Alignment tool

An alignment tool 1 for use in marking a surface is disclosed. The tool comprises a handle 6, two pairs of longitudinal arms 2,4 and 3,5 each rotatably mounted in the region of their longitudinal centres to a rotational mechanism provided in or on the handle. The rotational mechanism is arranged such that, in use, movement of one of the pairs in a first rotational direction results in movement of the other pair in the counter direction by substantially the same angle. Each of the arms carries at least one movable marking indicator 50, 53. A user-operable locking mechanism is on or associated with the handle, the locking mechanism being configured selectively to prevent and enable rotation of the arms.

FIELD OF THE INVENTION

This invention relates to an alignment tool suitable for use in marking the position of holes to be made in a surface, such as a wall.

BACKGROUND OF THE INVENTION

When fixing an object to a wall using screws or nails, markings or pilot holes are usually made in advance of drilling and/or inserting the screws or nails.

In order to mark at least two horizontally-level points, it is usually necessary to employ a spirit level to establish a horizontal line, and then a ruler to set the markings at the required distance either side of a centre point.

This is a cumbersome task, requiring multiple tools, and often results in errors. Further, if more than two markings or holes are required, e.g. four points, equidistant apart in the upper and lower horizontal, the task becomes even more difficult.

One way in which relatively accurate marking can be achieved is by providing a paper template which sets-out the exact marking points for a particular fixture, which template is then laid-up to the wall so that marks can be made through the paper. The template is however non-adjustable, in that it caters for a specific fixture, and can only be used for that purpose once or a limited number of times.

SUMMARY OF THE INVENTION

A first aspect of the invention provides an alignment device for use in marking a surface, the device comprising:first and second longitudinal arms, each rotatably connected to a hub or handle, each arm carrying a scale or an indicator element; anda user-operable locking mechanism configured selectively to prevent and enable rotation of the arms.

The arms may be rotatably connected to a handle and the locking mechanism may be on or associated with the handle.

Each arm may carry an indicator element or elements movable relative to the arm along at least part of its length.

The first and second arms may be connected to a mechanism configured such that rotational movement of one arm in a first direction is effective to move the other arm by the same amount in the counter direction.

The mechanism may be a linkage mechanism comprised of a pair of linkage arms each connected at one part to a respective one of the longitudinal arms and at another part connected to each other.

The locking mechanism may comprise a screw/clutch plate arrangement selectively movable between a locked position in which it applies a force onto the arms to hinder rotation and an unlocked position to release said force to permit rotation.

The locking mechanism may comprise a lever provided on the handle selectively movable between a locked position and an unlocked position, the lever in the locked position being arranged to apply a force onto the arms to hinder their rotation and in the unlocked position to release said force to permit rotation.

The handle may comprise a rear part to which the arms are connected and a front part shaped and dimensioned to provide a hand grip, the lever of the locking mechanism being provided on said hand grip part. The lever may be located within a recess provided on the hand grip part and mounted so as to be substantially flush with the exterior of the hand grip part when locked. The lever may be a trigger-type lever provided on or in the front part of the hand grip.

The device may further comprise at least one spirit level. The or each spirit level may be on or associated with the handle. The device may comprise first and second spirit levels, one oriented vertical and the other horizontal.

Each arm may be formed of first and second portions, the first arm portion being connected to the handle and the second arm portion being telescopically mounted with the first arm portion to enable the arm's length to be extended.

The first arm portion may comprise a slotted sleeve within which the second arm portion is telescopically located.

The device may further comprise an extension locking mechanism provided on the second arm portion selectively to prevent and allow telescopic movement between the portions.

The indicator element may be provided by an aperture formed at or near the free-end of the second arm portion.

First and second indicator elements may be provided, one on each of the arm portions.

The indicator element on the first arm portion may be a slider, part of which is located within a further slot on said arm portion. The slider may comprise a slider lock configured to selectively lock the position of the slider relative to the arm.

The device may comprise two pairs of arms, the arms of each pair being connected and diametrically opposed either side of the handle.

A second aspect provides an alignment device for use in marking a surface, the device comprising:a pair of longitudinal arms, each rotatably mounted in the region of their longitudinal centres to a rotational mechanism provided in or on a hub or handle, the rotational mechanism being arranged such that, in use, movement of one of the pairs in a first rotational direction results in movement of the other pair in the counter direction by substantially the same angle, each of the arms carrying a scale or at least one movable marking indicator.

