GB2287320A - Hand held caliper measuring device - Google Patents

Abstract

Hand held calliper measuring device (2) includes a first arm (4) and a second arm (10) pivotably connected by hinge (16). A pointer (8) of the first arm (4) projects across a handle portion of the second arm (10) and cooperates with an arcuate scale (32) near a distal end of the handle portion. A large aperture (30) in the handle portion permits easy single handed operation of the device by facilitating access to the pointer (8). Concave regions (26 and 28) adjacent object gripping regions of the arms permit the device to reach round an object to measure another object. A flat region of one gripping region of one arm facilitates measurement perpendicular to a flat surface of an object to be measured. <IMAGE>

Description

LINEAR MEASURING DEVICE The present invention relates to a hand held device with a scissor like action for measuring a linear dimension of an object.

Such hand held devices for measuring the thickness or some other linear dimension of an object have been proposed in the past. An example of such a device is described in GB patent 2070252 which includes two arms which are hingeably interconnected. Object contacting portions of the arms rotate towards and away from each other as the arms are rotated relative to each other. In order to obviate the necessity of using two hands to operate the device when there is a requirement to separate the handle portions of the arms a spring member is provided between the handle portions for this purpose. The provision of the spring adds undesirably to the cost and complexity of the device.Furthermore the fact that the overall size of the handle portion of the device changes depending on the size of the object being measured tends to make the device difficult to use under certain circumstances and means that the setting of the device can be altered easily as a result of the handle portion being knocked.

Similar devices with like drawbacks are described in GB patents 705872 and 602701.

The object of the invention is to provide a hand held measuring device for measuring a linear dimension of an object which overcomes at least some of the aforementioned disadvantages of prior art measuring devices such as those discussed above.

A particular object of the invention is to provide such a measuring device which can be easily operated with one hand and yet does not need to employ a spring or other return means for moving parts of the device in an opening or closing direction.

Thus according to the invention there is provided a hand held device for measuring a linear dimension of an object the device comprising first and second arms interconnected by a hinge operatively located between first portions of both arms which are for contacting the object and second portions of both arms which constitute a handle part of the device, the second portion of one arm being provided with a scale relative to which the second portion of the other arm is movable wherein within the operating range of the device defined by the scale an area swept by the second portion of the first arm lies substantially within an area bounded by the perimeter of the second portion of the second arm.

The handle of such a device will essentially be formed by the second portion of the second arm which will be securely held in the palm of a user's hand. The second portion of the first arm can then be moved by a finger or thumb of the same hand in either direction so as to adjust the distance between the object contacting first portions of the arms. The device can be used in either of the user's hands by positioning the second portion of the second arm closest to the user's palm so that the second portion of the first arm is positioned outermost for finger or thumb manipulation.

So as to enable even greater flexibility of the way in which the device can be used the second portion of the second arm preferably includes an aperture through which manual rotation of the first arm relative to the second arm can be effected.

The scale is preferably provided adjacent a distal end of said one arm so as to increase the accuracy of the device. The further from the hinge the scale is located the greater the travel of the second portion of the first arm will be with respect to the scale.

As the second handle portion of the second arm will have a significant extent across which the first arm travels the scale is preferably provided on the second portion of the second arm. With such an arrangement the scale can be arranged so as not to project beyond the second handle portion of the second arm.

In order to facilitate measuring a linear dimension of an object perpendicularly to a flat surface of the object preferably the object contacting first portion of one arm includes a flat surface. This flat surface preferably extends over a distance of at least 30mm and more preferably 50mm generally towards and away from the axis of the hinge.

The first arm portions between the hinge and an object contacting regions preferably include confronting concave regions configured so as to be able to accommodate an obstruction which projects at least 80mm and more preferably 100mm on both sides of an object being measured.

So as to make production of the device as simple and as cheap as possible each arm is preferably essentially constituted by a flat plate like member.

The invention will now be described by way of example only with reference to the accompanying figures in which: Figure 1 shows a side view of the device in the closed position; and Figure 2 shows a side view of the device in the open position.

The device 2 includes a first arm 4 with an object contacting portion 6 and a handle portion in the form of a pointer 8. The device also includes a second arm 10 or member with an object contacting portion 12 and a handle portion 14. The arms 4 and 10 are both flat plate like members made of metal, plastics or any other suitable material.

