WO1995004915A1

WO1995004915A1 - Extendible measuring bar

Info

Publication number: WO1995004915A1
Application number: PCT/AU1994/000448
Authority: WO
Inventors: Allan Reid Taylor
Original assignee: Allan Reid Taylor
Priority date: 1993-08-06
Filing date: 1994-08-05
Publication date: 1995-02-16

Abstract

There is a measuring bar for determining internal dimensions within a confined space such as a window or door frame, etc. The measuring bar comprises a sleeve (1) and at least one graduated rod (6) longitudinally slidable within said sleeve section between a withdrawn position in which the rod is substantially within said sleeve (1) and an extended position in which a substantial portion of said rod protrudes from one end of said sleeve. In use the bar is located within said confined space, the rod (6) extended between chosen points within said space and the distance therebetween read off graduated scale (9). For larger dimensions which cannot be bridged by extending rod (6) alone, a second rod (5) is first extended out from the opposite end of the sleeve (1) to its full length before rod (6) is used to bridge the remaining distance and obtain the reading off graduated scale (9).

Description

EXTENDIBLE MEASURING BAR

This invention relates to measuring instruments and more particularly although not exclusively to an extendible bar for determining the internal dimensions of confined spaces such as window or door frames or the like.

Existing measuring devices as commonly used by tradesmen or handymen typically comprise a spring loaded roll of steel or plastic tape which has a coupling flange at the free end. In use the free end of the tape may be hooked at one point on a structure or frame etc. and the tape unrolled to the second point where a reading is taken.

Another known device comprises a set of hinged rulers which fold out from a collapsed configuration to form a graduated metre stick or the like. Such existing apparatus however are awkward to use when surveying internal or confined areas such as door or window frames where there may be no niches available to anchor the end of a tape and little space in which to manoeuvre the hinged sections of a conventional measuring stck.

It is therefore an object of this invention to ameliorate the aforementioned disadvantages and accordingly an extendible measuring bar is disclosed which may be used for determining internal dimensions of a confined space such as a window or door frame or the like, said measuring bar comprising a sleeve section, at least one graduated rod longitudinally slidable within said sleeve section between a withdrawn position in which said rod is substantially within said sleeve and an extended position in which a substantial portion of said rod protrudes from an end of said sleeve whereby in use said bar may be located within said confined space, the rod extended between chosen points of said space and the distance therebetween read off said graduated rod.

Preferably there are two rods slidable into opposite ends of said sleeve.

It is also preferred that the sleeve include a clamp means for releasably locking one of said rods at or between said withdrawn and extended positions.

The currently preferred form of this invention will now be described with reference to the attached illustrations in which:

Figure 1 is a side view of a measuring bar according to this concept,

Figure 2 is a plan view of the bar of figure 1,

Figure 3 is a cross-sectional view of the bar of figure 1 along the lines A-A,

Figures 4 and 5 are detailed side and end views respectively of the bar showing one form of clamping mechanism, and

Figure 6 shows a second form of clamping mechanism for the bar. Referring first to figures 1 to 3 the bar may comprise a sleeve 1 of extruded aluminium. The sleeve may be of some nominal length of say 1.4 metres and be rectangular in cross-section. The interior may be divided as shown into upper and lower slide tracks 2 and 3 by inwardly directed flanges 4. Slidably mounted within these tracks are a pair of rods 5 and 6. These rods may also be of extruded aluminium and with this embodiment are generally square in cross-section with rail means 7 protruding from each corner. These rails abut the inside corners and flanges 4 of the sleeve and provide a bearing surface on which the rods slide smoothly into and out of the sleeve. As best shown in figure 1 the rods preferably slide out of opposite ends of the sleeve and thus they may be extended to bridge a space much larger than the length of the sleeve alone. The ends of the rods may also be fitted with rubber or plastic caps 8.

In use for example when measuring the inside dimensions of a garage door frame the sleeve 1 with both rods initially withdrawn inside is aligned along the dimension to be measured eg. height or width. If the dimension can be bridged by extension of rod 6 alone then this is slid outwardly until contact is made with the inside surface of the frame and the measurement is read off the graduated scale 9 on the upper face at the point 9A of exit from the sleeve. For larger dimensions rod 5 is first extended to its full length before rod 6 is used to bridge the remaining distance and to obtain the reading. Preferably as mentioned earlier the length of the sleeve and also the rods would be multiples of some basic unit such as a metre or yard etc.

