GB2220078A

GB2220078A - Apparatus for measuring the angle between two adjacent surfaces

Info

Publication number: GB2220078A
Application number: GB8815106A
Authority: GB
Inventors: Peter Roger Pearce-Harvey
Original assignee: PEARCE HARVEY PETER ROGER
Current assignee: PEARCE HARVEY PETER ROGER
Priority date: 1988-06-24
Filing date: 1988-06-24
Publication date: 1989-12-28
Also published as: GB8815106D0

Abstract

The apparatus comprises two arms (12, 14) each arm having at least one substantially straight face, one end of each arm being pivotally connected to the other. A guide rod (28) having a measuring scale is interposed between the two arms and has a slider (38) movable therealong. Two struts (30, 32) one for each arm are pivotally connected at one end to an intermediate position along its respective arm, and at the other end to the slider (38). The slider further includes locking means (40) to lock it onto the rod. <IMAGE>

Description

"APPARATUS FOR MEASURING THE ANGLE BETWEEN TWO ADJACENT SURFACES" The present invention relates to an apparatus for measuring the angle between two adjacent surfaces and in particular the internal or external angle at a corner between two wall surfaces.

Prior art devices have generally consisted of a pair of protractors each having at least one generally straight edge, the two protractors being pivoted to one another.

Such devices suffer from the disadvantage of firstly being bulky due to the presence of the protractor and also of being inaccurate in that the edges could easily be forced to an angle other than the measured angle unless the device is provided with a particularly good locking means.

According to the present invention there is provided an apparatus for measuring the angle between two adjacent surfaces, said apparatus including two arms each having at least one generally straight face and each being pivotally connected to the other at one end thereof at a common pivot at separate spaced pivots on an intermediate member; a guide rod interposed between the two arms and having one end secured or pivotally connected to said pivot or to said intermediate member; two struts, each being pivotally connected at one end to an intermediate position along a respective arm and pivotally connected to a slider at the other end, said slider being slideable along said rod; and locking means releasably to lock said slider onto said guide rod.

Once the two faces have been correctly abutted against the two surfaces whose angle is to be measured, the apparatus is locked and can be removed and maintained at the measured angle either for measurement or for direct transposition of the angle onto a drawing or a working surface of a member to be fitted against the two surfaces.

Furthermore the apparatus of the present invention can be folded into a compact form so that it can be easily carried.

The guide rod can be provided with a calibrating scale so that the angle between the two edges can be directly measured. The apparatus may also be specifically adapted to measure angles greater than 1800 and preferably angles of greater than 2700.

The following description is given merely by way of example with reference to the accompanying drawings in which: Fig. 1 shows schematically the apparatus of the present invention; Fig. 2 shows a cutaway section of the apparatus of Fig. 1 to show the locking means.

Fig. 3 shows details of the slide of Figs. 1 and 2.

Fig. 4 shows details of a section of a second embodiment of the present invention.

Referring to Fig. 1, the apparatus includes two arms 12,14 each having a generally straight face 15,16 and being of generally square U-shaped cross-section. Each arm 12,14 is permanently fixed at one end to a bracket 18,20, the lower end 22,24 of each bracket extending beyond its respective arm 12,14, both longitudinally and laterally of the arm. Each bracket 18,20 is pivotally connected to the other by means of pivot 26 and a straight guide rod 28 is interposed between the arms 12, 14 and is also connected to the pivot 26. Struts 30,32 are each pivotally connected at one end to an intermediate position along the length of each arm 12,14 by pivots 34,36 and at the other end to a slider 38 which is slidable along the guide rod 28. The slider 38 can be releasably fixed to the guide rod 28 by means of a screw threaded knob 40, as best seen in Fig. 2.Any other suitable form of locking means may be used in place of the threaded knob 40.

The slider 38 has a first opening 42 to slidably accommodate the guide rod 28 and a second opening 44 to accommodate the screw threaded rod of the knob 40. The upper portion of the slider 28 is preferably formed by a generally cylindrical portion 46 having a shoulder 48 as best seen in Fig. 3. On assembly of the apparatus, the strut 30 can be placed onto the top surface of the slider 38 and held in place by means of a washer and a removable clip. This arrangement enables the knob 40 to be removed completely from the slider 38 without the strut coming away from the sleeve 38. The lower strut 32 is held in place by means of a screw which engages into a recess at the bottom of the slider 38.

