having referral to the preferred embodiment, illustrated by way of the accompanying drawings in which:
Ficùre 1 is a side eleva-tion of the attachment ac-cording to the invention;
Figure 2 is a top plan view, without the housing cover, of the att~chment;
Fi.gure 3 is a forward end elevation of i:hç att.ach-ment also showing work in dashed outline;
Figure 4 is a perspective view of -the attachment cu',~ ing an internal slot in a workpiece;
Figure 5 is a side elevation of the rear end por-tion of the attachment, partly sectioned;
Figure 6 is a longitudinal secti.on of the forwarct end of the attachment and a portion of a workpiece being C~lt;
Figure 7 is a side elevation of a lathe partly in dotted lines showing the attachment mounted on the carriage thereof, and Fi.sr~re 8 is a perspective view of a milling machine par-tly in dotted lines with the attachment mounted thereon.
Like numcrals refer to like elements throughout the drawings; ` ' .-.
~ . . . .
DETAILED DESCRI.PTION OE THE PREFERRED E~ODlME~
Referring to figures 1, 2, 7 and 8 the:re is shown the attachment 1 consisting of an elonga-ted box-shape housing

2 including a solid bar like portion 2' with spaced parallel flanges 2''. i~n independent power source such as an elec-tric motor 3 is fixed to -the housing 2 at the rear end there-of. The rear end portion 2''' of bar 2' is of reducecl thi~.k-ness, as shown in figures 1 and 2, and by a sui-table bracket 7~3 conventional tool holder is adapted to be removably .ecured, for example, to the carriage 4 of a lathe 5 (fiyure 7) or the head portion 6' ofa milling machine 6 (figurt-i 3), after removal of the part carrying the vertical spindle of said machine. The motor 3 is fixed to a plate 7 by brackets 9, 10 and bolts 11, and plate 7 has an L-shape extension ,3 fixed to the rear end of bar 2'.
Housing 2 preferably has a removable top, cross-sectionally U-shape, cover 12 secured by screws 13 to flanges 2l' as seen clearly in figures 1 and 4.
Ho~sing 2 carries a rotatable drive shaft 14 which is journaled at both its front and rear end poxtions in ball bearing assemblies 15 and 16 respectively.
The rear end of shaft 14 is rigidly secured ir, a connector element 17 by a set screw 18 as is the ourE~ shaft 19 of motor 3 by another set screw 20 thereby causing shaft 14 to rotate bodily with output shaft 19.
The front end of drive shaft 14 is provided with a first gear me~ns constituted by a bevel gear 21 rigidly fixed to the shaft by a set screw 22.
Referring now to figure 6 there is shown the worling elements o~ attachment 1. These elements include a second gear means constituted by a second bevel gear 23 rigidly secured to a drive spindle 24 by a set screw -25. Gear 23 meshes with gear 21. r Drive spindle 24 is journaled wi-thin the fron-t end of housing 2 by means of tapered roller bearin~s 26 and ball bearings 28. ~lle -ssembly is retained in position by a ~ollar 27 screwed onto the outer end of spindle 24.
SpindLe 24 has an axial bore whlch is threaded in its portion surrounded by gear 23, as shown at 2'~. A standard ~197~2 rotary cutti~y tool 30 is removably inserted in the bore of spindle 24. ~he threaded end 30' of the shank of to~l 30 is screwed in the threads 29 of spindle 24 and lo~ked by a lock screw 31. The cutting en~ portion 32 of tool 3C pro-Ject~;
laterally of housinc~ 2.
A second lock means is provided to positive5y prev-ent tool 30 from loosening relative to the drive spindle 24 during operation. This lock means comprises a set screw 33 laterally engaging the shank of tool 30 and accessible through an end bore 34 made in bar 2'. A cap 30 removably closes an opening made in cover 12 to gain access ~o lock screw 31.
Figures 3, 4, and 6 to 8 show one of the operations that can be carried out by attachment 1 when mounted horizon-tally on the carriage 4 of a lathe S or vertically on head portion 6' of a m:illing machine 6. A workpiece, onsisting of a pipe 40, is fixed to the headstock of the lathe or to .'~, table 6'' of mllling machine 6. Cutting tool 30 is in the process of cutting an internal slot or keyway 41 in pipe 40, the headstock OL ta~le 6'' being s-tationary.
It will be readily grasped that, i~ ~}le la,:l~e carriage or the tab]e 6" is moved -transversely o:f the work-piece cutting, a keyway of progressive clepth or shall.owness can be easily executed. On the other hand,if pipe-4Q is~made to rotate, a spiral groove or a circu]ar groPve can~just as easily be cut by~ for instance, rotating the headstock and making the carriage 4 of lathe 5 move towards the headstock or remain stationary respectivel.y~

Claims (2)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. An attachment for a lathe or milling machine comprising: an elongated solid bar, with longitudinally-extending spaced parallel flanges, and a rear end portion of reduced thickness adapted to be detachably secured by the tool holder of the carriage of said lathe or of the head portion of said milling machine; a driving motor secured to the rear end of said bar and having an output shaft; a longi-tudinally-extending drive shaft rotatably carried by said bar and having a rear end operatively connected to the said out put shaft, and extending between said flanges; a first bevel gear rigidly secured to the forward end of said drive shaft;
a second bevel gear operatively meshing with said first bevel gear, a drive spindle secured to said second bevel gear and journaled in the forward end of said bar, said spindle being normal to said drive shaft and having an axial bore opening laterally out of said bar, said spindle bore having an internal threading constituting means to secure within said bore the engageable threaded shank of a rotary cutting tool with the cutting portion of said tool projecting laterally of said bar; and a lock screw, also threadedly en-gaged in said internal threading, and rigidly abutting the end of said tool shank.

2. The attachment of claim 1, further including a cover for said shaft and fixed to said flanges, to form a box-shaped housing with said bar; and a cap removably closing a hole in said cover in registry with said lockscrew.