MXPA01009235A - Self-adhering drill and cutter - Google Patents

Abstract

The present invention is a low profile self-adhering drill (10) having a feed mechanism (16) having an axis of rotation, which is generally perpendicular to the axis of rotation of the drill motor (14). The feed mechanism (16) includes a quill housing (40) which houses a quill (60). A spindle (110) is disposed within the quill (60) and rotates about the travel axis of the quill (60) relative to the quill (60) and is moveable along the axis with the quill (60). A rack (72) on the quill (60) is parallel to the travel axis and engages a feed gear (80) such that when the feed gear (80) is rotated the rack (72) and quill (60) move along the travel axis.

Description

SUCH AD RAD O R AND C O R T AD O AD H E R E NT E BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention relates to magnetic base drills that magnetically adhere to metal parts. More specifically, this invention relates to a smaller or miniature magnetic base drill for use in confined spaces or for smaller tasks.

DESCRIPTION OF THE PRIOR ART Magnetic base drills are used for large metal parts that can not be easily carried into a drill press and where a conventional hand drill would be insufficient. However, the magnetic drills of the prior art, although portable, are still very large and cumbersome. Therefore, what is needed is a lightweight, more portable magnetic base drill.

BRIEF DESCRIPTION OF THE DRAWINGS Other advantages of the present invention will be readily appreciated by reference to the following detailed description considered in connection with the accompanying drawings in which: Figure 1 is a perspective view of the present invention. Figure 2 is a side view of the present invention. Figure 3 is an exploded view of a feeding mechanism of the present invention. Figure 4 is a bottom view of the feeding mechanism of the present invention. Figure 5 is a cross-sectional view taken along line 5-5 of Figure 4 with the feeding mechanism in the fully retracted position. Figure 6 is a view similar to that of Figure 5, but with the feeding mechanism in the fully extended position. Figure 7 is a side view of a cutting tool of the present invention. Figure 8 is an end view of the cutting tool shown in Figure 7. And Figure 9 is a cross-sectional view taken along line 9-9 of Figure 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to Figures 1 and 2, a low profile self-adhesive magnetic base drill is generally shown at 10. Drill 10 has a box 12, or housing, which houses a motor 14 that engages with driving a feeding mechanism 16 with a cutting tool 18. The feeding mechanism 16 advances the cutting tool 18 towards a part. A magnetic base 20 is attached to the housing 12 and is used to anchor the drill 10 to the metal part. Although a magnetic base 20 is illustrated, other self-adhesive bases could be used, for example, a vacuum base. The feeding mechanism 16 is mounted within an end 21 of the housing 12 and has a first axis of rotation A, see FIGS. 2 and 4. The motor 14 is mounted at an end 22 opposite the feed mechanism 16, or the elongated main portion of the drill 10, and has a second axis of rotation B angled to the first axis A. The first and second axes A and B are at a generally straight angle that allows the drill 10 to achieve a low profile. The motor 14 is coupled to the gear mechanism 16 by gears 24 or in any other suitable manner.

