US1487690A - Method of and apparatus for drilling - Google Patents

Description

M rch 1s 1924. 1,487,690

c. MARTl METHOD OF AND APPARATUS FOR DRILLING Filed Sept. 24, 1920' Patented Mar. 18, 1924.

iaaaeaa omrso STATES PATENT OFFICE.

CHARLES MARTI, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO THE MARTIAN' MANU- FACTURING ('10., INCL, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

METHOD OF AND APPARATUS FOR- DRILLING.

Application filed September 24, 1920. Serial No. 412,574.

To all whom it may concern.

Be it known that I, CHARLES MARTI, a citizen of the Republicof Switzerland, residing in East Orange, county of Essex, and

State of New Jersey, have invented an Improvement in Methods of and Apparatus for Drilling, of which the following is a specification. v

The present invention relates to an im- 1 provement in method of and apparatus for drilling, one object being to prevent the breakage of drills particularly in so far as such breakage occurs substantially coincident with the passage of the drill throguh the farther or emergence surface of the article in which the drill is operated.

Mechanics have appreciated that the greater proportion of drill breakage, particularly of small drills, occurs at this point in the operation of drilling and they have adopted expedients for preventing it, such for example as reducing the rate of feed just as the drill is about to penetrate the farther surface of the object being drilled. It is true that this precaution on the part of an operator will save drills to'some extent but at the same time, it requires practice to be effective and also slows down the work of drilling to a considerable extent. It is therefore proposed to eliminate the skill and judgment of the operator by providing a method and suitable apparatus in connection with the use of which no judgment as to rate of speed need be exercised except so far as is necessary in the ordinary operation of drilling without re ard to the passage of the drill through the farther surface of the article being drilled.

The application of my invention is illustrated in the drawings accompanying the present specification and in which Figure 1 is a fragmentary view of a drill press in elevation parts of the improved apparatus being broken away and parts be-- ing shown in section,

Figure 2, a view in transverse vertical section on the line 2-2 of Figure 1,

Figure 3, a view in elevation of a modified form of apparatus for practicing my improved method, i 7

Figure 4, a top plan view of the same, Figure 5, a view partly in vertical section showing one embodiment of the invention applied as an integral part of a drill press, and

Figure 6, a'view in elevation of the cap illustrated in Figure 5.

Referring to the drawings, a drill 1 of the ordinary type is operatively secured to a chuck 2 which in turn is rotated by a spindle 3, said spindle being also capable of longitudinal movement toward "and away from the drill "press table 4, said movement being commonly efiected by means of a rack 5 cooperating with a pinion 6 mounted on a shaft 7, said shaft being rotated by means of a lever 8 or other suitable hand operated member.

Referring more particularly to Figure 3 which illustrates a simple device for aiding the operation of my improved method, the drill 1 is shown as extending between the prongs 9 of a powerful spring 10 having a bearing surface 11 for the chuck or other drill carrying member. In the practice of my improved method, it is contemplated that the drill will be advanced normally through the article to be drilled until it reaches a predetermined position therein, this position being approximately where the drill point will pierce the remote'or far surface of the article. At this point, I interpose the yielding resistance to the further advance of the drill, said resistance being maintained until the cutting. edge of the drill has passed entirely through the remote surface. This resistance may be produced by any suitable means but I have found that a steel spring is of great effectiveness for the desired purpose. Where a resistance member such as a spring 10 is used, the operator will slide the prongs 9 into position astride of the drill at any time before the critical position is reached, the critical position in this .connection meaning that point in the advance of the drill at which the foremost cutting edge is about to pierce the remote surface of the article. This type of spring may conveniently be used Where the articles tobe drilled. are of uniform thickness and where each drilling operation is practically a repetition of the former operation on the same machine.

