US3884593A

US3884593A - Apparatus for drilling aligned holes

Info

Publication number: US3884593A
Application number: US475825A
Authority: US
Inventors: Virgil F Christoffer
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-06-03
Filing date: 1974-06-03
Publication date: 1975-05-20
Anticipated expiration: 1992-05-20

Abstract

Apparatus to be secured in the chuck of a portable power drill, for drilling holes in spaced panels, includes an elongated bit extension carrying a housing, longitudinally slidable and rotatable on the extension shaft. The housing is urged toward the leading end of the extension shaft, which carries the drilling bit. The housing includes a nose cone for centering the housing and bit extension in the first drilled hole; and the housing carries level indicating devices for either plumbing or leveling the bit extension to assure vertical or horizontal alignment of the second drilled hole. An anchor device secured to the power drill, prevents rotation of the housing relative to the drill.

Description

United States Patent 1 Christoffer APPARATUS FOR DRILLING ALIGNED HOLES Inventor: Virgil F. Christofler, 1603 8.

Cooper, Arlington, Tex. 76010 Filed: June 3, 1974 Appl. N0.: 475,825

References Cited UNITED STATES PATENTS 11/1886 Traut 33/334 2/l957 Vogt 33/347 12/196] Russell 408/80 [45] May 20, 1975 Primary Examiner-Gil Weidenfeld Attorney, Agent, or Firm-Peter J. Murphy 5 7] ABSTRACT Apparatus to be secured in the chuck of a portable power drill, for drilling holes in spaced panels, includes an elongated bit extension carrying a housing, longitudinally slidable and rotatable on the extension shaft. The housing is urged toward the leading end of the extension shaft, which carries the drilling bit. The housing includes a nose cone for centering the housing and bit extension in the first drilled hole; and the housing carries level indicating devices for either plumbing or leveling the bit extension to assure vertical or horizontal alignment of the second drilled hole. An anchor device secured to the power drill, prevents rotation of the housing relative to the drill.

10 Claims, 5 Drawing Figures 1 APPARATUS FOR DRILLING ALIGNED HOLES BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to apparatus for drilling either plumbed or leveled holes in closely spaced panels; and more particularly to apparatus which is attachable to a portable power drill for that purpose.

According to the invention, apparatus is provided which is conveniently attachable to portable power drills, such as would be used by electricians or carpenters for example, to enable the drilling of perfectly aligned holes in closely spaced panels. One application would be in the drilling of horizontal holes through near and far panels of either an interior or exterior partition or wall of a building. Another application is drilling either upward or downward through the spaced panels which define the ceiling and floor, between floors of a building. Another application is the drilling of holes upwardly through the eave of a home for example where the lower panel is horizontal and the upper panel is the inclined roof of the home. In these situations of horizontal drilling, it is frequently desirable or necessary that the holes in the first and second partitions be perfectly level. Similarly, in the applications of vertical drilling it may be either necessary or desirable that the holes in the two spaced partitions be perfectly plumbed.

It is desirable then for craftsmen such as electricians and carpenters to have apparatus which is available for this purpose. Furthermore it is desirable that such apparatus be in the form of an attachment for conventional portable power drills, where the attachment can be readily mounted on the portable power drills for use as necessary, and wherein the attachment is readily re movable so that the drills may be used in conventional fashion for other drilling operations or for other uses.

Accordingly it is a principal object of this invention to provide apparatus to enable the drilling of perfectly level holes in structures containing closely spaced generally vertical panels, and for drilling perfectly plumbed holes in structures including generally horizontal closely spaced panels.

Another object of this invention is to provide such apparatus in the form of an attachment which is readily mounted on or demounted from a conventional portable power drill.

A further object of this invention is to provide such an attachment which is simple and rugged in construction to enable manufacture at a reasonable cost and to be sufficiently durable for use by construction craftsmen.

Still another object of this invention is to provide such an attachment which is suitable for use in many applications of either horizontal or vertical drilling.

These objects are accomplished in apparatus which comprises generally an elongated shaft defining a drill bit extension, having stop means at each end, and a housing mounted on said shaft for relative sliding and rotational movement. An elongated coiled compression spring is disposed on the shaft, between the housing and at its trailing end, for continuously urging said housing along said shaft toward its leading end. At least one level indicator is mounted on said housing in position to enable the drill operator to maintain said bit extension shaft in a selected orientation during vertical drilling.