The two arms 4 and 10 are connected near their central regions by means of a hinge 16 which may be constituted by a bolt and nut, rivet or any other suitable means. One of the arms may be formed with an integral lug which is engageable, eg by snap engagement, with the other arm.

The object contacting portion 6 of the first arm has a radius of curvature about an axis 20 (which is parallel to the hinge axis 17) of 6mm. This radius of curvature should be less than 10mm so as to reduce inaccuracy caused by relatively angular movement of the object contacting portions as the device is opened. The object contacting portion 12 of the second arm 10 has a flat surface 22 which extends for a distance A of 50mm in a direction perpendicular to the direction of the shortest line joining the object contacting portions 6 and 12 of the two arms.

This arrangement will ensure that when the flat object contacting portion 12 is held flush against one surface of an object, the dimension measured by the device will be that perpendicular to that surface. In this manner inaccuracies introduced by measurements taken which are skewed relative to the perpendicular to the surface of the object can be largely avoided. The flat surface may also extend a significant distance in a direction perpendicular to the projection shown in the figures, ie towards and away from the viewer. This will still further alleviate the problem of skewed dimensions being measured.

The object contacting portions 6 and 12 of each arm are connected to the handle portions 8 and 14 by concave regions 26 and 28 respectively, which are configured to allow the device to reach round an object (eg a window frame) which extends a distance C of 100mm on either side of the opposing surfaces of an object being measured.

The handle portion 14 of the second arm has an aperture 30 which permits finger or thumb access to the pointer 8 from either side of the device over the whole of the operating range of the device defined by an arcuate scale 32 provided adjacent the distal end of the second arm 10 remote from the object contacting portion 12. The scale 32 may be embossed on the material constituting the arm 10 or may be applied as a transfer or painted on.

As the object contacting portions 6 and 12 of the arms are moved relative to each other the pointer 8 moves relative to the scale 32 thus indicating the distance between the object contacting portions. In Figure 2 the device is shown measuring an object 36, shown in dotted lines, which has a thickness of 50mm. Throughout the entire operating range of the device defined by the scale 32 the pointer 8 remains within the area bounded by the perimeter 34 of the handle portion 14 of the second arm 10.

The device can be made in a wide variety of sizes very easily and cheaply and is capable of measuring to an accuracy of approximately 0.5mm. The device is accordingly highly suitable for use in the home, garage, school etc.

ruler 38, series of labelled apertures of different sizes (not shown) or other measuring means may also be easily incorporated into the device.

The measuring device according to the invention can easily be manipulated by one hand to measure the thickness of an object, possibly located on the far side of an obstruction.

Claims (13)

1. Hand held device for measuring a linear dimension of an object the device comprising first and second arms interconnected by a hinge operatively located between first portions of both arms which are for contacting the said object and second portions of both arms which constitute a handle part of the device, the second portion of one arm being provided with a scale relative to which the second portion of the other arm is movable wherein within the operating range of the device defined by the scale an area swept by the second portion of the first arm lies substantially within an area bounded by the perimeter of the second portion of the second arm.

2. Device as claimed in claim 1 wherein the second portion of the second arm includes an aperture through which manual rotation of the first arm relative to the second arm can be effected.

3. Device as claimed in claim 1 or 2 wherein the scale is provided adjacent a distal end of said one arm.

4. Device as claimed in claim 3 wherein a distal region of said other arm co-operates with the scale.

5. Device as claimed in any preceding claim wherein the scale is provided on the second portion of the second arm.

6. Device as claimed in any preceding claim wherein the first arm portions have confronting concave regions configured so as to be able to reach round an obstruction.

7. Device as claimed in claim 6 wherein the concave regions are configured so as to reach round an obstruction projecting 80mm on both sides of an object being measured.

8. A device as claimed in any preceding claim wherein the object contacting first portion of one arm includes a flat surface.

9. A device as claimed in claim 8 wherein the flat portion is substantially parallel to the rotational axis of the hinge.

10. Device as claimed in claim 8 or 9 wherein the flat surface extends a distance of at least 30mm in a direction substantially perpendicular to the shortest line joining the first and second contacting portions.

11. Device as claimed in any preceding claim wherein each arm is essentially constituted by a plate like member.

12. Device claimed in claim 11 wherein each plate like member constituting an arm is substantially flat.

13. A device substantially as herein described with reference to the accompanying figures.