Where it is contemplatedthat the method is to be used in connection with a more varied character of Work, suitable apparatus may be embodied in the drilling machine either as an attachment thereto or as an integral part thereof. It is obvious that the principle of interposing the yielding resistance may be applied in a great variety of ways and by means of varying forms of mechanism. Referring now more particularly to Figures 1 and 2 which illustrate'an attachment to a standard form of drill press, it will be noted that this attachment comprises a spring compressing member 12, having a threaded portion 13 adapted to be secured to the shaft 7 of the drill press. This threaded portion 13 is preferably a lefthanded thread so that the spring compressing member may rotate. in'the direction of the rotation of the shaft 7 when the same is actuated by the operator and without becoming disengaged from said shaft during said operation. A spring 14 may be secured so as to rotate with spring compressing member 12 by means of a pin 15 passing through one leg of said spring and securing the same to said member 12. The spring compressing member is also provided with a projecting lug or pin 16 adapted to engage one free end 17 of the spring 14 and press the same toward the other end 18 of said spring, the position of said end 18'being fixed by means of a projecting lug 19 secured to a cap or housing 20 which may be made in two portions secured together by rivets or other suitable means. This housing 20 is loosely mounted on a stud 21 which may conveniently be formed integral with the spring compressing member 12, said housing being retained against movement of rotation by means of a lever having one end 22 engaging peripheral projections 28 of the housing, while the other end 24 engages a rigid portion 25 of the drill press head. The stud 21 which projects from each side of the member 12 is proportioned to support loosely the lever which slides longitudinally with respect to said stud in order to engage and disengage the projections 23 of the housing 20. This means for setting the stationary position of the housing 20 and therefore of the spring retaining or resisting pin 19 is provided to give a wider range of adjustability so that the same device may be eifective in. connection with the drilling of articles of varying shapes and thicknesses.

In operating the attachment, the drill is first moved into a position.corresponding substantially with that indicated in Figure l, in other words, so that the point of the drill will be resting upon the upper level of the drill press table or bed. The parts of the apparatus. will then be adjusted so that pin 19, secured to the housingwill occupy a fixed position byreason' of theengagement,

of the lever against a rigid portion'of! the framework of. thf machinearid the. .pin 16 w l e in easeme t erased 17 of the spring 14, the other free end of said spring being pressed against the now stationary pin 19. By reyersing the direction of the feeding handle, the drill will then be raised to permit the piece of work to be positioned on the drill press. The normal operation'of drilling and feeding then takes place and'the operator need have no further concern respecting the distance to feed the drill or with respect to the emergence of the drill through the article on the remote side. He simply continues feeding normally until the feeding operation is completely pre. vented by reason of the compression of spring 14 bringing the free end 1'? into contact with the now stationary free end 18, thus permitting no further rotation of the shaft 7 through which the longitudinal advance of the drill is accomplished.

Referring now to i igure 5, it will be clear that the present invention may be embodied directly in a drill press structure, thus per mitting the elimination of the lever. In the device shown in Figure 5, a spring compressing member 26 may be associated in any suitable secure relation with the drill feeding pinion of the drill press. said member 26 being provided with a stud 27 upon which is loosely mounted a cap 28 having a plurality of holes 29 adjacent to its periphery, said holes being arranged to receive a pin or pins 30 mounted in the head of the drill press. The cap 28 is also provided with aspring detaining pin 31 which becomes a stationary stop when the holes 29 engage the pins 30. The cap is retained in operative position as described by means of a compression spring 32 interposed between said cap and a head 33 secured to the outer end of the stud 27. Thus, when it is desired to change the position of the pin 31, the cap 28 is raised against resistance of the spring 32 and rotated to the desired position. Similarly, if it is desired to throw the drill protecting mechanism out of operation, the cap may be raised out of engagement with the pins 30 thus withdrawing the stop pin 31 from the path of movement of the spring 14 and the cap may then be positioned with portions of its undersurface resting against the tops of the pins 30.