In the best mode of the present invention, a modified 3/8 inch Right Angle Drill is used De-Walt Model DW160 which operates at 110 volts and 3.6 amps and rotates the cutting tool at 1200 rpm. The operator of the drill uses the main portion 22 of the drill 10 as a handle. A switch of the drill 26 is placed on the underside of the drill 10 to drive the motor 14 when an electrical wire 30 is plugged into an electrical source. Although an electric motor is described, it is to be understood that a driller with a pneumatic motor or any other drive mechanism may also be used. The magnetic base 20 is a rectangular structure having a flat surface 32 for contacting the part W. Base 20 contains electrically activated magnetic coils (not shown) that are attracted to metals that have magnetic properties when current flows through the coils. In this application when "metallic piece" is used, it is meant to mean any piece capable of being attracted by a magnet. A switch 34 connects the electric wire 30 to the magnetic coils so that when the electric wire 30 is connected to an electrical source and the switch 34 is put in an "on" position, the magnetic base 20 will be anchored securely to the metal part W. In the preferred embodiment, the switch 26 for driving the drill 10 is connected to the magnetic base switch 34 in such a way as to prevent the electric motor 14 from being moved. unless the magnetic base 20 is connected. This ensures that the drill 10 can not operate without first properly securing the piece W. The magnetic base 20 is attached to the housing 12 by a plurality of supports 36 so that the base 20 is generally parallel with a main portion 22. of the drill 10. If a commercially available drill such as the aforementioned DeWalt drill is being used, the union holes in the housing can be used to join the magnetic base 20 to the drill through supports 36. The mechanism of Supply 16, see Figure 3, includes a hollow shaft housing 40 that is partially received at the end 21 of the housing 12 and is the structural component that houses the components used to couple the cutting tool 18 to the engine 14. These components , explained below, also allow to advance and retract the cutting tool 18 along the first axis A. In addition, it should be appreciated by the following explanation The feeding mechanism of the present invention eliminates several components traditionally used in such feeding mechanisms, thus giving rise to a more compact design. This compact design is what, in part, makes it possible to achieve the small low profile design of the present invention. Referring now to Figures 3 and 4, the hollow shaft tubular housing 40 has a circular cross section and includes inner surfaces 42 and outer 44. The shaft of the hollow shaft housing 40 is concentric with the first axis A. A housing tubular feed gear 46 is fixed transversely to a lower portion 48 of the outer surface 44 and also has a circular cross-section. The inner surface 42 of the hollow shaft housing 40 has a linear groove 50, which is well seen in Figure 4, with a rectangular cross section that is parallel with the first shaft and running the entire length of the hollow shaft housing 40. A rectangular hole 54 passes from the interior surface 42 of the hollow shaft housing 40 to the interior 56 of the feed gear housing 46 where the linear slot 50 intersects the interior 56. A tubular hollow shaft 60 having a cross section circular is arranged with the hollow shaft housing 40.