Each arm 12,14 further includes, at its free end, a spacer block 50,52, each block being dimensioned to keep the minimum distance between the free end of each arm 12,14 the same as that between the pivoted ends of the arms when the arm is in the closed position to prevent the wedging together of the various components.

The slider 38 and the struts 30,32 cause the arms 12,14 to tilt about pivot 26 and thus to change the angle between them and especially between the outer faces 15,16.

The brackets 18,20 are preferably dimensioned so as to enable the arms 12,14 to pivot to an angle greater than 1800 and preferably to an angle of greater than 270". The locking of locking means 40 on the slider 38 prevents the further pivoting of the arms 12,14 and the struts 30,32 thus retaining the arms 12,14 at the angle at which they were locked.

In an alternative embodiment of the invention, the lower end of the rod 28 is fixed to an intermediate member 56 provided with spaced pins 57, 58 each of which provides a pivot for a respective arm 12, 14. The struts (not shown in Figure 4) in such a construction would be cranked to allow the arms to take up an angle of 1800 or more.

The rod 28 may be pivotally connected to the member 56.

In use of the device, the locking means 40 is released to enable the slider to slide along the rod 28 to allows the angle between the arms 12,14. The device is placed at a corner between two surfaces, e.g. two walls, whose angle is to be measured. The angle between the two arms 12,14 is altered until the faces 14,16 abut the respective surfaces of the building structure. The locking means 40 is then tightened to lock the arms into position.

The straight rod 28 is preferably provided with a calibrating scale on one side so that the angle can be measured directly. Alternatively the device can be removed from the corner and used directly, for exmple, for the architect's drawings or for the joiner's workpiece to be fitted against the two surfaces.

When not in use, the device can be folded into a closed position, in which there is a small space between the two arms 12,14 to accommodate the straight rod, a part of each strut 30,32 and the slider 38. The locking means 40 is preferably kept in a reachable position so that the sleeve can be locked to the rod 28 and thus the whole apparatus fixed in its closed position.

The apparatus of this invention has the further advantage over prior art devices in that when in its locked position it is compact and does not have a protractor protruding from the main part of the apparatus.

It can also be used to measure the thickness of an article, e.g the diameter of a pipe, by engaging the blocks 50, 52 against opposite sides of the pipe. There may be provided a suitable scale on the guide rod or one can simply lock up the clamp 40 and subsequently measure the spaces between the blocks 50, 52.

Claims

1. An apparatus for measuring the angle between two adjacent surfaces, said apparatus including two arms each having at least one generally straight face and each being pivotally connected to the other at one end thereof at a common pivot at separate spaced pivots on an intermediate member; a guide rod interposed between the two arms and having one end secured or pivotally connected to said pivot or to said intermediate member; two struts, each being pivotally connected at one end to an intermediate position along a respective arm and pivotally connected to a slider at the other end, said slider being slideable along said rod; and locking means releasably to lock said slider onto said guide rod.

2. An apparatus according to claim 1, wherein said guide rod is straight.

3. An apparatus according to claim 1 or 2, wherein said guide rod is provided with a calibrating scale, said scale indicating the angle between the two generally flat faces of the arms.

4. An apparatus according to claim 1, 2, or 3, wherein the pivoted end of said arms is so arranged so as to enable the arms to be rotated to an angle of greater than 1800 .

5. An apparatus according to claim 4, wherein the pivoted end of said arms is so arranged so as to enable the arms to rotate to an angle of at least 270 .

6. An apparatus according to any preceding claim, wherein said locking means includes a screw clamp.

7. An apparatus according to any preceding claim, wherein the free ends of said arms remote from said pivoted ends include spacing blocks for spacing the free ends of said arms at a minimum distance when said arms are closed together.

8. An apparatus for measuring the angle between two adjacent surfaces substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.