GB2201911A - A bending machine with angle indication - Google Patents

Abstract

A machine 130 for bending conduits etc has angle-indicating device 140 mounted on its handle 132, 133, the device comprising a chamber with transparent walls and partly filled with a fluent material such as coloured water, and having angle-indicating indicia (16, Figs 2-8 not shown) which can be rotated relative to the handle. In a preferred arrangement the curved circumferential wall of the chamber is transparent and carries the indicia (16). <IMAGE>

Description

A bending machine with angle indication The present invention relates to a bending machine for bending an object through a desired angle and more particularly to a machine for bending pipes, tubes or conduit etc, especially in a vertical plane.

U.S. 4425784 discloses a bending machine in which an angle indicator in the form of a spirit level is attached to a handle thereof. The spirit level has angle indicating marking and indicates 450 when the air bubble is adjacent to the mid-point of the indicator. However, when starting a bending operation in practice, the bubble is rarely at the mid-point, so a complicated angle-subtraction operation needs to be performed by the operator. If this is done incorrectly, or the operator resorts to guesswork, a conduit etc with an inaccurate bend results. When the angle is checked against square shapes, the conduit usually needs to be inserted, bent, taken out and rechecked; this is arduous, time-consuming and often results in an end product of poor quality.

The present invention seeks to overcome or at least reduce the above problem.

According to the present invention there is provided a machine for bending an object comprising an operating member in which pivoting of the operating member causes the object to be bent through a desired angle, wherein mounted in or on the operating member is an angle-indicating device comprising a circular chamber having at least one transparent wall, the chamber being partially filled with a fluent material and having a central axis parallel to the pivotal axis of the operating member, and the device incorporating circumferentially-spaced angle-indicating indicia relative to which the surface of the fluent material can be viewed, at least the part carrying the indicia being rotatably mounted relative to the operating member about the central axis of the chamber.

Although GB 2149108 discloses a goniometer in which a calibrated circular dial is rotatably mounted on a backing member, this is disclosed as being used solely for medical purposes. There is no suggestion that the goniometer can be used for any other purpose, especially not conduit-bending or the like. The present invention lies in applying an angle-indicating device with adjustable indicia to satisfy the above need in the conduit-bending filed, i.e. to overcome the problems of inaccuracy and poor quality mentioned above.

The invention is based on the fact that the free surface of any volume of a fluent material (especially a liquid) will be horizontal.

Preferably the volume of the fluent material relative to the volume of the chamber is such that its surface or each of its surfaces lies on a diameter of the circular chamber.

A further disadvantage of the machine of U.S. 4425784 is that during bending, the angle markings cannot be easily viewed by the operator.

In a preferred embodiment of the present invention the indicia are provided on a transparent curved circumferential wall of the chamber. This has the additional advantage that the operator of the bending machine who stands above the operating member can easily look down on the angleindicating device and monitor from above the angle through which the conduit etc has been bent.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig.l shows a conduit-bending machine in accordance with the present invention; Figs 2a to 7a and 2b to 7b show front and sectional side views of respective angle-indicating devices which can be used in the machine of Fig.l; Fig.8 shows a top view of an angle-indicating device in another embodiment of the present invention: and Fig.9 shows a perspective view of a spherical angleindicating device.

Fig.l shows a machine 130 for bending pipes or electrical conduits etc 131. The machine comprises a handle 132 the amount of rotation of which determines the angle by which the conduit 131 is bent. Handle 132 is located in a cylindrical sleeve 133 which already has a plurality of holes 134, e.g. to cater for different sizes of conduit to be bent. Mounted in one of the holes 134 is an angleindicating device 140 in accordance with the present invention, and in particular any of the devices 78,80,90,100,110,120,150 shown in the other Figures.

Figs 2 to 4 show detailed views of devices 70,80,90. Device 70 is constructed as a relatively short hollow cylinder with a fitting 71 which snap fits into a surrounding body or other suitable mount or support. The cylinder defines watertight chamber and at least the front wall 72 is transparent being of glass or clear plastics material. The chamber is half-filled with a liquid 18 such as coloured water. Device 80 is also relatively short, but has an exterior screw thread 81 for mating with a corresponding female thread on a surrounding body etc. Device 90 comprises a relatively long cylindrical chamber which snap-fits or plugs into a surrounding body etc. The front end walls 72,82,92 of the devices carry a seal or indicia 16 and are fixed to the other walls forming the chamber. The indicia indicate, for example, Oo to 3600.In order that devices 70,80,90 can be used as angle-indicating devices, either the entire devices are rotatably mounted about their central axis in the respective surrounding body, or they are fixed to the respective surrounding body and the latter rotates in a mounting in the operating member, i.e handle sleeve 133.

Figs 5a and 5b show an angle-indicating device 100 comprising a short cylindrical chamber half-filled with a liquid 18. The front wall carries angle-indicating indicia 16 and integrally attached to the centre of the rear wall is a threaded or push on member 104. The cylindrical side wall of the chamber is notched or knurled to enable it to be manually gripped. The member 104 permits the device 100 to be rotatably mounted in a support member, i.e. handle sleeve 133. To measure the amount of rotation of the support member in the vertical plane of the device 100 between first orientation and a second orientation, the device 100 is manually rotated (with the support member in its first orientation) until the liquid level is coincident with a convenient datum indicium on the front wall.The support memer is then rotated and the angle moved is readily read off from the front wall by noting the new indicium with which the liquid level is coincident.