The axis of the hollow shaft 60 is also concentric with the first axis A. The hollow shaft 60 has an inner surface 62 and an outer surface 64 which is in sliding engagement with the inner surface 42 of the hollow shaft housing 40. The outer surface 64 has an elongated recess 66 in outer surface 64 running parallel to first axis A. A pair of grooves 70 extends transversely to elongated recess 66 in outer surface 64. A rack 72, having a pair of tabs 74 which complement the grooves 70, is received in the elongated recess 66 and the grooves 70. Epoxy is used to fix the rack 72 within the elongated recess 66 and the grooves 70, although it is possible to use other joining means. The tabs 74 and grooves 70 help to ensure that the rack 72 does not come loose from the hollow shaft 60 when the hollow shaft 60 is translated along the first axis A. The rack 72 has a plurality of teeth 76 projecting from the outer surface 64 of the hollow shaft 60. These teeth 76 are received within the linear slot 50 of the hollow shaft housing 40 and extend through the rectangular hole 54 and to the feed gear housing. 46. A feed gear 80 having a plurality of radially outwardly extending teeth 82 is disposed within the feed gear housing 46. The teeth of the feed gear 82 engage teeth 76 in the rack 72 so that when the The feed gear 80 is rotated about its axis, the rack 72 and the hollow shaft 60 rise and fall along the first axis A. The feed gear 80 has a first end 84 which is adjacent one end 86 of the power gear housing 46. A retaining washer 88 is fastened to the first end 84 to assist in laterally positioning the feed gear 80 within the feed gear housing 46. The feed gear 80 has a second end 92 and a intermediate portion 94 interposed between the first ends 84 and, second 92. The intermediate portion 94 includes an annular groove (not shown) that is ad lying to another end 96 of the feed in-gear housing 46 which receives a spring ring 98. The spring ring 98 in conjunction with the retaining washer 88 laterally places the feed gear 80 so that the feed gear 80 does not move laterally along its axis. A handle 100 is attached to the feed gear 80 between the intermediate portion 94 and the second end 92 at an angle to the axis of the feed gear. A distal end 102 of the handle 100 has a button 104 that when rotated about the axis of the feed gear moves the hollow shaft 60 along the first axis A. Returning to figure 3, a spindle 110 is disposed within the hollow shaft 60 and has a shaft coaxial with the first axis A. The spindle 110 has upper portions 112 and lower 114 and inner surfaces 116 and outer 118. The outer surface 118 is in engagement with the inner surface 62 of the hollow shaft 60. The feeding mechanism 16 differs from prior art mechanisms in that the hollow shaft 60 is made of brass and acts as the bearing between the hollow shaft steel housing 40 and the steel spindle 110. Typically, the hollow shaft is also of steel which It requires the use of bronze bushes between the hollow shaft housing and the hollow shaft and the spindle and hollow shaft. By constructing the hollow bronze shaft according to the present invention, two bronze bearings can be eliminated, thereby allowing a more compact feed mechanism. The spindle 110 has an annular groove 122 in the outer surface 118 of the upper 112 and lower portions 114 for receiving retaining rings 124 for fixing the spindle 110 to the hollow shaft 60. A metal thrust washer 126 and plastic 128 is interposed between the retaining ring 124 and the hollow shaft 60 in both upper 112 and lower 114. In this way, the hollow shaft 60 and the spindle 110 are coupled and can be moved together along the first axis A. The inner surface 116 of the upper portion 112 of the spindle 110 has a plurality of grooves 130 extending radially inwardly from and parallel to the first axis A. A shaft 134 having a shaft coaxial with the first axis A has a first end 136 coupled to the drive motor 14 of the drill 10. For the described DeWalt drill, the first end 136 is screwed onto a shaft threaded coupling to motor 14. Shaft exterior 134 has grooves 138 extending radially outwardly and parallel to first axis A. Shaft grooves 138 slidably engage inner grooves 130 of spindle 110. In this manner, the shaft 134 rotatably drives the spindle 110 when the motor 14 is driven while allowing the spindle 110 to rise and fall along the first axis A. The inner cylindrical surface 11 6 has a diameter 140, 142 in upper portions 112 and lower 114 and a larger diameter 146 along a length of inner surface 116. A second end 150 of shaft 134 includes a tope 152 to limit the travel of the spindle 110 along the first axis A. The stop 152 is positioned very close to the larger diameter 146 so that when the stop 152 reaches the diameters 140, 142 of the upper portions 112 or lower 114, the stop 152 will contact a lip 156. , 158 on the inner surface 116. In the best mode of the present invention, a fastener is used for the stop and is offset from the first axis A. The feeding mechanism 16 is shown in its retracted and extended positions in the figures 5 and 6, respectively. To advance the cutting tool 18 to the extended position from the retracted position, the handle 100 is rotated about the axis of the feed gear. The feed gear 80 rotates about its axis thus moving the rack 72 downwards and parallel to the first axis A. The rack 72 moves the hollow shaft 60 and the spindle 110 which is fixed to the hollow shaft 60 by retaining rings 124 The spindle 110 slides down along grooves 130, 138 when the shaft 134 rotatably moves the spindle 110 and the cutting tool 18. The spindle 110 and the cutting tool 18 extend fully when the stop 152 engages. the lip 156 on the inner surface 116 of the upper portion 112 of the spindle 110.

To remove the cutting tool 18 from the extended position, the handle 100 is rotated about the axis of the feed gear in an opposite direction, thereby moving the components of the feed mechanism along the first axis A in the direction contrary. The spindle 110 and the cutting tool 18 are fully retracted when the stop 152 engages the lip 158 on the inner surface 116 of the lower portion 114. It has been found that the typical cutting tool geometries are inadequate when combined with the driller and the feeding mechanism of the present invention. Therefore, the cutting tool of the present invention is specially adapted to be used with the compact design of the drill of the present invention. Specifically, the various cutting angles of previously known tools have been changed and a taper has been added to the cutting portion of the tool as explained in more detail below. With reference to Figures 6 and 7, the lower portion 114 of the spindle 110 has a hole 170 along the first axis A with a pin 172 offset and transverse to the first axis A. The hole 170 is adapted to receive a spike portion 180 of the cutting tool 18. The shank portion 180 has a flat portion 174 leading to an annular recess 175 in a radial portion of the perimeter of the shank portion 180. The cutting tool 18 is inserted into the hole 170 aligning the flat part 174 with the pin 172 so that the cutting tool 18 can be inserted into the hole 170. To lock the cutting tool 18 in the hole 170, the cutting tool 18 is rotated so that the pin 172 is received within the annular recess 175. A rubber seal 176 or O-ring is received within an annular groove 178 in the spigot portion 180 to prevent 170 residues from entering the hole that would make it more difficult to extract it. Ion of the cutting tool 18 of the hole 170. With reference to FIGS. 7-9, the cutting tool 18 has a shank portion 180 and a cutting portion 182 extending from the shank portion 180 along the first Axis A. The cutting portion 182 includes a cutting surface 184 and inner surfaces 185 and outer surfaces 186 that taper rearward toward the spike portion 180. The inner surface 185 of the cutting portion 182 tapers to the order of 0.254. 0.635 mm (0.010-0.025 inch) over its length, with a range of 0.406-0.508 mm (0.016-0.020 inch) being preferred. The outer surface 186 of the cutting portion 182 tapers in the order of 0.381-0.889 mm (0.015-0.035 inch) over its length, with a range of 0.508-0.609 mm (0.020-0.024 inch) being preferred. The inner and outer taper is necessary to prevent the joint when the hole is being machined by the cutting tool 18 in the part. The cutting surface 184 has a plurality of cutting teeth 200. In the described embodiment, each of the cutting teeth 200 has cutting edges 202, 204 and 206.