More particularly the housing has means mounted on its leading end for centering the housing and extension shaft in the first hole drilled for the purpose of aligning the apparatus for the drilling of the second hole.

Also more particularly the apparatus includes means for preventing rotation of the housing relative to the portable drill, to enable observation of the desired level indicator during the drilling, particularly. of the hole in the nearer panel,

The novel features and the advantages of the invention, as well as additional objects thereof, will be understood more fully from the following description when read in connection with the accompanying drawings.

DRAWINGS FIG. 1 is an elevation view of an assembled portable drill and level drilling apparatus according to the invention, in use drilling upward through the eave of a buildmg;

FIG. 2 is a detail view, from the plane 2-2 of FIG. I, showing the face of the housing centering cone;

FIG. 3 is an elevation view of an assembly similar to that of FIG. 1, in use drilling vertically downward, and showing means for preventing rotation of the attachment housing relative to the drill; and

FIGS. 4 and 5 are detail views of a grommet for the antirotation assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the following specification reference is made to a drill bit extension which is a commercially available device including an elongated shaft or shank being configured at one end to be received in the driving chuck of a conventional portable power drill and having its own chuck at the other end, referred to as a leading end, for securing any type of drill bit. Such a drill bit extension forms a part of the apparatus according to this invention.

Closely spaced panels" as defined in this specification means panels which are close enough so that aligned holes can be drilled through them in a single operation; and the spacing of the panels would be limited to the practical spacing which would normally be accommodated by conventional drill bit extensions, either single extensions or extensions coupled in series. Examples of structures having such closely spaced panels are vertical walls or partitions having near and far panels in relation to the position of the drilling operator; ceiling-floor structures wherein the operator may be drilling downward first through the floor panel and secondly through the ceiling panel, or drilling upward first through the ceiling panel and secondly through the floor panel. Another example is the drilling upwards through the eave of a residence illustrated in FIG. 1, wherein the operator is drilling upward first through the horizontal lower eave panel and secondly through the inclined roof panel including the shingles. In this operation, the spacing between panels could be l2 inches or more, for example.

The level indicators" which are referred to in this specification are illustrated as flat cylindrical units which, in horizontal orientation, have a fluid supported bubble which is centered at the upper convex wall when the unit is perfectly horizontal. In normal use, these level indicators are viewed from the top, and indicate tilting in any direction from the horizontal plane.

Referring now to the drawings, FIG. I shows the assembly of a portable power drill I and a drilling attachment 20. This drill may be a /2 inch drill, for example. and includes a pistol grip type housing II, a chuck l2, and a trigger switch 13.

The attachment includes an elongated shaft 21 having a collar 22 non-rotatably fixed adjacent to its trailing end, which is the end received in the drill chuck, and having a chuck 23 at its leading end for receiving and locking a drill bit. A housing 24 is mounted on the shaft 21 to slide longitudinally on the shaft and to be rotatable on the shaft; and the housing is provided with suitable bearing means so that the housing and shaft will be maintained in perfect alignment. The housing includes a centering cone 25 at its leading end, provided with a frusto-conical surface, and this ccntering cone is provided with a flat 26 in a plane parallel with the shaft axis, the purpose of which will be described subsequently. The housing is also provided with a transverse shelf 27 at its trailing end disposed in a plane perpendicular to the shaft axis, the purpose of which will also be described subsequently.

An elongated helical compression spring 30 is disposed about the shaft 21 between the housing 24 and an annular bearing member 31 rotatable on the shaft and relative to the fixed collar 22. This spring normally urges the housing 24 forward against cushioning washers 32 disposed on the shaft adjacent to the chuck 23. In drilling operations, the housing 24 follows the bit until the cone centers itself in the first hole; and the spring maintains the cone in the first hole as the bit advances to the second panel.

The illustrated drill bit mounted in the extension chuck 23 is a hole saw 35 having a cylindrical saw for drilling a 2 k inch diameter hole, for example, and having a pilot bit 36 for drilling a leading pilot or centering hole to maintain alignment of the hole saw.

