US2995961A - Adjustable manual feed - Google Patents

Description

Aug. 15, 1961 B. s- ELDRIDGE ETAL 2,995,961

ADJUSTABLE MANUAL FEED Filed June 17, 1957 2 Sheets-Sheet 1 ATTORNEYfi Aug. 15, 1961 B. s. ELDRIDGE ETAL 2,995,961

ADJUSTABLEMANUAL FEED Filed June 17, 1957 2 Sheets-Sheet 2 ATTORNEYS United States Patent 2,995,961 ADJUSTABLE MANUAL FEED Benjamin S. Eldridge and Edward C. Wan'ick, Pittsburgh, Pa., assignors to Rockwell Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed June 17, 1957, Ser. No. 666,028 3 Claims. (Cl. 7734.6)

This invention relates to a fully adjustable hand feed device for a drill press or the like and more particularly an angular adjustment mounting for the hand lever on the rotatable quill feed shaft for assuring convenient positioning of the lever for close controlled rotation of the feed shaft during repeated up or down feed travel of the quill in a drill press. More specifically, the invention relates to a mounting construction which allows the operator to adjust the hand feed lever independently of the feed shaft so as to place the handle in its most convenient position for repeating operation of a drill press.

Drill presses are generally constructed with vertically movable cylindrically shaped quills reciprocably mounted Within a drill press head, a drill spindle journaled in the quill and carrying a tool chuck at its lower end and a spline connection at its upper end for driving connection with a suitable vari-speed driven element such as a pulley wheel all as shown, for example, in United States Letters Patent No. 2,360,921 to C. A. Wiken issued October 24, 1944. Feeding movement of the drilling tool is usually elfected through a pinion shaft journalled in the drill press head and having a pinion drive connection to a rack gear formed integrally in the back face of the quill. In the case of many drill presses, a hand feed only is provided through a right angularly disposed hand feed lever fixedly or adjustably slidably carried in the protruding end of the pinion shaft. In those having a power feed, it is customery to provide as an alternative the same kind of a hand feed lever. The hand feed is usually used in any case where sustained quantity production operations necessitating a power feed and more or less automatic control for economical use is undesirable.

Since tool life and proper drilling of work pieces requires a relatively constant feed movement at varying speeds depending upon the nature of the material being drilled and the rotational speed of the drill bit, it is highly desirable to dispose the hand feed lever at an angle which enables the operator to best apply the required feeding force during the actual drilling operation without suffering muscle tension and fatigue. It has been determined in practice that some operators, to avoid muscle strain and fatigue, prefer the hand lever disposed in the for- Ward facing quadrant of the circular path of movement of the feed lever during actual drilling, that other operators prefer the hand lever in either the upward or downward facing quadrant of the circular lever path during actual drilling and that still others prefer the feed lever in still other portions of the circular path of movement during actual drilling.

Attempts have been made to solve this problem either by providing the pinion shaft with a multiplicity of radiating lever arms or with circumferential spline-like notches for receiving a locking finger movable into and out of the circumferential notches and carried by a hand feed lever rotatably journalled in the pinion shaft as disclosed in United States Letters Patent 1,011,183 of December 12, 1911 issued to Gifiord. Neither of these solutions has achieved any appreciable acceptance as the prominence in the commercial field of the cross bar type of hand feed lever of the aforementioned Wiken Patent 2,360,921 attests. The principal disadvantages of both appear to be the relatively small number of available angular positions obtainable and the production and assembly expense involved in providing either of the structures.

It, accordingly, is the primary object of this invention to provide an economically manufactured hand feed lever assembly for manual rotation of a tool feed shaft which is fully and quickly adjustable to a desired length and infinite angles of leverage.

Another object of this invention is to provide a fully adjustable hand feed control lever for manually controlling the rotation of a tool feed shaft with locking means to securely fix the hand feed lever in any selected adjusted position until a new adjusted position is desired by an operator of the device.

Still another object of this invention is to provide a fully adjustable hand feed lever for a drill press requiring a minimum of special parts and additional assembly operations to assure a production cost low enough to provide the advantages of such an adjustable hand feed lever without any increase in cost of the tool itself.

Other objects of the invention will become apparent as the description proceeds in connection with the appended claims and accompanying drawing, wherein:

FIGURE 1 is a front elevational view of the adjustable feed lever assembly of this invention mounted on a drill press;

FIGURE 2 is a side elevation of the feed lever assembly of FIGURE 1 on an enlarged scale with parts broken away for clarity of illustration;

FIGURE 3 is longitudinal sectional view on a still larger scale of the feed lever assembly mounting; and

FIGURE 4 is an exploded perspective view of the feed lever assembly of this invention shown in relation to its drill press pinion feed shaft.

Referring now to FIGURE 1 of the drawing, there is illustrated a drill press head 9 having an end portion of a pinion feed shaft 10 for controlling the feed movement or travel of the conventional quill and spindle (not shown) and the associated chuck 11 and its tool (not shown). While a drill press is illustrated, it will be appreciated that any other tool or device having a shaft which must be manually rotated may be provided with the hand lever assembly herein disclosed.

The center of the end face of shaft 10 is drilled and tapped to provide a mounting bore 12 (FIGURE 3) having a pair of annularly enlarged recesses 14 and 16 at its outer end as shown in detail in the drawing. Surrounding the recess 16 is an annular series of radially directed serrations 18 forming a gripping face adapted to matingly engage a corresponding serrated gripping face 19 (FIGURE 4) provided on a lever support member or collar 20 adapted to be mounted on the end of pinion shaft 10 as hereinafter pointed out.