Those skilled in the art should appreciate that more or fewer cutting edges could be used. The cutting edges are inclined with respect to the horizontal plane. In the described embodiment, the outer cutting edge 204 has an angle B of the outer inclination angle, of the order of 5-15 °, with the angle 10 being preferred. An exterior angle of inclination typical of an ordinary cutter is approximately 35 °. The cutting edge 202 has an angle X, that is, a lower angle of inclination, of the order of 20-30, the angle of 25 ° being preferred. In a typical cutter, the angle is approximately 15 °. The inner cutting edge 206 has the same internal angle of inclination as the cutting edge 202. Due to these cutting edge geometries, the blade quickly stabilizes in the part. The outer cutting edges 204 initially cut the surface of the piece so that the cutting tool immediately seats in the intended area of the piece. After the outer cutting edges start cutting, the inner cutting edges 202 and 206 begin to cut and together form a track. The teeth 202, 204 and 206 continue to cut into the path until the hole is formed, leaving a thread in the cutting tool. When the cutting tool is removed, the screw 152 engages a thread ejector, not shown, to eject the thread. The outer surface 186 has a plurality of helical grooves 194 for channeling the chips away from the part. The angle a of the helix is of the order of 22-30 °, the angle of 25 ° being preferred in comparison, being 15 ° a typical angle of the ordinary cutters. The helical grooves 194 include grooves 196 to facilitate the discharge of chips. The angles of the cutting tool of the present invention ensure that the tool "bites" the part and does not slip or twist as would a prior art tool when used with the drill of the present invention. In addition, the angles also accommodate the reduced power, speed, and torque of the smaller drill and magnetic base of the present invention compared to the larger designs of the prior art. The invention has been described in an illustrative manner, and it is to be understood that the terminology employed is intended to be descriptive rather than limiting in nature. Obviously, many modifications and variations of the present invention are possible in the light of the foregoing ideas. Therefore, it is to be understood that within the scope of the appended claims, where the reference numbers are for the sake of convenience and are not in any way limiting, the invention may be implemented in a manner other than that specifically described. .

Claims (19)

Claims

1. A hollow shaft housing for mounting to the drill, said hollow shaft housing having an axis; a hollow shaft disposed within said hollow shaft housing and being in engagement with it, said hollow shaft being movable along said axis relative to said hollow shaft housing; a spindle disposed within said hollow shaft for attaching a tool, said spindle being in engagement with said hollow shaft and being able to rotate about said axis relative to said hollow shaft and being able to move along said axis with said hollow shaft; a feed gear supported in said hollow shaft housing; and a rack on said hollow shaft and parallel to said shaft for engagement with said feed gear such that when said feed gear is rotated, said rack and hollow shaft move along said axis.

2. The feeding mechanism set forth in claim 1, further comprising an axis for rotatingly moving said spindle about said axis, said shaft having grooves extending radially outward and parallel with said axis, and wherein said spindle further includes grooves that they extend radially inwardly and parallel with said shaft to engage slidably with said outer grooves of said shaft.

