US 2720125 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Oct. 11, 1955 D. R. PALIK DRILL SUPPORTING AND OPERATING DEVICE Filed July 21, 1952 INVENTOR: DONALD A. PAL/KI.
BY WiW Agem.
United States Patent DRILL SUPPORTING AND OPERATING DEVICE Donald R. Palik, Hawthorne, Calif., assignor of two-fifths to Roy Melvin Kerr, South Gate, Calif.
Application July 21, 1952, Serial No. 300,090 1 Claim. (Cl. 77-7 This invention relates generally to the tool art and is concerned more particularly with a holder or extensible fixture for supporting a portable electric drill. Specifisteel components.
.It is a well-recognized fact that such drilling by means of the conventional, portable, drills of the industrial types, supported wholly by the workman, involves a laborious and time-consuming operation. This is due largely to the fact that the workman is required to support the entire weight of the relatively heavy drill while guiding the same into position to properly locate the holes. At the, same time, the operator mustexert considerable force in the axial direction of the drill to cause the latter to penetrate the material being drilled.
While such an operation may be conveniently executed when the drill is directed downwardly, it frequently occurs that the holes must be drilled in horizontal and upward directions so that the operation becomes a difficult one to perform. For example, it frequently occurs that holes must be drilled upwardly in the steel or wooden beams of a ceiling and in such case it is the common practice for the workman to mount a ladder or scaffold to a level adjacent the beams. Upon assuming such a position, the operator holds the portable drill in his hands and directs the rotary drill bit upwardly, simultaneously applying upward pressure to feed the drill into the beam.
Since the upward force is exerted in a laterally offset vertical plane, it follows that the workman is over-balanced in his working position. Consequently, only a portion of the possible upward force can be exerted by the operator and this obviously results in loss of time in drilling the holes. Moreover, such an over-balanced cona portable drill in various positions, the fixture having particular utility in supporting such a drill in vertical positionwith the drill directed upwardly, thereby avoiding the necessity for manually supporting the drill during a drilling operation.
Another object of the invention is to provide a support oryfixture, of the character referred to, which comprises 2,720,125 Patented Oct. 11, 1955 ice generally two telescopic tubes, one of which is adapted to seat against a fixed surface, such as a wall or a floor, the other tube serving as a holder for the portable drill. By this provision, the first or base tube may be fixed against a floor and the holder tube slid axially to move the drill toward and away from the beam or other structural part to be drilled.
Another object of the invention is to provide a drill supporting and operating fixture, of the class indicated, which includes operating means by which the holder tube may be conveniently advanced or extended to feed the drill toward the work and thereafter released to retract the holder tube and drill from the work. In accordance with the present concept, this objective is attained by providing a feeding element which is slidably mounted on the holder tube and which carries a pawl-plate or dog adapted to engage the holder tube when moved in a direction away from the base tube so as to advance or extend the holder tube and the portable drill mounted at its end, and to release the holder tube when the feeding element is slid in the opposite direction. By this means, the holder tube may be advanced with a step-by-step motion to locate the drill bit against the work and to feed the drill bit into the work without requiring physical effort on the part of the workman.
Another object of the invention is to provide a drill support device of the type indicated in which the operating means consists of a pair of toggle-type levers operatively connected between the fixed base tube and the slide element, movement of said levers in a direction to straighten the toggle serving to move the slide element toward the work to be drilled, and breaking of the toggle acting to return the slide element to retracted position. A related object is to provide an operating means in the form of a toggle-type jack which includes a jack handle for actuating the toggle levers, one of said toggle levers being formed integrally with the handle.
A further object is to provide a drill supporting device, of the character referred to, which includes a holder member mounted on the outer end of the extensible holder tube, said member being in the nature of a frame in which the portable drill is held with the motor end of the drill projecting from the open end of the frame. A related object is to provide a plurality of clamping segments at said open end of the frame, these segments being connected at their ends and contractible around the drill housing to retain the drill in place in the holder member. By this clamping means, the holder member may accommodate portable drills of various sizes.
A further object of the invention is to provide a drill supporting fixture in which the base and holder tubes may be made in various lengths so as to adapt the device for particular ranges of movement as the circumstances require in order to locate the drill adjacent the surface to be drilled and to dispose the operating means where it can be conveniently actuated by the workman.
A still further object is to provide a device of this general class which is relatively simple in construction, economical to produce, proof against derangement or getting out of order, and one which is highly efiicient in performing its intended function.
Further objects will appear from the following description and from the drawing, which is intended for the purpose of illustration only, and in which:
Fig. 1 is a perspective view of my drill supporting device, showing the relation of the parts following extension of the holder tube through a predetermined increment of movement;
Fig. 2 is a similar view, illustrating the manner in which the pawl-plate or dog grips the holder tube dur- 3 ing actuation of the operating means through an operative stroke;
Fig. 3 is a cross-sectional View, taken on line 33 of Fig. 2;
Fig. 4 is a fragmentary sectional view of the operating means, illustrating the manner of releasing the feeding pawl;
Fig. 5 is a cross-sectional view, taken on line 5-5 of Fig. 1; and
Fig. 6 is a View similar to Fig. 4, showing an alternative pawl arrangement.
