US2529680A - Slotting machine - Google Patents

Description

Nov, 14, 31959 T. F. ESERKALN ETAL 9 SLOTTING MACHINE Filed July 11, 1946 4 Sheets-Sheet 1 INVENTORS yerkzln Qr/Qy c2? Pmmske W M w NOW 9 1950 T. F. ESERKALN ETAL. 5 9

SLOTTING MACHINE Filed July 11, 1946 4 Sheets-Sheet 2 Novo 14,. 1950 Filed July 11, 1946 T. F. ESERKALN ETTAL SLOTTING MACHINE 4 Sheets-Sheet 4 Patented Nov. 14, 1950 SLOTTING MACHINE Theodore F. Eserkaln, Wauwatosa, and Charles A. Parske, Milwaukee, Wis., assignors to Kearney & Trecker Corporation, West Allis, Wis., a corporation of Wisconsin Application July 11, 1946, Serial N0. 682,850

9 Claims. (CI. 9040) This invention relates generally to machine tools and more particularly to an improved slotting mechanism for a machine tool.

A general object of the invention is to provide an improved machine tool of the reciprocating ram type.

Another object of the invention is to provide an improved slotting attachment which may be mounted on any of various machine tools.

Another object of the invention is to provide an improved control mechanism for changing the range of movement of a ram in a slotting mechanism, which is adjustable while the ram is reciproeating.

Another object is to provide an improved slotting mechanism having novel selective means to vary the range of ram movement.

According to this invention, an improved machine tool slotting mechanism has been provided wherein the tool carrying ram may be adjusted for operation through a predetermined distance, the adjustment being made while the ram is reciprocating. The ram is power driven from a motor mounted on the machine frame and connected to drive a step pulley transmission which provides means for varying the rate of ram reciprocation. A crankcase adjustably mounted in the frame carries an oscillatory ram actuating arm so arranged that movement of the crankcase provides means for adjusting the range of ram reciprocation within prescribed limits. Appropriate indicia are provided to indicate the range setting of the ram, while a drive mechanism within the crankcase transmits power to drive the ram regardless of the position of the case in the frame.

The foregoing and other objects of this invention, which will become more fully apparent from the following detailed description of an embodiment thereof, may be achieved by the apparatus herein described by way of example in connection with the illustration of its structural components in the accompanying drawing, in which:

7 Figure 1 is a front elevational view of a slotting attachment, incorporating the invention herein disclosed, mounted on a machine tool for operation on a workpiece;

Fig. 2 is a vertical sectional View ofthe slotting attachment shown in- Fig. 1-, showing the drive mechanism adjusted to provide maximum ram travel;

Fig. 3 is a view generally similar to Fig. 2, showing the drive mechanism adjusted to provide a shorter ram travel;

Fig. 4 is a detailed vertical sectional view of drive mechanism contained within the adjustably positioned crankcase, showing the power drive train;

Fig. 5 is a view in vertical transverse section on the plane of the line 55 in Fig. 1 of the slotting attachment'mounted on a machine tool showing the ram and crankcase mounting in greater detail; and,

Fig. 6 is a fragmentary horizontal sectional view, taken on the plane of lines 66 in Figs. 2 and 5, showing the drive train from the driven pulley to the ram within the attachment frame.

The particular structure illustrated in the.

drawing as constituting mechanism disclosing the invention, is a slotting attachment adapted for mounting on a machine tool, although it is to be understood that the novel features thereof may be incorporated in other machine tools of the reciprocating ram type with equal advantage.