Although not shown in the drawings, as a further preferred feature, a second set of grooved rods may be fitted within the ends of rods 5 and 6. This second set may be drawn out by the user to provide additional optional extension of up to say 6 metres.

As shown in figures 4 and 5 a clamp mechanism may be provided for one of the rods. This may comprise a bolt 10 which extends transversely through the sleeve between the two rods 5 and 6 and adjacent one end. The bolt shank is fitted with a knurled knob 11 or the like which allows the bolt to be hand tightened. There is also a slot or channel 12 cut inwardly from this end in each side of the sleeve. This insures that only the upper track 2 of the sleeve as shown in figure 3 is compressed inwardly as the knob 11 is tightened and thus only the corresponding rod 5 is locked. When used to measure particularly wide spaces which cannot be bridged by extending rod 6 alone rod 5 is first extended to full length and locked before the second rod 6 is withdrawn as necessary to complete the distance so that a reading can be made off scale 9.

As an alternative to the above clamping mechanism a drop link 13 (see figure 6) may be fitted through a set of elongated apertures 14 extending through the sleeve 1 and aligned at right angles to it. The link is so positioned that when rod 5 is extended to its full length the link drops from the position shown down behind the inside end 15 of the rod to secure it against accidental movement back into the sleeve. To release the rod 5 the sleeve may be turned over so that the link through its own weight falls out of engagement.

It will thus be appreciated that this invention at least in the form of the embodiments described provides a novel and useful measuring tool for confined spaces. Clearly however the example disclosed is only the currently preferred form of this invention and a wide variety of modifications may be made which would be apparent to a person skilled in the art. For example the invention is not limited to any particular length or cross-sectional configuration for the sleeve and rods. Also, while it is currently preferred to manufacture the device from extruded aluminium other metals or even a suitably strong plastic may be used.

Claims

The claims defining the invention are as follows:

1. A measuring bar for determining internal dimensions within a confined space such as a window or door frame or the like, said measuring bar comprising a sleeve section, at least one graduated rod longitudinally slidable within said sleeve section between a withdrawn position in which said rod is substantially within said sleeve and an extended position in which a substantial portion of said rod protrudes from an end of said sleeve whereby in use said bar may be located within said confined space, the rod extended between chosen points within said space and the distance therebetween read off said graduated rod.

2. The measuring bar as claimed in claim 1 wherein there are two rods longitudinally slidable within respective opposite ends of said sleeve section.

3. The measuring bar as claimed in claim 1 wherein one of said two rods is non-graduated.

4. The measuring bar as claimed in claim 3 wherein the non-graduated rod is releasably lockable at or between said withdrawn and extended positions.

5. The measuring bar as claimed in claim 4 wherein said sleeve is rectangular in cross-section, and the interior is divided into adjacent parallel slide tracks for said rods by inwardly directed flanges.

6. The measuring bar as claimed in claim 5 wherein said at least one rod is formed from extruded aluminium and is generally square in cross- section with rail means protruding from each corner, said rail means comprising a bearing surface by which said at least one rod slides in said sleeve.

7. The measuring bar as claimed in claim 6 wherein said clamp means comprises a drop link which is fitted through an elongated aperture extending through the sleeve and aligned at substantially right angles thereto, said link being positioned so that when said non-graduated rod is extended the link drops down behind the ^"inside end of said non-graduated rod and locks it in place.

8. The measuring bar as claimed in claim 7 wherein a second pair of grooved rods are fitted within respective ends of said two rods, said grooved rods being extendible out by a user to provide additional optional extension of the measuring bar.

9. A method of using the measuring bar as claimed in claim 1 to determine internal dimensions within a confined space, said method comprising the steps of:

- locating said measuring bar within said confined- space, and - extending said graduated rod as necessary to enable said measuring bar to bridge the distance between two chosen points within said space, and

- reading the distance between said points off said graduated rod.