US2389314A

US2389314A - Portable tool

Info

Publication number: US2389314A
Application number: US514152A
Authority: US
Inventors: Imhof Alfred Godfrey; Hoyles Louis
Original assignee: IMHOF
Current assignee: IMHOF
Priority date: 1943-01-27
Filing date: 1943-12-13
Publication date: 1945-11-20
Anticipated expiration: 1962-11-20
Also published as: GB557254A

Description

Nov. 20, 1945. A. G. IMHOF EI'AL PORTABLE TOOL Filed Deb. 15, 1945 2 Sheets-Sheet 1 No v. 20, 1945. A. s: IMHOF ET AL 21,389,314

PORTABLE TOOL Filed-Dec. 13, 194s- ZSheets-Shet 2 Patented Nov. 20, 1945 PORTABLE TOOL Alfred Godfrey Imhof, London, and Louis Hoyles, Stanmore, England; said Hoyles assignor to said Imhof Application December 13, 1943, Serial No. 514,152

' In Great Britain January 27, 1943 8 Claims.

This invention relates to means for facilitating the correct positioning and holding of a portable tool such as an electrically driven drilling machine, commonly known as an electrically driven drill, or an electric drill.

According to the present invention we provide a portable tool such as an electrically driven drilling machine with a guide plate which is adapted to be pressed against the action of a spring or its equivalent on to the work to be operated on and is connected to the casing .or body in which the tool holder is mounted by means of one or more guides of improved construction which constrain the plate to move (relatively to themachine) in a direction parallel'with the axis of the tool itself.

At least one of the guides is so arranged that the travel thereof combined with adequate hearing surfaces to maintain the parts in line is greater than in the case of a simple telescopic arrangement consisting of two parts which are pressed towards their extended position by a spring. This increase in travel is efiected by means of a guide (preferably telescopic) comprising two members provided with a third member which serves to maintain the two members aligned, and is constrained to move relatively to the two members as the guide is extended or retracted.

In the accompanying drawings which illustrate theinvention:

Figure 1 is an elevation partly in section and Figure 2 is a sectional plan view;

Figure 3 is a detail view;

Figures 4 and 5 show a modification.

Figure 6 is an elevation partly in section of the arrangement shown in Figure 1 but with parts in a different position.

Referring to Figure 1, l is a portable electrically driven drilling machine shown in dot and peck lines; I" is an ordinary self-centering chuck adapted to hold drills or other tools of different diameters.

l I is a casting which is secured to the casing of the machine l by means of a screw l2 and guide pins l3 which are reduced in diameter at their inner ends and screw threaded. I4 is a casting, the outer end of which forms a guide plate and is provided with tubular extensions I5 forming guides for the pins 13, and with a tubular extension it which forms the outer member or tube of the telescopic guide giving a greater travel than is the case with a simple telescopic guide. I! is the inner member of the telescopic guide and comprises a tube which fits onto a boss IS on the casting l I, and is held thereon by a pin H). as a bearing of considerable length to keep the tubes I 6 and I1 coaxial with one another. The tube I1, is a sliding fit on the sleeve 20 and is provided at its outer end with a peripheral flange 2| which is a sliding fit in the tube Hi. The tube 20 is a floating guide or sleeve which serves I6 is'provided at its outer end with an internally projecting peripheral flange 22 which is a sliding fit on the tube ll. The sleeve 20 is provided with a peripheral flange 23 which is a sliding fit in the tube Hi. 24 is a partition in the sleeve 20. The tube 16 is closed by an end plate 25 which is provided with apertures 26 to allow free ingress and egress of air to and from the tube I6. 21 is a spring located between the boss 18 and

partition

24, and 28 is a spring located between the partition 24 and the end plate 2'5. Normally the tubes t6 and l! of the guide are maintained in their extended position by the

springs

21 and 28, the relative movement between the tubes being limited by the flanges 2| and 22., As the guide is retracted against the action of the

springs

21, 28, the sleeve 20 is also constrained by the

springs

21, 28 to move relatively to the tubes l6 and 11 until finally in the extreme retracted position the tubes l 6 and H and the sleeve 20 take up the position shown in Figure 6.

It will be seen that the distance between the boss 18 and the end plate 25 in the extended position of the guide is reduced by substantially one half when in the retracted position shown in Figure 6 and that at all times the tubes l6 and I! are well supported by the sleeveZil. It will also be seen that with this arrangement if a short drill be employed the telescopic guide would withdraw it an inconveniently long distance from the work. In order to obviate this the outer tube It is provided with a number of screw threaded holes '29 into any one of which a screw 30 can be inserted, as shown in Figure 3, which will be engaged by the flange H on the tube l1 and thereby restrict the outward movement of the guide plate M. In Figure 2 the opening 3| through which the drill I can be seen is provided with three triangular projections 32 which facilitate the placing of the guide plate. 14 in its proper position to drill. Figures 4 and 5 show an alternative arrangement in which the aperture 3! is screw threaded to receive a bush 33 adapted to fit into holes in a .jig, the bush 33 having a central aperture 34 of appropriate diameter to form a guide for the drill to be used.

