Cutting by use of rotating axially moving tool – With work-engaging structure other than tool or tool-support – Having tool-opposing – work-engaging surface
Patent
1992-09-11
1994-09-20
Howell, Daniel W.
Cutting by use of rotating axially moving tool
With work-engaging structure other than tool or tool-support
Having tool-opposing, work-engaging surface
408 87, 408111, 408136, 408712, B23B 4514
Patent
active
053484282
DESCRIPTION:
BRIEF SUMMARY
This invention relates to a portable drilling jig and frame for drilling holes in underfloor steel, wood and concrete joists.
When service pipes for gas, electricity, plumbing and central heating have to be installed across wooden joists, it is often common practice to roughly remove a section along the top edge of these joists which drastically weakens them. Furthermore, such pipes can easily be damaged when the floor boards are replaced, or when threshold boards, carpet grippers and carpet tacks are replaced.
When service pipes are installed across rolled steel joists, they are usually laid across the top flange of the joist and the floor boards are cut away to fit around these pipes, which not only weakens the floor boards but leaves the pipes unprotected from flooring nails and carpet grippers and tacks. When electric cables are laid across rolled steel joists they are not protected and can often become chafed and dangerous, and can and do cause fires. Sometimes door thresholds and door frames are cut away as an alternative solution to the problem, but the same disadvantages remain, plus the added weakening of the door frame itself.
The same situation applies when service pipes have to be installed across reinforced concrete joists or lintels.
Thus the present invention provides an underfloor drilling jig and frame comprising a stationary fixed frame with a sliding inner frame, into which is fitted an electric drill and an angled gear-box for coupling to a drill chuck.
We may also claim an underfloor drilling jig and frame comprising a stationary fixed frame with a sliding inner frame configured for receiving an electric drill and an angled gear-box.
In the context of the present invention, the term "angled gear box" means any gearing arrangement which transmits rotational motion through an angle other than 180.degree..
In a particular embodiment, a standard variable-speed electric drill is clamped in a vertical position in a sliding frame, with a standard 90.degree. gear-box, modified to some extent, attached in a horizontal position. A pressure screw is fitted into the modified part of the gear-box, and a long lever applies pressure to the end of this screw, which is positioned along the line of the axis of the gear-box, which results in a quick and easy method of drilling holes in underfloor joists.
A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which:
FIG. 1 shows a side view of the main fixed part of the jig, a sectional view of the rolled steel joist being drilled, a wooden joist, the front section three-stage height control jaws, the height control jacking screws, the lever and sliding lever assembly, the electric drill, (minus cable,) the 90.degree. gear-box and the drill-bit.
FIG. 2 shows a section view along the line A-AA, looking towards the front of the jig, showing the lever support brackets, the bracket connecting bolt and distance collar, the right-angled section support cross-member, a cross-section of the main fixed part of the jig, and the right-angled clamping plate and clamping bolts, all actual size.
FIG. 3 shows a plan view of the electric drill mounted in the sliding frame, the adjustable lever assembly, the height jacking plate, a section of a wooden floor joist, a section of a rolled steel joist, three jacking screw-holes and the main fixed part of the jig with adjustable tension bolts at each end.
FIG. 4 shows the extension rod and lock-nuts for the pressure screw.
FIG. 5 shows a side view of the lever, the pressure screw and lock-nut, the ball-bearing, and metal screw retaining housing.
FIG. 6 shows the threaded connection tube for connecting the pressure screw and the extension rod.
FIG. 7 shows a plan view of the pressure screw, lock-nut, the screw retaining housing, the seelock or pin to retain the nut in the fixed position to enable the pressure screw to be adjusted as required, the ball-bearing and a sectional view of the lever with semi-circular groove, shown actual size.
FIG. 8 shows an end v
REFERENCES:
patent: 628404 (1899-07-01), Forrester
patent: 704657 (1902-07-01), McClellan
patent: 1486933 (1924-03-01), Stoltz et al.
patent: 1517987 (1924-12-01), Henderson
patent: 1750957 (1930-03-01), Fowler
patent: 2291729 (1942-08-01), Koett
patent: 2466965 (1949-04-01), Pitts
patent: 3060769 (1962-10-01), Heider
patent: 4235565 (1980-11-01), Albano
patent: 4669929 (1987-01-01), Olesen
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