Referring to the drawing in detail, my drill supporting device includes essentially a lower base tube 10 which has a flange-like foot or base 11 at its lower end, the tube 10 preferably being a length of pipe having a lower threaded end screwed into the flange. Welded or otherwise secured to the upper end of the tube Ill is a collar 12 having spaced ears 13.
A second tube 15, hereinafter referred to as the holder tube, is arranged for axial movement within the base tube 10 with a close sliding fit, the upper end of the tube 15 being screw-threaded as shown.
Adapted to be screwed onto the upper threaded end of the holder tube 15 is the lower boss end 17 of a holder member 18. As illustrated, the holder member is in the form of a bifurcated frame having laterally-spaced side walls 19. The upper ends of the walls 19 carry segmental clamping elements 20 and 21. A third clamping element 22 (Fig. 5) is also employed, the several elements being connected to form a complete circle by means of clamping screws 23 screwed through holes in ears 24 formed at the adjoining ends of the segments.
The holder member or frame 18 is adapted to carry a portable drill 25 of any conventional type, having a housing 26 enclosing an electric motor (not shown), the housing having a laterally projecting handle 27. The motor shaft carries a collet 28 for connecting the drill bit 29 to the motor shaft for rotation therewith. The drill 25 also may have a pistol-grip handle 30 at its end opposite the working end of the drill.
To mount the drill 25 on the holder member 18, the segment 22 is first removed and the drill is thereafter slid laterally into the frame. The segment 22 is then reassembled and all of the binder screws 23 are tightened to cause the segments to contract around the drill housing 26 so as to mount the drill firmly in place with the drill bit 29 substantially coaxial with the tubes 10 and 15.
Means are provided for extending the tube 15 relative to the tube 10 so as to advance the drill and its rotary bit toward the work. For example, the drill may be employed for drilling holes in a beam 33 of a ceiling, as illustrated in Fig. l, in which case the supporting device is set up with its base plate 11 resting upon the floor 34, and the drill 25 is moved upwardly to cause the rotary bit 29 to drill a hole in the beam. The operating means for raising the drill 25 includes a slide member having tubular end portions 41 and 42 and a rectangular intermediate portion 43, the latter portion having a transverse opening 44 provided with an upstanding lip 45 at one end.
Disposed within the opening 44 is a pawl-plate or dog 48 having an aperture 49 through which the holder tube 1.5 extends, the aperture being of slightly larger diameter than that of the tube 15. As shown in Fig. 2, one end of the pawl-plate 48 normally rests upon the lip 45 and thus assumes a slightly inclined position so as to cause opposite edges of the aperture 49 to engage or dog against opposite sides of the tube 15. Thus, upward movement of the slide member 40 effects like movement of the tube 15, due to the dogging action of the pawlplate 48. The tubular portion 42 has laterally projecting ears 50.
The operating means for raising the slide member 40, tube 15, holder member 18 and drill 25 includes a handle lever 55 which is pivotally connected to a pin 56 extending between the cars 50, the handle having transversely projecting ears 57 between which extends a pin 58, the ears 57 providing a toggle lever. A second toggle lever 60 has its lower end pivotally connected to a pin 61 extending between the ears 13, the upper end of the lever being pivotally connected to the pin 58.
The drill supporting device having been described in detail, its mode of operation is as next explained. Assuming that it is desired to drill a hole in the beam 33 of a ceiling, the complete device is set up on the floor directly beneath the point where the hole is to be drilled. The workman then assumes a position adjacent the ceiling by mounting a ladder or other support and then grasps the handle 27 in one hand and the handle-lever in his other hand. The workman then forces the operating handle-lever 55 downwardly and during this pivotal movement, the toggle levers 57 and are swung toward the axis of the tube 15. Thus, as the handle-lever 55 is moved downwardly, the slide member 40 is forced upwardly away from the boss 12 at the upper end of the base tube 10. Now, since the inclined pawl-plate 48 is in firm dogging engagement with the support tube 15, the latter is slid or extended upwardly so as to raise the drill 25 toward the beam 33.
Continued downward movement of the operating handle 55 causes the pivot pin 58 to move across center, that is, beyond an imaginary line passing through the pivot pins 50 and 61. Thus, the slide member 40 is retained in its upwardly adjusted position. If further upward movement of the tube 15 and drill 25 is necessary to di rect the drill bit 29 into the beam 33, the drill is retained in its upper position by means of the handle 27 while the operating handle 55 is raised. As the handle is lifted, the toggle levers 60, 57 act to draw the slide member 40 downwardly until it comes to rest upon the boss 12. During this movement of the slide member 40, the pawl-plate 48 is caused to assume a position in which it extends normal to the axis of the tube 15 so as to disengage the latter to permit lowering of the slide member relative to the holder tube.