As illustrated in FIG. 1, the housing 24 has mounted thereon three

level indicators

41, 42 and 43. The

level indiactors

41 and 42 are mounted on opposite flat walls of the housing 24, which are disposed in planes parallel with the axis of the extension shaft 2]. These indicators are shown on two opposite sides of the housing, by way of example only, to be used in horizontal drilling to level the extension shaft 21 when drilling horizontal holes through spaced, generally vertical panels. The level indicator 43 is mounted on the top or leading face of the shelf 27; and is mounted in alignment with a hole 28 formed in the shelf. This level indicator 43 is for particular use in the vertically upward drilling situation illustrated in FIG. I. As mentioned, the level indicators are normally viewed from the top; however in this application it is necessary that the level be viewed from the bottom; and accordingly the housing of this particular indicator 43 is transparent to enable the operator to view the level indicator through the hole 23 to maintain the extension shaft perfectly plumb.

FIG. 3 of the drawing shows the above described assembly of drill l0 and attachment 20 in orientation for drilling downward through spaced horizontal panels. As best seen in FIG. 3 there is attached to the housing 24 a transverse arm 49 projecting beyond opposite sides of the housing and to which is attached an antirotation assembly 50. This antirotation assembly includes a pair of

link chains

51 and 52 having

respective S links

53 and 54 for rotatably coupling the chains to a grommet assembly 55. The

chains

51 and 52 also include

respective spring clips

57 and 58 for securing the opposite ends of the chains to respective ends of the arm 49.

The grommet assembly is an annular assembly consisting of two

semi-circular grommet halves

61 and 62 having confronting ends spaced from each other and joined together by pins 63 which are rigidly coupled to the confronting ends. The pins 63 provide journals for the

chain links

53 and 54 to enable the grommet assembly to roll over the nose portion of the drill housing I l, with the links being maintained in spaced relation to the drill housing to prevent marring of the housing. The grommet halves have a cross-section defined by a flat portion 64 and adjacent rib 65, with the remainder of the cross-section presenting a rounded surface. This configuration enables the grommet assembly to be readily rolled onto the nose portion of the drill, in the direction of the arrow 56, and to resist reverse rolling off the nose portion of the drill housing when the flat grommet surface 64 lies adjacent to the housing.

The purpose of this antirotation assembly is to limit rotation of the housing 24 with the extension shaft 2], and relative to the drill, so that an appropriate level indicator may be observed continuously by the operator while drilling the hole in the first panel for example as illustrated in FIG. 3.

For downward drilling, as in FIG. 3, the trailing face of the housing shelf 27 is visible to the operator; and for plumbing the assembly for this operation, a level indicator 44 is secured to the trailing face of the shelf; and for this purpose the shelf and indicator may have coacting magnetic means so that the indicator will be readily retained on the shelf in overlying relation to the hole 28, yet readily removable to enable use of indicator 43 for the upward drilling as in FIG. 1.

OPERATION The operation of the above described drill and attachment will now be described with respect to several drilling applications.

FIG. 1 illustrates fragmentarily a portion of a residence structure including an exterior wall panel 66, a horizontal eave panel 67 and an inclined roof panel 68. The illustrated application is that of drilling plumbed holes through the cave panel 67 and roof panel 68 which are very close to the wall panel 66, for the purpose of accommodating a mast for bringing electric power lines down to a meter base. In this application, a meter base is to be mounted on the wall panel 66 for supporting a meter; and a mast fabricated of 2 inch rigid conduit having a 2 inches OD extends through the roof and is threaded into the meter base. In this ap plication then, plumbed holes must be drilled very close to the exterior surface of the wall panel 66.