Each pair of arms may carry a scale or movable marking indicator either side of the hub or handle.

The device may further comprise a user-operable locking mechanism, the locking mechanism being configured selectively to prevent and enable rotation of the arms.

A further aspect provides an alignment device for use in marking a surface, the device comprising: a plurality of arms movably connected to a hub, movement of one of the arms causing in use movement of the other arm(s) in a predetermined motion, each of the arms carrying a scale or marking indicator. Four arms may be provided. The four arms may comprise two pairs of arms, with each pair being formed of two integrally formed or joined arms.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The embodiment described herein is an alignment tool1for use in marking fixture positions on a surface, such as a wall. In particular, the tool1allows pairs of holes to be marked accurately with a particular user-settable spacing between the holes along a level horizontal and/or vertical axis. Up to four markings can be made in the embodiment described.

Referring toFIGS. 1 and 2, the alignment tool1comprises four arms2-5connected to a handle6which acts as a hub about which the arms can rotate. The first and third arms2,4are attached at their distal ends, as are the second and fourth arms3,5, as is more clearly seen in the reverse view ofFIG. 2.

The arms2-5are therefore arranged as first and second pairs2,4and3,5with a shallow S-bend between the arms, so that the arms of each pair are rigidly linked and generally (but not precisely) diametrically opposed.

In this case, each pairing2,4and3,5is formed of an integral strip of metal material.

Each arm pairing2,4and3,5is rotatably connected to the handle6via a bearing7which rotates about an inner axle. A mechanical scissor-type linkage9is provided such that an angular rotation (α) of one arm pairing2,4in one direction causes the same angular rotation (−α) of the other arm pairing3,5the counter direction.

Other than when the arms2-5are in a storage position, as shown inFIG. 3, they will assume a symmetrical “X” shaped configuration, examples of which is shown inFIGS. 1 and 2.

The first linkage arm10is connected at one end via a rotatable joint to part of the third arm4, and the second linkage arm11via a rotatable joint to the fourth arm5. The other ends of the linkage arms10,11are rotatably connected at a common point to an external part12of a sliding component, this external part extending into a vertical slot13(seeFIG. 4) within the rear of the handle6where it is connected to an internal part of the sliding component.

Referring toFIGS. 5aand 5b, which show inside the handle6for respective different positions of the arms2-5, the internal sliding component14comprises a metallic member having two parallel vertical bores which locate closely around a pair of parallel bars16; the sliding component is therefore accurately guided along the vertical axis when any one of the arms2-5is moved by user force and ensures the arms of the other pairing move by the same angle in the counter direction.

Referring toFIG. 6, the handle6is generally U-shaped, with a rear part15providing a housing for part of a locking mechanism, to be described below, as well as supporting the above-described bearing7and linkage9. Extending forwardly, and then downwardly from the housing15is a hand grip17, shaped and dimensioned to be gripped in one hand, with a channel19defined between the housing and grip within which the fingers of one hand can locate in use.

An aperture21is formed within the front surface of the grip17within which is housed a trigger lever23which forms part of the locking mechanism.

In overview, the locking mechanism locks the arms2-5against rotational movement until unlocked. Unlocking is effected by pushing the trigger23inwards, into the aperture21, at which point the arms2-5are free to rotate. The locking mechanism (and therefore the trigger23) is biased into the locking position such that the arms2-5are locked against rotation unless force is applied to the trigger.

Thus, in use, the user grips the grip17, presses the trigger23, and rotates one arm pairing2,4or3,5to the desired angle which effects counter rotation of the other pairing in a symmetrical manner to the same angle. The trigger23is then released or pulled back to lock the arms2-5at the desired angle.

Referring toFIG. 7, a cross-sectional view of the tool1is shown with a cutting plane that passes through the central, vertical axis, including that of the handle6. The locking mechanism can be realised using any known type, but here a friction brake is employed to prevent movement of the arms2-5when the trigger23is in the (shown) locked position. At the upper end of the trigger23is a cam portion31having a shape that abuts, and applies a rearwards force onto a socket-shaped member33which surrounds the central axle30. Between the socket-shaped member33and a rear wall inside the housing15is a tube34that also surrounds the axle30and, in the locked configuration, applies a compressive force to the arms2-5between it and the bearing7which is fixed in place. In the unlocked configuration (not shown) the cam portion31is shaped such as to release the pressure applied by the tube34and so the arms2-5can rotate.