Whatever form of apparatus is used, it will be clear that the interposing of a suitable yielding resistance to the advance of the drill just before the drill is about to penetrate the far side of the object drilled will prevent the sudden forward thrust of the drill through thethin metal. Thus, it may be said that the yielding resistance interposed' as described, is me. sense substituted for thenorm'al resistanceof the metal to theadvance of the drill during, the last increment of its passage through the article. Where the yieldingresistance is'in the form of a t i lie are l us ted a scribed or equivalent thereto, the drilling operation will be stopped automatically at the proper time so that, after a proper setting of the instrument has been effected, the operator need give no attention to stopping the feeding of the drill.

I claim as my invention:

1. In a drill press the combination of a longitudinally movable drill'holder, a pinion operatively connected therewith, a housing to support said pinion, a lug secured eccentrically to said pinion and rotatable therewith, a stop operatively secured to the housing, and means interposed between the lug and the stop to yieldingly oppose rotation of the pinion.

2. In a drill press the combination of a longitudinally movable drill holder, a pinion operatively connected therewith, a housing to support said pinion, a lug secured eccentrically to said pinion and rotatable therewith, a stop operatively secured to the housing, means for adjusting the position of the stop, and means interposed between the lug and the stop to yieldingly oppose rotation of the pinion.

3. Apparatus for drilling comprising in combination a longitudinally movable drill holder, a pinion operatively connected therewith, a housing to support said pinion and means interposed between said housing and said pinion to yieldingly oppose drill advancing rotation of the pinion.

4. Apparatus for drilling comprising in combination a longitudinally movable drill holder, a pinion operatively connected therewith, a housing to support said pinion and means interposed between said housing and said pinion to yieldingly oppose drill advancing rotation of the pinion after a predetermined increment of unopposed rotation thereof.

5. Apparatus for drilling comprising in combination a longitudinally movable drill holder, a pinion operatively connected therewith, a housing to support said pinion, means interposed between sald housing and saidpinion to yieldingly oppose drill advancing rotation of the pinion, and means for positively stopping said drill advancing rotation of the pinion.

6. Apparatus for drilling comprising in combination a longitudinally movable drill holder, a pinion operatively connected therewith, a housing to support said pinion, means interposed between said housing and said pinion to yieldingly oppose drill advancing rotation of the pinion, and means for positively stopping said drill advancing rotation of the pinion after a predetermined increment of yieldingly opposed rotation thereof.

7. In a drill press the combination of a longitudinally movable'drill holder, a pinion operatively connected therewith, a housing to support said pinion, a lug secured eccentrically to said pinion and rotatable therewith, a stop operatively secured to the housing, and a U-shaped spring having one leg positioned to engage" the stop and the other positioned to engage the lug to yieldingly oppose movement of rotation of the pinion. 8. In a drill press-the combination of a drill press head, a longitudinally movable drill holder, a pinion operatively connected therewith and supported by said head, a disc rotatable with the pinion and having a lug, a housing having a stop member extending toward the disc, a spring positioned to engage both the lug and the stop member, and

means to retain the housing against movement of rotation when the pinion is rotated in spring compressing direction.

9. An attachment for drill presses comprising a lever, a housing mounted on said lever, a spring positioned in the housing, means secured to the housing to engage a portion of said spring to .limit movementthereof, and means movable within the housing to engage another portion of said spring to move the same'toward the first mentioned portion. c

10. An attachment for drill presses comprising in combination a U-shaped spring member, a stop positioned to engage one end of said member to limit movement thereof, means for moving the other end of the spring member toward the first mentioned end, and means for retaining the stop in fixed position with respect to a drill press to which the attachment is secured.

11. An attachment for drill presses comprising a lever, a housing mounted on said lever, a spring in the housing, a stop fixed with respect to the housing and positioned to engage one portion of the spring, and

spring engaging means movable within the housing to press another portion of the I spring toward the first mentioned portion. In testimony whereof, I have signed my name to this specification this 17th day of September, 1920.

CHARLES MARTI.

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