In operation the tool is placed in position, the guide plate l4 being pressed against the work to be drilled so that its surface is in contact with the surface of the work to be drilled. So long as the guide plate is held in this position, the machine is constrained to move in a direction at right angles to the work.

The guide plate l4 may, if desired, be formed as an electromagnet.

If the work to be drilled is e. g. curved instead of plane the guide plate 14 may obviously be so shaped as to make contact therewith.

Although Figure 1 shows a drilling machine having two telescopic guides (l3, IS) without a guided solely by the telescopic guide, this latter being provided with means such as a key and keyway to prevent rotational movement between the machine i and the guide plate i4.

It has been found that a portable drilling ma chine fitted with a guide plate according to this invention is particularly suitable for drilling several thicknesses of thin material at the same time,

If a jig be used, there-is less wear on the jig (even without the use of a bush such as is showniat 33 Figure 4) the holes made by the drill are circular the risk of breakage of the drill is reduced, and there is less wear on the sides of the drill.

What'we claim is v v 1. In a portable tool, the combination of a tool holder, a guide plate adapted to be pressed against the work to be operated on by said tool, and at least one guide comprising three members slidably mounted relatively to one another, one of the members serving to maintain the other two members in line'with one another, means constraining the said member to move relatively to the two members as the guide is extended or retracted, the said guide connecting said guide plate to said tool, whereby the guide plate is constrained to-move in a direction parallel with the axis of said tool holder, and means tending to force said guide to its extended position;

2. Ina portable tool, the combination of a tool holder, a guide plate' adapted to be pressed against the work to be operated on by said tool, and at least one guide comprising three tubular members slidably mounted relatively to oneanother, one of the members serving to maintain the'other two members coaxialwith one another, means constraining the said member to move relatively to the two members as the guide is extended or retracted, the said guide connecting said guide plate to said tool, whereby the guide plate is constrained to move in a direction parallel with the axis of said tool holder, and means tending; to force said guide to its extended position.

'3. In'a portable tool, the combination of a tool holder, a guide plate adapted to be'pressed against the work to be operated on by said tool, and at least one guide comprising two tubular members slidably mounted on a sleeve, a partition in said sleeve, and means constraining the members and sleeve to move/relatively to one another as the guide is extended or retracted, the said guide connecting said guide plate to said tool, whereby the guide plate is constrained to move in a direction parallel with the axis of said tool holder and means tending to force said guide to its extended position.

4. In a portable tool, the combination of a tool holder, a guide plate having an aperture to enable the end of the tool to be seen where it enters the work and adapted to be pressed against the work to be operated on by said tool, and at least one guide comprising three members slidably mounted relatively to one another, one of the members serving to maintain the other two members in line with one another, means constraining the said member to move relatively to the two members as the guide is extended or retracted,

, to its extended position.

5. In a portable tool, the combination of a, tool holder, a guide plate, a bush on said guide plate adapted to fit into holes in a jig, said guide plate .being adapted to be pressed against the work to be operatedon by said tool and to be positioned by said bush, and at least one guide comprising two tubular members slidably mounted on a sleeve, a

partition in said sleeve, and means constraining the members and sleeve to move relatively to one another as the guide is extended or retracted, the said guide connecting said guide plate to said tool whereby the guide plate is constrained to move in a direction parallel with the axis of said tool holder, means tending to force said guide to its extended position, and means for limiting to various lengths the travel of said guide.

6. In a portable tool, the combination of a tool holder, a guide plate adapted to be pressed against the work to be operated on by said tool, a bush on said guide plate adapted to fit'into holes in a jig, and at least one guide comprising three members slidably mounted relatively to one another, one of the members serving to maintain the other two members in line with oneanother, means constraining the said member to move relatively to the two members as the guide is extended or retracted, the said guide connecting said guide plate to saidtool, whereby the guide plate is constrained to move in a direction parallel with the axis of said tool holder, and means tending to force said guide to its extended position.

'7. In a portable tool, the combination of a tool holder, a guide plate adapted to be pressed against the work to be operated on by said tool,

and at least one guide comprising three members slidably mounted relatively to one another, one

of the members serving to maintain the other two a members in line with one another, means constraining the said member to move relatively to the two members as the guide is extended or retracted, the said guide connecting said guide plate to said 'tool, whereby the guide plate is constrained'to move in a direction parallel with the axis of said tool holder, means tending to force said guide to its extended position, and means for limiting to various lengths the travel of the guide plate relatively to the tool.

8. In a'portable tool, the combination of a tool holder, a guide plate adapted to be pressed against the work to be operated on by said tool, and at least one guide comprisingthree tubular members slidably mounted relatively to one another, one of the members serving to maintain the other two members coaxial with one another,