Portable Tool Mount

Abstract

A wheeled cart which has provisions for mounting a surface working tool such as a drill for cutting holes in a floor of concrete or like material. A seat for a human operator is carried on a frame which is hinged to the cart and shaped to raise at least one wheel of the cart from the floor and to engage a frictional foot with the floor. The weights of the human operator and the cart are combined through mechanical advantage to effect a secure frictional relationship between the floor and the foot.

Description

BACKGROUND OF THE INVENTION

This invention relates to tool mounting arrangements and more particularly, although in its broader aspects not exclusively, to an improved portable drill mount arranged for drilling holes in floors.

In the construction of office buildings and the like, it is a common practice to pour concrete flooring around previously positioned electrical conduit. After the concrete floor is hardened, a hand-held tool is normally employed to drill holes in the floor in order to provide access to the embedded conduit. Using this construction technique, terminal boxes may be positioned wherever they are required after the needs of the building tenant have been determined.

Unfortunately, the use of hand-held drilling tools is time consuming and often dangerous. Should the core bit unexpectedly strike and adhere to an embedded reinforcing rod or the like, the torque and impact of the drilling tool bit may be turned against the operator, often causing injury. Even without such occurrences, these powerful tools are difficult and fatiguing to operate. Furthermore, with such tools it is difficult to accurately position the drill and to hold it perpendicular to the floor surface.

Accordingly, it is the principal object of the present invention to provide a portable mounting arrangement capable of securely holding a cutting tool or the like during operation.

It is the further object of the invention to increase the safety of the operator of such a tool.

It is the still further object of the invention to improve the speed and accuracy with which the tool may be positioned and operated.

In a principal aspect, the present invention takes the form of a portable tool mount which utilizes both the weight of the tool supporting frame and the weight of the human operator of the tool in order to provide an excellent frictional grip between the tool mount and the load bearing surface upon which it rests. Advantageously, my invention enables a cutting tool to be operated more rapidly, more accurately, and with greater safety to its human operator.

These and other objects, features and advantages of the present invention will become more apparent through a consideration of the following detailed description. In the course of this description, reference will frequently be made to the attached drawings in which:

FIG. 1 is a perspective view of a tool mount embodying the principles of the invention shown with the tool removed and with the operator support platform hinged upwardly such that the mount rests on its four wheels;

FIG. 2 of the drawings shows a perspective view of the portable mount in operating position with the tool in place;

FIG. 3 is a side elevational view of the tool mount in its operating position;

FIG. 4 is a top view of the portable tool mount; and

FIG. 5 is an end elevational view of the portable tool mount.

The perspective view of FIG. 1 shows a wheeled chest 11 with an operator support structure 13 hinge mounted on the chest 11 and positioned upwardly such that the combined weight of the chest 11 and the support structure 13 rests upon four wheels, three of which are visible at 14, 15 and 16 in FIG. 1. The chest 11, which includes three drawers 17, 18 and 19, is provided with a handle 20 (best seen in FIG. 4) which may be used to push or pull the portable tool mount from place to place. The top surface 22 of the chest 11 is surrounded on three sides by an upwardly extending flange 24. As best shown in FIG. 2, four openings 25 through 28 are provided in flange 24 to permit the attachment of a bridle (not shown) which may be employed to lift the entire mounting arrangement with a crane or the like.

The open end of the chest 11 is bounded on its two vertical sides by the vertically oriented sections 30 and 31 of a rectangular tubing member shown generally at 33. Tubing member 33 is shaped in the form of an inverted U. A pair of outwardly extending hinge support brackets 34 and 35 are welded to the vertical tubing sections 30 and 31, respectively. The operator support structure 13, which is hinge mounted to the brackets 34 and 35, comprises a pair of tubing sections shown generally at 40 and 41, each of which is formed from a single piece of tubing and includes four approximately right-angle bends. One end of the bent tubing section 40 is attached to the hinge bracket 34 while the similar end of the tubing section 41 is attached to the hinge support bracket 35. The bent tubing sections 40 and 41 are joined together by three transverse braces 43, 44 and 45, as well as by a transverse rod 49. The braces 44 and 45 are positioned flush against a seat 50 as shown in FIG. 1. A circular shield 52 is affixed to an arm 53 which is pivotally mounted on the rod 49.