When the slide member 40 is thus lowered to its full extent it may again be raised to feed the tube 15 and drill 25 upwardly through another predetermined increment of movement by simply depressing the operating I handle 55. Vertical reciprocation of the slide member 49 intermittently advances the drill upwardly toward the beam 33.
By this procedure, the rotating drill bit 29 is caused to penetrate the beam 33 and to drill a hole therein and it is to be particularly noted that during such drilling the portable drill is supported entirely by the extensible device which is, in effect, a post or column. Consequently, the workman is relieved of the laborious and hazardous task of manually supporting the portable drill and forcing it upwardly while guiding the drill bit in a true vertical path of movement. It is important to note that due to the relatively long operating handle 55 and the particular arrangement of the toggle levers 57 and 60 of the jack-like operating means, maximum mechanical advantage is attained so that the raising of the drill is accomplished with a minimum of physical effort on the part of the operator. Moreover, greater upward force is developed through the operating lever system than has hitherto been possible so that the drilling operation is greatly expedited and drills of larger capacity may be employed as the situation requires. In addition, the drill is supported in a stable manner so that the drill bit may be accurately guided and any tendency of the drill bit to tilt or Wobble during the drilling operation is wholly avoided. As previously explained, the operating means is located adjacent the portable drill so that the drilling operation is conveniently and positively controlled by the workman who may be positioned on a ladder or other support above the floor.
Assuming'that a drilling operation has been completed, the drill bit 29 is withdrawn from the beam 33 by simply releasing the holder tube 15 to allow it to descend under the influence of gravity. This is accomplished by simply tilting the pawl-plate or dog 48 from its inclined position to a plane extending normal to the axis of the tube, as indicated by the broken lines in Fig. 4. The pawl-plate is easily pivoted on the fulcrum lip 45 by depressing its laterally projecting end as shown.
In order to attain even more positive advancing of the drill toward the work, the pawl means may be provided in multiple, for example, a slide member 40' of the type shown in Fig. 6 may be utilized, this member carrying at least two of the pawl-plates 48 in its transverse openings 44' for engaging the holder tube 15.
My extensible drill supporting fixture or device has thus far been described as adapted to rest upon a floor. It is to be understood, however, that the length of the device may be varied to meet the different conditions. For example, by making the base tube 10 relatively short the device may be utilized to advantage by setting it up upon the top of a ladder, scaffold or other elevated support. It will also be apparent that the holder device may be applied to use in drilling horizontal holes in vertical walls and other structural members, in which case the device is placed in horizontal position with its base plate 11 abutting any fixed vertical surface. As an additional feature, the present drill supporting and operating device is adapted for use with portable drills of a large variety of makes and sizes, the segmental ring 20, 21, 22 being readily adjustable for this purpose.
In accordance with the provisions of the patent statutes, I have herein described the principle of operation of my invention, together with the devices which I now consider to represent the best embodiments thereof, but I desire to have it understood that the devices shown are only illustrative and that the invention may be carried out by modified means.
I claim as my invention:
A drill supporting and operating device, comprising: a vertical base tube having a base plate at its lower end adapted to rest upon a floor or like fixed support, said base tube having spaced ears at a side thereof; a holder tube telescopically slidable in said base tube for axial sliding movement relative thereto to extended and retracted positions, said holder tube providing a support for a drill; a slide member surrounding said holder tube above said base tube and having spaced cars at a side thereof; a handle lever having an end pivotally connected between said ears of said slide member and having an ear projecting transversely thereof, said last-named ear providing a first toggle lever; a second toggle lever having its ends pivotally connected to said first toggle lever and said ears of said base tube, downward pivotal movement of said handle lever toward said base tube acting through said toggle levers to slide said slide member upwardly away from said base tube; and a one-way pawl plate pivoted on said slide member and normally engaged with said holder tube and operative to slide the latter to an extended position upon downward pivotal movement of said handle lever, said pawl plate having an aperture of slightly larger diameter than said holder tube and through which the latter extends, said pawl plate normally being in an inclined position to cause diagonally opposite edges of its said aperture to engage opposite sides of said holder tube, said slide member having a lip providing a fulcrum against which an end of said pawl plate rests and upon which the pawl plate can be pivoted to a plane extending substantially normal to the axis of said holder tube so as to allow axial sliding movement of said holder member relative to said slide member to its retracted position, the pivotal connection, of said first and second toggle levers being movable across the center between the pivotal connection of said first toggle lever and said slide member and the pivotal connection of said second toggle lever and said base tube so as to retain said slide member and said holder tube in their extended position, the lower end of said slide member being engageable with the upper end of said base tube to limit the downward sliding movement of said slide member.
References Cited in the file of this patent UNITED STATES PATENTS 2,140,854 Schnebly Dec. 20, 1938 2,227,397 Lucker Dec. 31, 1940 2,405,110 Bullock Aug. 6, 1946 2,629,267 Hart Feb. 24, 1953