Referring more specifically to the drawings, the slotting attachment embodying the invention comprises a frame 9, mounted for angular positioning on an upright column 10 of a horizontal spindle, knee type milling machine. A ram ll, reciprocally mounted in the attachment frame 9 serves to support a cutting tool l2 on its lower end in a manner to effect a slotting operation upon a workpiece l3, clamped on a work supporting table I4 adjustably carried by the column [0 of the machine tool, as shown in Fig. 1. Power for driving the ram 1 I is derived from a motor l5 adjustably carried on the top of the attachment frame 9. The rate of ram movement and, consequently, of tool reciprocation, is controlled by adjusting a step pulley transmission 19 in well known manner. According to this invention, the range of reciprocation of the ram l I may be precisely controlled by adjusting the position of a crankcase or gear case 20 movably mounted within the frame 9. Selective positioning of the crankcase 20 serves to vary the ram stroke, by changing the efiective operating length of an oscillating actuating arm 2| mounted upon the crankcase and slidably engaging a swivel block 22 journalled in the side of the ram.

The shape of a slot 23 cut in the workpiece I3 is determined in part by the contour of the cutting edge of the tool I 2, while the depth of the slot may be set by selectively positioning the various machine tool elements, including the table I, in a manner well known to those skilled in machine tool operation. In addition, when a particular slot has been completed, the workpiece may be repositioned relative to the cutter to permit succeeding slots to be cut. When a slotting operation is being performed on an arcuate element either on the periphery of or within an opening in a workpiece, the workpiece may be mounted upon a rotary table (not shown) in a manner to permit accurate angular positioning thereof.

The motor 5 is hingedly mounted for adjustment on the attachment frame 9 by means of a pin 26, as shown in Fig. 5. A step pulley 21, constituting the driving unit of th pulley transmission l9, as shown in Fig. 2, is keyed directly to the armature shaft extending from the motor l5. A complementary driven step pulley 28 of the transmission [9 is rotatably journalled in the attachment frame 8. Both pulleys are housed within an inclosed compartment 29 in the frame, in such a manner that the respective pulley grooves are parallelly mated to receive a V-belt 30. For servicing and adjusting the pulley transmission mechanism, access to the compartment may be had through an opening closed by a re movable bolted cover 3 i. The tension of the belt 39 1s readily varied by manipulating a knob 32 pinned to the upper end of an adjusting screw 33. As shown, the screw 33 is threaded in a lug 34 integrally formed with and extending from the motor frame, with the lower end of the screw abutting against the attachment frame and supporting the motor l5. When the knob and screw are rotated, the motor i5 is raised or lowered to tension or release the belt on the pulleys. By selectively positioning the belt 30 in the various combinations of grooves as shown in Figs. 2 and 6, a splined shaft 35, that is slidably received by internal splines in the pulley 28 may be driven at any one of five speeds. Access to the pulley transmission IQ, for changing the position of the belt in the various grooves of the pulleys 2i and 28, is obtained through an opening 35 provided in the frame 8, as shown in Fig. 6.

The range of ram reciprocation is selectively changed by positioning the crankcase 20 within the attachment frame 9, in a manner to change the effective length of the oscillating actuating arm 2| in acting upon the swivel block 22. As shown in Figs. 2 and 5, the crankcase 20 is provided with a dovetailed portion 3? which is slidably received for transverse movement in a correspondingly shaped groove 33 machined in a horizontally disposed guide block 39 attached to the inside of cover plate 40 constituting the front of the frame 9. The crankcase assembly 25, actuating arm 2!, swivel block 22 and ram H are assembled as a unit on the cover plate 40, before the cover is bolted to the frame.

The crankcase assembly 20 is adjustably positioned by selectively rotating a handwheel 43, shown in Figs. 1, 2, and 3, mounted on the extending end of a screw shaft 4:1 journalled in the frame 9 in a plane parallel to the plane of crankcase movement. A bore in the crankcase is threaded to receive the threads of the screw shaft 44, in a manner to efiect movement of the crankcase 2!] whenever the handwheel 43 is rotated. Appropriate indicia 46, marked on the crankcase structure, when read against a zero mark 41, through a window in the cover plate 4|], as shown in Fig. 1, permits the operator to readily ascertain the setting of the crankcase and, consequently, the range setting of the tool-retaining ram Thus, the machine operator can readily adjust the length of ram stroke to meet the requirements of a particular slotting operation.

