GB2477990A

GB2477990A - Laser alignment device and bracket for holding the device

Info

Publication number: GB2477990A
Application number: GB201002977A
Authority: GB
Inventors: Derek White
Original assignee: Cable Management Products Ltd
Current assignee: ABB Cable Management Products Ltd
Priority date: 2010-02-22
Filing date: 2010-02-22
Publication date: 2011-08-24
Anticipated expiration: 2030-02-22
Also published as: GB201002977D0; GB2477990B

Abstract

A battery powered laser alignment device 10 is provided comprising: a tapered body which at one end defines a screw-threaded annulus 15 for attachment to a threaded pipe or pipe fitting 16; a laser emitting apparatus 20; and an internal power switch 26 within said annulus. The threaded pipe or pipe fitting 16 is screwed into the screw-threaded annulus 15 pressing on a circlip 31 or disc 30 thereby urging a housing of the laser 21 inwardly, and consequently causing the power switch 26 of the laser emitting apparatus 20 to be depressed to turn the laser on. The laser alignment device is particularly suited to mitigating the problem with conventional battery powered laser devices wherein the batteries of such devices may go flat as a result of a power switch of the device being accidentally left in an `on' position. The laser alignment device is suited for use in plumbing wherein a laser beam projected from a pipe fitting is utilised to spot the path of a pipe which is to extend from the pipe fitting.

Description

Laser Alignment Device and Bracket This invention relates to a laser alignment device for use in plumbing, and to a bracket for holding said device in use.

It has been proposed to project a laser beam from a pipe fitting in order to spot the path of a pipe which is to extend from the pipe fitting. A laser beam device is in use attached to the pipe fitting, which may for example be a central heating radiator, and projects a beam in the intended pipe direction. The path of the pipe is thus illuminated, and in particular obstructions to the path such as walls and floors, The prior art laser device may consequently be used to mark the location where a through hole is required, thus reducing the risk that such a hole may be positioned inaccurately or be oversize.

Laser devices are typically battery powered, and thus have an on/off switch. If accidentally left in the on' condition, the battery may quickly go flat, and render the device unusable. An external switch may also be knocked on if the device is loose in a toolbox or the like.

According to a first aspect of the invention, there is provided a battery powered laser device having a body defining a screw-threaded annulus for attachment to a threaded pipe or pipe fitting, a laser emitting apparatus, and an internal switch within said annulus and operable through said annulus to turn on said laser emitting apparatus.

Such an arrangement allows the switch to be wholly within the screw-threaded anriulus, and thus substantially protected from being knocked-on accidentally.

In a preferred embodiment the switch is activated directly by the radial end face of the pipe or pipe fitting upon on-screwing of the device. Thus engagement of the pipe or pipe fitting within the screw-threaded annulus results in relative axial movement of said end face with respect to the body of the device, which may be used to activate a momentary on-switch.

In a preferred embodiment the annulus is internally threaded, for example /2" BSP, for engagement with a corresponding external thread of a pipe or pipe fitting.

Preferably the body is circular and symmetrical in section, is closed at one axial end but for an axial aperture for the laser beam, and is open at the opposite end. The opposite end defines the screw-threaded annulus, and is closed internally by a disc which lies on a diameter of the body inboard of the screw thread. Such a disc prevents ingress of debris, as may be found in use in a tool box.

Preferably the disc is urged by a spring axially outwardly of the body against an internal shoulder of the anriulus. The internal shoulder may be constituted by for

example a circlip.

The laser emitting apparatus is preferably a self-contained laser comprising a housing insertable in said body, and incorporating a power source and on switch. In one embodiment the housing is cylindrical and has a radially protruding switch which is activated by inward depression thereof.

In a preferred embodiment, the body of the device is internally narrowed away from screw-threaded annulus so that relative axial movement of said housing results in inward movement of said switch. A return spring is preferably provided between said housing and said one axial end of the body, and in a preferred embodiment is a coil compression spring through which the laser beam passes axially in use.

In a preferred embodiment the housing is located at said one end of the body by a close-fitting internal diameter thereof, and at the other end by a projection on the central axis thereof, which projection closely fits within a hole of a closure disc.

Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only in the accompanying drawings, in which: Fig. I is a side elevation of a laser device according to the invention; Fig. 2 is a schematic longitudinal section through the device of Fig. 1; Fig. 3 illustrates in partial section a male/female adapter for the laser device of Fig. 2; Fig. 4 illustrates in side sectional view a bracket for mounting the laser device of Fig. 2 on a joist; and Fig. 5 is a front elevation of the bracket of Fig. 4.

With reference to the drawings, a cylindrical tubular body (10) of for example aluminium alloy is rotationally symmetrical about an axis (11), and defines an internal recess (12). The recess is substantially closed at one end (13) apart from a small aperture (14) on the axis (11). At the other end (15), the body is open and defines an internally threaded mouth for connection to an externally threaded pipe or pipe fitting (16), typically /2" BSP or 3⁄4" BSP.