For this use the fiat 26 on the centering cone 25 permits the hole in the eave panel 67 to be drilled as close as desired to the wall panel 66; and this flat also prevents rotation of the housing 24 to enable the continuous observation of the level indicator 43 during drilling of the first hole. The operator will be viewing the level indicator 43 through the hole 28 in the direction of the broken arrow 45. For this application, the hole saw 35 would preferably have an OD of 2 /2 inches; and the distance between the centering cone flat 26 and the axis of the shaft 21 would be I A inches so that the hole could be drilled, if desired, perfectly flush with the wall panel 66. In FIG. 1 the hole in the cave panel is slightly spaced from the wall panel and the operator drills this first hole maintaining the assembly plumb by viewing the level indicator 43 as indicated. After the hole saw penetrates the cave panel. the centering cone 25 will center itself in the first hole and the operator will maintain the plumb condition until the pilot bit 36 penetrates the roof panel 68. Once this penetration occurs the alignment is assured with the centering cone being maintained centered in the cave hole by the action of the spring 30. The end result will be an absolutely vertical mast which is of course desirable from an aesthetic standpoint. It should be noted that where a hole is to be drilled through an inclined panel such as in roof panel 68, the pilot bit 36 should be sufficiently long to penetrate the panel prior to initial engagement by the cylindrical hole saw.

A similar application would be the drilling of plumbed holes upwardly through spaced ceiling and floor panels; and if the ceiling panel hole is to be perfectly flush with an adjacent wall surface, the cone flat 26 would be disposed against such wall surface.

in upward vertical drilling, away from a vertical wall surface. it would be necessary to employ the antirotation assembly 50 for the drilling of the first hole through a ceiling panel for example to enable continuous viewing of the indicator 43; and the centering cone 25 would then align the apparatus for the drilling of the second hole through the floor panel.

In the downward vertical drilling situation illustrated in FIG. 3, the drilling is through a first floor panel 70, for example, and a second ceiling panel 71. For this operation the antirotation assembly 50 limits rotation of the housing to enable continuous viewing of the level indicator 44 during the drilling of both the first and second holes. After drilling of the first hole in the floor panel 70, of course, the centering cone 25 centers the apparatus to assure plumb alignment of the two holes.

For the drilling of holes flush or substantially flush with a vertical wall panel for example, the antirotation assembly 50 need not be used, and the cone flat 26 will function to prevent housing rotation and permit continuous viewing of the indicator 44.

For horizontal drilling through a wall partition, for example, away from any floor or ceiling panel, the antirotation assembly 50 would be used to limit housing rotation for the drilling of the first hole. For this drilling either of the

indicators

41 or 42 might be used depending on which side of the housing is exposed to the drill operator. if the indicator 41 is being viewed by the operator he will of course view the indicator in the direction of the broken arrow 46.

For the drilling of horizontally aligned holes adjacent to a floor panel for example, the flat 26 will confront the floor panel and the indicator 41 will be facing upward to be viewed by the operator. Again the cone flat will prevent rotation of the housing during this drilling application.

For the drilling of horizontally aligned holes adjacent to a ceiling panel, the flat 26 will be placed adjacent to the ceiling panel; and in this situation, none of the level indicators illustrated will be observable by the operator.

In a situation where horizontally aligned holes are being drilled at a relatively high level but not adjacent to a ceiling panel. the antirotation assembly must be used to prevent housing rotation and the upward facing indicator could be observed by an operator standing beneath or beside the drilling apparatus through the use of a mirror or reflector which may be suitably mounted on the housing adjacent to the indicator.

The above described apparatus may also be used for the drilling of holes in generally parallel panels which are inclined relative to the axis of the drilled holes. In this situation, the pilot bit 36 must be sufficiently long, as above mentioned, to engage and penetrate each panel in sequence prior to initial engagement by the hole saw; and additionally the pilot bit should engage and penetrate the second panel while the hole saw re mains centered in the first hole to assure alignment of the two holes.

In an alternative form of apparatus, the housing shelf 21 could be hingedly mounted on the housing 24 in a manner to assume two indexed positions, one being parallel to the shaft axis and the other being perpendicular to the shaft axis. The shelf so mounted and carrying a level indicator, would provide a single level indicator which could be used for either vertical drilling or horizontal drilling.

What has been described is a novel apparatus for drilling perfectly aligned holes in spaced panels, that is holes which are either perfectly level in a horizontal plane or perfectly plumbed along a vertical axis. A particular feature of this invention is that it is in the form of apparatus for attachment to conventional portable power drills, enabling use of the drills in a conventional manner and enabling use of the drill to drill the particular level or plumbed holes as described. Another feature of the invention is that it is simple and rugged in construction providing durability and reliability in use. Another feature of the invention is the centering cone of the housing which enables precise centering of the apparatus in the first hole while drilling the second hole; and which also restricts rotation of the housing to enable observation of the level indicators. Still another feature of the invention is the configuration of the nose cone being provided with a flat to enable drilling of holes flush with a lateral panel surface, in situations of course where relatively large diameter holes are being drilled. Still another feature of the apparatus is the provision of a detachable antirotation device by means of which rotation of the housing relative to the extension shaft can be prevented by a simple securing device secured to the nose of the power drill; and which is secured thereto without marring the power drill housing.