When the handwheel is rotated to adjust the position of the crankcase assembly 20, the oscillating actuating arm 2| is slidably positioned within the swivel block 22 to provide for transmitting a desired effective movement to the ram When so adjusted to a desired operating range, the ram and the tool l2, carried thereby, will be reciprocated precisely within the prescribed range. With this structure, the operator can readily adjust the length of ram stroke while the ram is performing a slotting operation upon a workpiece.

In order to provide a power drive to effect reciprocation of the ram I for any desired adj ustment of the crankcase assembly 20, a linkage mechanism is contained therein, as shown in detail in Figs. 4 and 6. The splined driving shaft 35 is supported in the crankcase 20 on a double ball bearing 5|. A pinion 52, integrally formed on the inner end of the splined shaft 35, meshes with a ring gear 53 carried on a crankshaft 54, that is journalled in the respective side walls of the crankcase 2|] in bearings 55 and 56. Thus, the crankshaft 54 may be rotatably driven through interaction of the ring gear and pinion 52 and 53 at a speed rate determined by the setting of the belt 30 in the step pulley transmission H].

A connecting rod 51, journalled on the throw of the crankshaft 54, is operatively connected with the extending end of a forked arm 58 by means of a wrist pin 59, as shown in Fig. 4. The arm 58 is keyed to a rock shaft 60, journalled in and extending from the crankcase 20 with its axis parallel to that of the crankshaft 54. When the crankshaft 54 is rotatably driven, the connecting rod 5'! will cause the arm 58 to oscillate through a prescribed distance for each rotation of the crankshaft 54 and, consequently, the shaft 60 will be partially rotated or oscillated through the same angular displacement. An offset carrier arm 6| is keyed to the forwardly extending end of the rockshaft BB and serves to support the actuating Thus, when the shaft 6|! is oscillated by the connecting rod 51, the carrier arm 6| will be correspondingly oscillated or reciprocated along a fixed arcuate path.

As shown in Figs. 2, 5, and 6, the actuating arm 2| presents a cylindrical surface that slidably engages the interior of a bore 62 in the swivel block 22. Since the swivel block 22 is rotatably journalled on a bearing 63 mounted in the side of the ram I, as shown in Figs. 5 and 6, the block is free to swivel about its axis as well as slide upon the arm 2| and any oscillatory movement of the arm will be translated into endwise movement of the ram I I that is slidably retained within a ram track 64 in the cover plate 40. Selective adjustment of the crankcase assembly, as aforedescribed, serves to change the effective length or setting of the actuating arm in the swivel block 22. Thus, as viewed in Figs. 2 and 6, when the crankcase assembly 20 is positioned in the extreme left hand position within the frame 9, the actuating arm 2| will operate at its maximum effective length and serves to effect the maximum travel of the ram within the ram track 54.

Any adjustment of the crankcase assembly 20 rightwardly as seen in the drawings, will serve to reposition the actuating arm 2| in the swivel block 22 and, consequently, will reduce its effective length and the range of ram travel. For example, as shown in Fig. 3, with the crankcase assembly 20 adjusted to effect a reduction in the range of ram travel, the arm 2| will have been moved rightwardly in the swivel block 22 a set distance. With this setting, the distance between the center of the rockshaft 60 and the pivot center of the swivel block 22 is reduced so that the oscillatory action of the arm 2| will effect a proportionately shorter ram travel. When the two centers coincide, the arm 2|.will be positioned for zero ram travel. A dotted line showing in Fig. 3 indicates the lowest position which the ram and tool reaches for the particular range setting shown, the actual distance of travel being indicated by an arrow 65 as compared with the maximum distance of travel indicated by an arrow 66 in Fig. 2. This distance of ram travel will be indicated to the machine operator by the previously described range indicia 46 and each ram stroke will be of identical length, the arrangement providing infinitely variable range adjustment within the fixed limits of crankcase adjustment. I