The collar 20 has a through bore 22 which is journalled on the plain shank portion 23 of a combined support and clamp stud 24 threaded into the tapped bore 12. The stud 24 has a knurled knob 26 provided with a clamp face 27 fixed on the end thereof. An annular series of radially directed serrations 28 formed concentrically about recesses 29 and 30 in the end of collar 20 forms the gripping face 19 for mating engagement with the serrations 18 on the end of shaft 10. The respective recesses 16 and.

30 are provided so the serrations 18 and 28 can completely intermesh and form a full engagement positive coupling between shaft 10 and collar 20 when the stud 24 is threaded home into bore 12 to engage clamp face 27 of knurled knob 26 with the face of reduced diameter boss 31 of collar 20 and force collar 20 and gripping face 19 toward and into mated locked engagement with the serrated end face of pinion shaft 10.

The depth of the recesses 16 and 30 are exaggerated for clarity as shown in FIGURE 3, it being understood of course that the depth of the recesses need be only slightly greater than the depth of the serrations 18 or 28 to assure complete engagement. While serrations 18 and 28 may be of any suitable dimensions and number, it is preferable to provide serrations sufliciently small in size and great in number to' assure an infinite angular adjustability of collar 20 with respect to shaft 10. In practice, a preferred structure found adequate utilizes serrations of a height of approximately of an inch and numbering 48 on each mating face and recesses 16 and 30 are of an inch deep.

Slidably mounted in a through bore 32, which extends in the form of a chord through the annular support collar 20, is a hand feed lever 34 having spherical hand grip knobs 36 threaded on reduced opposite ends 37 thereof. The axis of bore 32 is substantially at right angles to the axis of bore 22 and is offset therefrom so the respective bores do not intersect. A threaded radial bore 38 extends from the peripheral face of collar 20 and intersects at right angles bore 32. A knurled headed thumb set screw 40 threads into bore 38 and, when tightened, clamps the hand lever 34 in any desired axial position to enable the operator to secure the desired protrusion of the lever end to be grasped so that a minimum applied force can be used to secure the feed rate best suited to the workpiece and rotational speed of the Spindle. This adjustment together with the infinite angular adjustment of collar 20 provided by this invention assures the full adjustability needed to permit an operator to position the hand feed lever at the individually preferred position at the time of actual drilling and at the same time secure the leverage advantage which most nearly enables attainment of the desired feed rate with the same minimum applied force at all times. Thus strain and fatigue is held to a minimum.

A cut-out portion indicated at 41 in the peripheral surface of collar 20 is preferably provided in the periphery of collar 20 at the end of bore 32 which faces the lever end grasped in use. The bottom wall of cut-out portion 41 is provided with a blind bore 42, which intersects bore '32. Blind bore 42 receives a coiled spring 44 and a steel ball 46 which is biased firmly against an assembled hand lever 34. The frictional drag exerted by the ball 46 prevents the lever 34 from freely sliding in bore 32 so that the hand lever will be held frictionally in its selected adjusted position while set screw 40 is tightened or if the operator omits to tighten the set screw. Accidental sliding of hand lever 34 in bore 32 is thus largely automatically prevented.

In operation, an operator in obtaining a desired angular position of hand lever 34 loosens stud 24 by rotating the knurled knob 26 a suflicient amount to allow the serrations 28 of collar 20 to be moved axially out of engagement with the serrations 18 on the end face of pinion shaft 10. The collar 20 is then freed for rotation to enable the operator to place the hand lever 34 in the desired position to assure proper angular positioning of the hand lever during the drilling travel of the quill. This positioning can be properly gauged by the operator by pressing the collar 20 toward the serrated end of shaft by hand to engage the serrations and rotating the hand lever assembly and pinion shaft to bring the drill into contact with the work. After the angular position is thus determined, knob 26 is rotated to tightly clamp collar between clamp face 27 and the opposed end of shaft 10 with serrations 18 and 28 interlocked to provide a positive coupling between the collar 20 and the pinion shaft 10.

With the angular adjustment fixed, set screw 40 is then loosened to adjust the working length of lever 34 to secure the desired leverage. The drill press is then started and the drilling operations can be carried out with minimum strain and fatigue until a change in the workpiece necessitates a change in adjustment of either or both the angular position or leverage of the hand feed lever.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A hand feed for manually feeding a tool relative to a workpiece comprising a tool supporting slide assembly; a feed shaft drivingly connected to said assembly and having an annular series of shallow serrations on an end face and a threaded axial bore opening through said shaft end face centrally of said annular series of serrations; a lever support collar having a mating annular series of serrations on an end face adapted to lockingly engage said shaft end face serrations; a bore extending axially through said collar centrally of said mating serrations; a stud threaded at one end and having a knob fixedly mounted at its opposite end passing through the bore of said collar and threaded into said shaft bore to journal said collar on said shaft and selectively clamp said collar to said shaft end upon threading said stud home in said shaft bore thereby interlocking the serrations on said collar with the serrations on said shaft end face and coupling said collar to said shaft for unitary rotation; a lever bore extending through said collar substantially at right angles to, but offset to one side of, said axially extending collar bore; and a lever disposed in said lever bore with an end protruding transversely from said collar and adapted to be grasped for rotating said feed shaft and effecting sliding movement of said tool supporting slide assembly and tool toward said workpiece.

2. The hand feed of claim 1 wherein said collar is provided with a threaded bore intersecting said lever bore; a set screw is threaded into said bore for move- References Cited in the file of this patent UNITED STATES PATENTS 385,063 Lodge et al. June 26, 1888 1,011,183 Gifford Dec. 12, 1911 2,360,921 Wiken Oct. 24, 1944 FOREIGN PATENTS 58,159 Sweden May 24, 1922

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