While the preferred embodiment of the invention has been illustrated and described, it will be understood by those skilled in the art that changes and modifications may be resorted to without departing from the spirit and scope of the invention.

What is claimed is:

1. Apparatus for use with a portable power drill for drilling aligned holes in closely spaced panels, comprising:

an elongated shaft defining a drill bit extension having stop means at each end; a housing rotatably and slidably mounted on said shaft for relative sliding and rotational movement;

an elongated coiled compression spring, disposed on said shaft, between said housing and the shaft stop means at the trailing end of the shaft, for continuously urging said housing along said shaft toward engagement with the shaft stop means at the leading end thereof;

at least one level indicator means mounted on said housing to enable the drill operator to level said bit extension shaft in a selected orientation for drilling.

2. Apparatus as set forth in claim 1 said at least one level indicator means including a first indicator means mounted on said housing in position to enable the drill operator to plumb said bit extension shaft during vertical drilling, and a second indicator means mounted on said housing to enable the drill operator to level said bit extension shaft during horizontal drilling.

3. Apparatus as set forth in claim 1 centering means mounted on said housing at its leading end; said centering means defining a conical structure having its axis coinciding with the rotational axis of said extension shaft, with its smaller end being the leading end.

4. Apparatus as set forth in claim 3 a bit for drilling a relatively large hole secured to the leading end of said bit extension; said centering means defining a flat surface; disposed in a plane parallel to the bit extension axis and spaced therefrom a distance corresponding to the drill bit radius.

5. Apparatus as set forth in claim 1 an anti-rotation assembly for said apparatus comprising a pair of elongated flexible members of equal length, annular elastic grommet means dimensioned to be stretched over the nose portion of the portable drill, means coupling one end of said respective flexible members to said grommet means at opposite sides thereof, and means on said housing for coupling one end of said respective flexible members at opposite sides thereof.

6. Apparatus as set forth in claim 5 said annular grommet means comprising two generally semi-circular elastic members, with their confronting ends being spaced from each other and being coupled by coupling pins rigidly coupling the confronting ends thereof; and said coupling pins defining journal members surrounded by links at the end of the flexible members to enable rolling of the grommet means relative to the flexible members and the nose of the drill.

7. Apparatus as set forth in claim 6 said elastic members having cross-sectional shaped means to enable unrestricted rolling of said grommet means over the nose of the drill in one direction and, which restricts the rolling of said grommet means in the reverse direction.

8. Apparatus as set forth in claim 1 said housing having a transverse shelf projecting therefrom, provided with a viewing hole; level indicator means including a first level indicator mounted on the leading side of said shelf overlying said viewing hole, for normal viewing from the leading side, and having a transparent base to enable viewing from the trailing or bottom side through said viewing hole during upward vertical drilling.

9. Apparatus as set forth in claim 8 said shelf having means for detachably mounting a second level indicator on the trailing side thereof, for viewing from the trailing side for downward vertical drilling.

10. Apparatus as set forth in claim 1 said housing having at least one planar wall parallel to the axis of said extension shaft; and said level indicator means including a first level indicator mounted on said planar wall for leveling said bit extension during horizontal drilling.

1' IF I l

Claims

1. Apparatus for use with a portable power drill for drilling aligned holes in closely spaced panels, comprising: an elongated shaft defining a drill bit extension having stop means at each end; a housing rotatably and slidably mounted on said shaft for relative sliding and rotational movement; an elongated coiled compression spring, disposed on said shaft, between said housing and the shaft stop means at the trailing end of the shaft, for continuously urging said housing along said shaft toward engagement with the shaft stop means at the leading end thereof; at least one level indicator means mounted on said housing to enable the drill operator to level said bit extension shaft in a selected orientation for drilling.