Within the recess is located a self-contained laser (20) having a cylindrical housing (21) incorporating the usual circuitry, power source and lens (22). A laser beam (23) projected from the device in use passes through the aperture (14).

The inner end of the housing (21) fits closely within the recess (12) so as to be confined against significant radial movement; axial movement is however permitted against the effect of a coil compression spring (24) which bears on the substantially closed end (13).

At the opposite end the housing (21) has a cylindrical projection (25) on the rotational axis thereof. A momentary on' button (26) of the laser projects radially for sliding contact with an internal tapered face of the recess, which narrows towards the substantially closed end (13). The on' button may be depressed against a return spring (not shown) to activate the laser.

A closure disc (30) has a central aperture which fits closely over the projection (25) against the end face of the housing (21). The outer diameter of the disc is a clearance fit within the threaded end (15), and the disc is retained by a conventional circlip (31) located in a circular recess (32). As illustrated the recess provides an axial clearance for inward movement of the circlip, and hence the disc (30) and housing (21) against the effect of the return spring (24). An elastomeric 0' ring (27) supports and centralizes the housing adjacent the threaded end (15).

In use the pipe or pipe fitting (16) presses on the circlip (31) or disc (30) to urge the housing (21) inwardly, and in consequence to cause the button (26) to be depressed to turn the laser on. In practice two or three relative turns of the body (10) are sufficient.

The body aligns on the pipe or pipe fitting by virtue of the screw threads, and accordingly the laser beam travels on the path of a straight pipe which in use is intended to be connected to the pipe or pipe fitting (16).

On unscrewing the body (10) from the pipe fitting (16), the laser is de-activated as the housing is urged rightwards, so that the risk of inadvertently discharging the power source is minimized.

Fig. 3 illustrates an adapter (35) to allow the body (10) to be screwed to a pipe or pipe fitting threaded to %" BSP. A male /2" BSP thread (36) and a female 3/41 BSP thread (37) are provided. The adapter (35) can be for example moulded of plastics material, and may be used to test the function of the laser guide by inscrewing relative to the body (10).

Figs. 4 and 5 illustrate a joist bracket (50) which may be bent from a steel sheet blank, or moulded from plastics material.

An L' shaped frame comprises downward and transverse planar faces (51, 52) adapted to fit against the top and side of a floor joist (40). A springy rear leg (53) ensures that the frame grips the joist in use. Edges (54, 55) of the faces (51, 52) are turned through 90° to space the planar faces from the joist surfaces as illustrated.

A series of apertures (56) are provided in the front face, and sized to receive the male 1⁄4" BSP thread of the adapter (35), which can be used to secure the laser guide as illustrated, by clamping through the front face (51). The edges (54) provided a clearance to accommodate the adapter (35).

The bracket (50) allows the laser device to be mounted on a joist for spotting the drilling location on the next joist of a series. Once drilled, a third joist may be spotted through the hole in the second joist. This feature allows the difficulty of drilling a series of holes for a straight pipe run to be overcome.

Claims

Claims 1. A battery powered laser device having a body defining a screw-threaded annulus for attachment to a threaded pipe or pipe fitting, a laser emitting apparatus, and an internal switch within said annulus and operable through said annulus to turn on said laser emitting apparatus.
2. A device according to claim 1, wherein said switch is activated directly by the radial end face of the pipe or pipe fitting upon on-screwing of the device.
3. A device according to claim I or claim 2, wherein said body is circular and symmetrical in section, is closed at one axial end but for an axial aperture for a laser beam, and is open at the opposite end.
4. A device according to claim 3, wherein said opposite end defines a screw-threaded annulus, and is closed internally by a disc which lies on a diameter of the body inboard of the screw thread.
5. A device according to claim 4, wherein said disc is urged by a spring axially outwardly of the body against an internal shoulder of the annulus,
6. A device according to claim 5, wherein said internal shoulder is constituted by a circlip.
7. A device according to any preceding claim, and further including a self-contained laser comprising a housing inserted in said body, and incorporating a power source and on switch.
8. A device according to claim 7, wherein said housing is cylindrical and has a radially protruding switch activated by inward depression thereof.
9. A device according to claim 8, wherein said body is internally narrowed away from screw-threaded annulus so that relative axial movement of said housing results in inward movement of said switch.
10. A device according to any of claims 7-9, wherein a return spring is provided between said housing and said one axial end of said body.
11. A device according to claim 10, wherein said spring is a coil compression spring through which the laser beam passes axially in use.
12. A device according to any of claims 7-11, wherein said housing is located at said one end of the body by a close-fitting internal diameter thereof, and at the other end by a projection on the central axis thereof which projection closely fits within a hole of a closure disc.
13. A laser device substantially as described herein with reference to the accompanying drawings.