Figs 6a and 6b show an angle-indicating device 110 in which the angle-indicating indicia 16 are on a ring 111 rotatably mounted on the cylindrical chamber (by a screw-thread or otherwise). In this case, the member 104, which is separated from the rear wall of the chamber by a spacer element 114, does not need to be freely mounted in its support member since the initial datum alignment can be achieved simply by rotating ring 111.

Figs 7a and 7b show an angle-indicating device 120 in which the liquid 18 half fills a toroidal chamber 121 which is mounted on member 104 by means of a back plate 122 which also carries the indicia 16. The device 120 is manually rotatable relative to its support member for initial indicium setting by means of a knob 124. As shown in Fig 7a, liquid 18 can contain solid spherical members which roll around within chamber 122.

In preferred arrangements, the curved circumferential walls of the above embodiments are also transparent to enable the angle to be read from above. In addition these walls preferably carry the indicia to further facilitate reading of the angle.

Referring now to Fig.8, an angle-indicating device 150 comprises a cylindrical chamber in which the curved circumferential wall is transparent and carries the indicia 16. The device is shown rotatably mounted on a handle 233 having a rectangular cross-section. Angle-indicating indicia 16 can additionally or alternatively be provided along the right hand edge and or a central region of the chamber. The device 150 of Fig.8 may be used independently of conduit-bending machines e.g. as a level device. By using as device 140 a device 70,80,90,100,110,120 or 150, the problems of unsatisfactory bending of a conduit are avoided.

With handle 132 in its initial position I, the device 140 is quickly zeroed, i.e. the device or its angular dial, is rotated so that the liquid level corresponds to 00. The handle is then rotated to position II (450) or position III (900) or any other desired position and the required bending is usually achieved first time. Even if this is not achieved, the amount of error can readily be determined and immediately remedied. The device 140 can be quickly zeroed even if the handle 132 is not initially vertical. The device 140 is conveniently located in a hole already provided in the machine 130 so that no modification thereof is required.

The positions at 900 1800 and 2700 on the angle-indicating scale are preferably emphasised since these are then most common angles through which conduits are required to be bent. Similarly the intermediate 450 positions may also be emphasised, possibly to a lesser extent.

Numerous modifications may be made to the above-described devices. If only a restricted angular range is to be covered the chamber may be defined by only part of a circle.

The chamber may be cylindrical, toroidal or spherical and parts of it may be opaque. A spherical level and angleindicating device 125 is shown in Fig.9. It is particularly advantageous when it is not practical to keep the device in a vertical plane, e.g. on an uneven surface, and may also be used independently of conduit-bending machines, e.g. as a level device.

Although the liquid surface preferably corresponds to a diameter of the circle (for optimum ease of reading) this is not essential and it may correspond to a chord of the circle (with the liquid filling more than or less than half the volume of the chamber); in such a case the indicia are modified to relate to the chord or set of chords which correspond to the positions of the liquid surface.

The liquid may be water or any other liquid (preferably coloured). Mercury can also be used. The liquid may be supplemented or replaced by a fluent solid e.g. a powder or other particulate matter. The particles are preferably spherical, but may have any shape provided they are sufficiently small and smooth. Ball-bearings may be used.

The upper part of the chamber may be occupied by air, or another gas, or may be under vacuum; another possibility is for dense particles to be provided in a chamber topped-up with a less dense liquid; yet a further possibility is for the chamber to contain two immiscible liquids of different densities.

Claims (9)

1. A machine for bending an object comprising an operating member in which pivoting of the operating member causes the object to be bent through a desired angle, wherein mounted in or on the operating member is an angle-indicating device comprising a circular chamber having at least one transparent wall, the chamber being partially filled with a fluent material and having a central axis parallel to the pivotal axis of the operating member, and the device incorporating circumferentially-spaced angle-indicating indicia relative to which the surface of the fluent material can be viewed, at least the part carrying the indicia being rotatably mounted relative to the operating member about the central axis of the chamber.

2. A machine according to claim 1, wherein the indicia are on a or the transparent wall.

3. A machine according to claim 1, wherein the indicia are on a member fixed relative to the chamber.

4. A machine according to any preceding claim wherein said transparent wall is the curved circumferential wall of the chamber.

5. A machine according to any of claims 1 to 3 wherein said transparent wall is the front wall of the chamber and the volume of the chamber is such that its surface or each of its surfaces lies on a diameter of the circular chamber.

6. A machine according to any preceding claim wherein the device is attached to the operating member magnetically.

7. A machine according to any preceding claim wherein the chamber is cylindrical.

8. A machine according to any of claims 1 to 6 wherein the chamber is annular.

9. A machine for bending an object substantially as herein described with reference to Fig.l and any of Figs 2 to 9 of the accompanying drawings.