In order that a slotting operation may be performed on a workpiece having an inclined surface, a swivel mounting is provided for the attachment. The frame 9 is provided with a rearwardly extending flange 10, as shown in Figs. 5 and 6, having a circular engaging surface H, which is disposed to concentrically engage a similar surface on a backing plate 12. The plate is in this instance supported on a pair of extending overarms l3, slidably mounted in the machine tool column ID. The plate is rigidly clamped to the column by means of a gib 14, in a manner well known to the machine tool art. The attachment frame Sis rigidly secured to the plate 12 by means of four T-bolts and nuts 15, evenly spaced about the periphery of the flange 10. The T-bolts ride in a circular T-slot [6 machined in the supporting plate 12. When the slotting attachment is to be set to cut slots at a desired'angle, the machine operator-need only loosen the four nuts andswivel the entire unit to the desired position and reclamp the nuts to rigidly hold the slotting attachment in a selected angular position. Indicia 11 marked on the peripheral edge of the flange 10, when read against a zero mark 78 on the plate 12, as shown in Fig. 5, enables the o erator to readily ascertain the exact angular setting of the attachment.

From the foregoing detailed description of the illustrative structures set forth herein to exemplify the present invention, it will be apparent that there has been provided an improved machine tool of the reciprocating ram type that is especially adapted for cutting slots in workpieces under various conditions of operation.

Although the exemplary embodiment of the invention has been described in considerable detail in order to fully disclose a practical working apparatus incorporating the invention, it is to be understood that the particular structure shown and described is illustrative only and that the various characteristics of the invention may be incorporated in other structural forms without departing from the spirit and scope of the invention as defined in the subjoined claims.

The principles of the invention having now been fully explained in connection with the foregoing description of embodying structure, we hereby claim as our invention:

1. In a machine tool of the reciprocatory ram type, a frame, a ram slidably mounted in said frame for reciprocating movement along its 1ongitudinal axis, power driven actuating mechanism slidably mounted in said frame for adjusting movement along a path transverse to the longitudinal axis of said ram, an oscillatory arm carried by and driven by said actuating mechanism for oscillatory movement in the direction of 6-: movement of said ram, and linkageslidably engaging said arm and operatively interconnecting said arm and said ram, the arrangement being such that movement of said actuating mechanism relative to said ram axis causes said arm to slide in said linkage andchanges the effective length of said oscillatory arm thereby affording adjustment of the length of the stroke of movement imparted to said ram.

2. In a machine tool of the reciprocatory ram type, a frame, a ram slidably mounted in said frame for longitudinal reciprocating movement,

power driven actuating mechanism slidablyl mounted in said frame for adjusting movement transversely of the axis of reciprocatory move-.

ment of said ram, an oscillatory actuating member operatively connected to and carried by said slidably mounted actuating mechanism and slidably connected with said ram to transmit movement to said ram in manner to reciprocate it, means to adjust the position of said actuating mechanism transversely of said ram to change the slidable connection between said oscillatory actuating member and said ram for regulating the action of said oscillatory actuating member, upon said ram to vary the length of its stroke, and indicating means responsive to movement of said actuating mechanism in said frame and operative to indicate the ram stroke.

3. In a machine tool of the reciprocatoryram type, a frame, a ram slidably mounted in said frame for reciprocating movement along its longitudinal axis, a power driven actuating shaft rotatably mounted in said frame, oscillatory mechanism slidably mounted in said framefor adjusting movement in direction transverse to the longitudinal axis of said ram and slidably connected to said power driven shaft for actuation thereby in any position, and motion transmitting linkage including an oscillatory arm operatively connected to be oscillated by said actuating mechanism and slidably connected to said ram, the arrangement being such that the effective length of said arm may be varied by adjusting the position of said actuating mechanism relative to said ram axis for sliding said arm in its connection with said ram to thereby vary the length of the stroke of said ram.