As shown in FIG. 2 of the drawings, the operator support structure 13 may be pivoted downward about the hinge support brackets 34 and 35 into an operating position where the wheels 14 and 15 are raised off the ground. In this position, a substantial portion of the weight of the chest 11 as well as the weight of the human tool operator (shown in phantom) are supported by a pair of feet 61 and 62. The under surface of feet 61 and 62 may be covered with rubber pads shown at 64 and 65, respectively, in FIG. 1 to provide an improved frictional grip on the load bearing surface upon which the tool mount rests. A pair of angle braces 66 and 67 are welded in place across corner bends in tubing elements 40 and 41, respectively, in order to strengthen the support structure 13 in the region adjacent to the feet 61 and 62.

As shown in the perspective view of FIG. 2 of the drawings, a drilling tool 70 capable of transmitting vibration and torque to a core bit 72 may be mounted on the chest 11 by means of a mounting arrangement including a carriage 75. The carriage 75 is carried on a pair of vertical guide standards 77 and 79. An operating wheel 80 is mounted on a shaft housing 82 (shown most clearly in FIG. 4) which is rigidly affixed to the standard 79. Rotation of the handwheel 80 rotates a gear 84 (seen in FIG. 4) which is enmeshed with a gear track 85 on carriage 75 as shown in FIG. 2. Accordingly, by rotating the handwheel 80, the tool 70 may be moved downward such that its associated core bit 72 passes through the circular shield 52 to engage with and cut through the surface upon which the portable tool mount rests. In moving downward, the carriage 75 carries with it an arm member 89 to compress a coil spring 90 which surrounds guide standard 77 as shown most clearly in FIG. 5 of the drawings. The compression spring 90 compensates for the weight of the tool 70 to facilitate retraction of the core bit 72 from the drilled hole.

The novel portable tool mount contemplated by the invention allows the weights of the mounting frame and the operator to be combined such that a secure frictional grip between the load bearing surface and the tool bearing surface and the tool is obtained. An extremely secure grip is obtained even though the frame itself is relatively light. The drilling operation is accomplished more rapidly, more accurately, and with greater safety to the operator since the tool is more easily controlled.

The embodiment of the invention which has been described is merely illustrative of one application of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims

I claim:

1. A tool mounting arrangement adapted to firmly grip a load bearing surface comprising:

a tool for working said surface;

a frame for mounting said tool;

a set of wheels;

a foot mounted for movement on said frame such that said foot rests on said load bearing surface when said foot is in a lowered position and wherein said frame rests entirely on said set of wheels when said foot is in a retracted position;

a platform for carrying at least a portion of the weight of the human operator of said tool; and

said platform being mounted on said frame such that the operator's weight applied to said platform combines with at least a portion of the weight of said frame to increase the frictional force with which said foot grips said surface.

2. A portable tool mounting as set forth in claim 1 wherein said platform is mounted on said frame at a horizontally extended distance in a first direction from said foot and wherein the center of gravity of said frame is located at a horizontally extended distance in the opposite direction from said foot such that the weight of said frame is capable of counterbalancing the operator's weight applied to said platform.

3. Apparatus for working a load bearing surface which comprises, in combination,

a cutting tool,

a frame for mounting said tool,

a plurality of wheels for carrying said frame on a surface,

a platform structure for bearing the weight of the human operator of said tool,

said platform structure being hinge mounted on said frame for movement between an operating position and a retracted position,

at least one load bearing friction pad affixed to said platform structure and positioned such that when said structure is in said operating position said pad is positioned below the horizontal position of at least one of said wheels so to raise said one wheel off of said surface, and such that a substantial portion of the combined weight of said frame, said structure and said operator is borne by said pad, and,

when said structure is in said retracted position, said pad is positioned above the horizontal position of all of said wheels such that the entire weight of said frame and said platform is carried by said wheels.

4. Apparatus as set forth in claim 3 wherein said tool is a drill and wherein said frame includes a movable carriage for mounting said drill.

5. Apparatus as set forth in claim 3 wherein said platform is mounted on said frame at a horizontally extended distance in a first direction from said pad and wherein the center of gravity of said frame is located at a horizontally extended distance in a direction from said pad which is substantially opposite to said first direction such that the weight of said frame is capable of counterbalancing the weight of said human operator about the pivot formed by said pad.