3. The feeding mechanism set forth in claim 2, wherein said spindle further includes an inner cylindrical surface having a diameter in upper and lower portions and a larger diameter than said diameter disposed between said first and second ends along a length of said inner cylindrical surface, and wherein said axis further includes a stop fixed to a portion of said axis to limit the advance of said spindle along said axis to said length.

4. The feeding mechanism of claim 3, wherein said stop includes a threaded body and a head portion, said shaft having a hole with internal thread, said threaded hole receiving said threaded body, said head portion being positioned within said larger diameter .

5. The feeding mechanism of claim 1, wherein said hollow shaft is made of brass, whereby said feeding mechanism is more compact.

6. The feeding mechanism of claim 1, wherein said spindle has a quick connection for quickly attaching and removing a blade.

7. A low profile self-adhesive drill including: a housing, - a feed mechanism having a first axis of rotation and mounted on said housing; an engine having a second axis of rotation at an angle to said first axis of rotation and being mounted in said housing, said motor being coupled to said supply mechanism for rotating and operating said supply mechanism; and a self-adhesive base attached to said housing for securely joining the drill to a piece; said feeding mechanism including a hollow shaft housing for mounting to the drill, said hollow shaft housing having an axis; a hollow shaft disposed within said hollow shaft housing and being in engagement with it, said hollow shaft being movable along said axis relative to said housing; a spindle disposed inside said hollow shaft to hold a tool, said spindle being in engagement with said hollow shaft and being able to rotate about said axis relative to said hollow shaft and being able to move along said axis with said hollow shaft; a feed gear supported in said hollow shaft housing; and a rack on said hollow shaft parallel to said shaft for engagement with said feed gear such that when said feed gear is rotated, said rack and hollow shaft move along said axis.

8. The low profile self-adhesive boring machine set out in claim 1, further including an axis for rotating said spindle about said axis, said axis having grooves extending radially outwardly and parallel with said axis, and wherein said spindle also includes grooves extending radially inwardly and parallel with said shaft to slidably engage said outer grooves of said shaft.

9. The low profile self-adhesive drilling machine set forth in claim 8, wherein said spindle further includes an inner cylindrical surface having a diameter in upper and lower portions and a diameter greater than said diameter disposed between said first and second ends along a length of said inner cylindrical surface, and wherein said axis further includes a stop fixed to a portion of said axis to limit the advance of said spindle along said axis to said length.

10. The low profile self-adhesive drilling machine set out in claim 9, wherein said stop includes a threaded body and a head portion, said axis having a hole with internal thread, said threaded hole receiving said threaded body, said head portion being placed within said greater diameter.

11. The low profile self-adhesive drilling machine of claim 7, wherein said hollow shaft is made of brass, whereby said feeding mechanism is more compact.

12. The low profile self-adhesive drilling machine of claim 7, wherein said spindle has a quick disconnect for quickly joining and removing a blade.

13. An annular cutting tool for use with a low profile self-tapping drill including: a spigot portion for attachment to the drill; a cutting portion extending from said pin along an axis and tapering from a cutting surface opposite said pin back toward said pin, said cutting surface forming a first cutting plane and a second cutting plane on top of said cutting surface. said first cutting plane, said planes being perpendicular to said axis; a plurality of helical grooves on an outer surface of said cutting portion for channeling the chips away from a part, said helical grooves having grooves through which they intersect said second cutting plane; a first cutting edge in said first cutting plane for making an initial cut in the piece, said first cutting edge having an angle of inclination above said first cutting plane towards said axis; and a second cutting edge in said second cutting plane for cutting the piece after having made said initial cutting, said second cutting circular edge having a greater inclination than the inclination angle of said first cutting edge.

14. The annular cutting tool of claim 13, wherein said first cutting edge has an angle of inclination of between 5 and 15 °.

15. The annular cutting tool of claim 13, wherein said first cutting edge has an angle of inclination of about 10 °.

16. The annular cutting tool of claim 13, wherein said second cutting edge has an in-clink angle of between 20 and 30 °.

17. The annular cutting tool of claim 13, wherein said second cutting edge has an angle of inclination of about 15 °.

18. The annular cutting tool of claim 13, wherein said helical groove has a helical angle of the order of 20 to 30 °.

19. The annular cutting tool of claim 13, wherein said helical groove has a helical angle of about 25 °.