4. In a slotting mechanism, a frame, a motor adjustably mounted on said frame, adjusting means to effect selective adjustment of said motor, a driven shaft journalled in said frame, a

'flxed-step pulley transmission interconnecting said motor and said driven shaft to provide a plurality of speed rates therefor, a crankcase adjustably mounted in said frame, a crankshaft journalled in said crankcase, interconnecting driving mechanism to transmit power from said driven shaft to said crankshaft regardless of the position of said crankcase, a connecting rod disposed for operation on said crankshaft, an arm assembly journalled in said crankcase and reciprocally driven by said connecting rod, a tool i retaining ram slidably mounted in said frame,

mechanism and extending from said case, an actuating arm fixedly carried by said shaft, a ram slidably mounted in said frame, a swivel-jointed connector mounted on said ram and carrying said arm, and a selectively operable adjusting mechanism disposed to position said transmission case in said frame, whereby the effective movement of said arm in said connector may be varied to change the length of ram stroke while said ram is reciprocating.

6. In a machine tool slotting mechanism, a frame, a carrier mechanism adjustably mounted in said frame, a power source, a transmission driven by said power source, a coupling journalled in said frame to connect said transmission and said carrier mechanism, an adjusting mechanism operative to selectively adjust the position of said carrier mechanism in said frame, a tool retaining ram slidably mounted for reciprocation in said frame, a swivel block journalled in said ram, and an actuating arm connected to and extending from said carrier mechanism with said arm slidably engaging said swivel block, whereby the manipulation of said carrier adjusting mechanism serves to change the effective position of said arm in said block and effect a corresponding change in the range of ram movement.

7. A slotting mechanism for a machine tool comprising a frame mountable on a machine tool, a tool retaining ram reciprocably carried by said frame, a swivel block journalled in said ram, a power source, a crankcase adjustably carried in said frame, a crankshaft journalled in said crankcase and rotatively driven by said power source, a secondary shaft mounted in said frame,

a connecting linkage between said crankshaft and said secondary shaft to effect rotative reciprocation of said secondary shaft, and an arm fixedly mounted on said secondary shaft and slidably mounted in said ram swivel block, whereby the range of ram reciprocation may be varied by selectively positioning said crankcase to vary the effective setting of said arm in said ram block.

8. A slotting attachment for a machine tool comprising a frame, a reciprocal ram slidably mounted in said frame, a power source mounted on said frame, a crankcase mounted for slidable adjustment in said frame, a crankshaft rotatably journalled in said crankcase, a variable speed transmission driven from said power source and connected to drive said crankshaft in any adjusted position of said crankcase, a bellcrank operably journalled in said crankcase, a connecting rod operably attached to said crankshaft and to said bellcrank, a swivel block journalled in said ram, and a pivot arm fixedly carried by said bellcrank and slidably disposed in said block, whereby said ram is reciprocally driven from said power source to perform a slotting operation.

9. In a slotting attachment for a milling machine having a work holding table, a frame disposed to be attached to a milling machine in cooperating relationship with its work holding table, said frame constituting a housing for driving mechanism and presenting an opening at one side, a cover plate disposed to close said opening, said plate being removably secured to said frame, a slotting tool carrying ram slidably mounted on said cover plate in manner to extend therefrom toward the work holding table, a ram driving transmission mechanism slidably mounted on said cover plate for movement transversely of the sliding movement of said ram, a pendulum arm carried by said transmission mechanism and arranged to be oscillated thereby, and linkage slidably connected with said pendulum arm and operatively connecting it with said ram for reciprocating said ram, the arrangement being such that movement of said transmission mechanism along said cover plate relative to said ram changes the effective length of said pendulum arm in manner to adjust the length of the stroke of said ram, said transmission mechanism and said ram being removable from said frame with said cover plate as a unit.

THEODORE F. ESERKALN. CHARLES A. PARSKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 116,394 Banks June 27, 1871 596,528 Morton Jan. 4, 1898 678,172 Grist July 9, 1901 678,341 Holmberg July 9, 1901 699,551 McKinney May 6, 1902 790,259 Mills May 16, 1905 791,732 Taylor June 6, 1905

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