Referring back toFIG. 6, an angular protractor-like scale25is marked on one of the arms2with alignment markings arranged such that the shown angle is achieved by moving the arm until the corresponding marking is parallel with the vertical side of the housing15. Only one scale25is needed because all arms2-5will assume the required angle when the first arm2is moved to the correct angle, but additional scales can be provided on one or more of the other arms3-5.

A bubble/spirit level27is mounted to the handle6; in this case, two spirit levels (one horizontal and one vertical) are provided as a T-shaped component mounted to the top of the handle on the housing15. As will be known, the horizontal level provides a visual indication of when the tool1is level along the horizontal, whereas the vertical level provides a visual indication of when the tool1is plumb. At least a horizontal level should be provided.

Referring toFIGS. 8 and 9, each arm2-5is generally planar in form, on the rear surface at least, so that when the tool1is offered up to a wall, the arms rest on the wall, substantially flush therewith.

Further, each arm2-5is telescopically extendible. Taking the second arm3as an example, it comprises (a) a first longitudinal arm section3awhich is the part rotatably connected to the handle6and (b) a second, inner arm section3bthat can move relative to the first arm section, axially, to extend overall length.

The first arm section3acomprises a blade part40and a sleeved or slotted section42within which the inner arm section3blocates and slides within, unless locked. The inner arm section3bis locked in place relative to the sleeved section42by means of a cam lock lever45provided at the proximal end of inner arm section3b, and best viewed with reference toFIG. 6.

A marking indicator50is provided at the distal end of the inner arm section3b, in the form of an aperture with a frusto-conical wall, which in use allows and directs a pen, pencil or other marking implement to a precise position for marking a surface. A slider marking indicator may be provided, additionally or alternatively, which may be lockable.

The sleeved/slotted section42is open, in the sense that it has a slot running along its length which exposes a toothed strip47on the inner arm section3b. This permits selective movement and locking of a further marking indicator53associated with the first section3a.

This marking indicator53comprises a tapered marking notch60carried on a slider mounted within a narrow longitudinal slot55on the upper edge of the first arm section3a. The slider has a window56which exposes a calibrated lengthwise scale underneath. Beneath the window56is a rocker lock switch63which enables selective locking of the indicator53to the toothed strip47of the inner section3b.

The same configuration of telescopic arm sections applies to the other arms2,4,5, as will be appreciated, and further explanation is not required.FIG. 8shows how the inner arm sections3bcan be extended.

As indicated inFIG. 9, the scale on each first arm section (e.g.3a) extends to 280 mm from the central datum point. If this is sufficient, then the inner arm section3bcan remain locked in its non-extended state (as shown inFIG. 1, for example) and the outer indicator53moved to set the required marking position on each arm. If a greater length is required, the inner arm section3bis unlocked and can slide outwards, as inFIG. 8, with the additional offset being indicated using the proximal end of said inner arm section. When the desired offset is achieved, the inner arm section3bis locked within the outer arm section3aand the indicator50used for marking.

The arrangement of the blade and slotted sections40,42of upper arms2,3may be opposite to that of the lower arms4,5. This is so that, when in the storage configuration indicated inFIG. 3, for example, the relatively thin blade parts40overlap one another in the manner of scissor blades to keep the tool1compact, with the slotted parts42adjacent/abutting.

Overall, the tool1advantageously allows a user to accurately mark two or four level points on a surface, e.g. prior to drilling. In use, the user manually sets two or four points so that they will be of a required equal distance apart in the upper and/or lower horizontal, with the spirit level used to ensure the tool is level and plumb.

The tool1is designed to be compact and easy to use, employing a relatively simple selective locking mechanism which ensures accuracy. The arm lengths can be extended in 1 mm increments, but in the storage condition, e.g. shown inFIG. 3, the tool1is of a similar size and shape to a conventional spirit level (approximately 900-1200 mm). It can be made of lightweight material so that it can be used in one hand. Aluminum extrusions and self-lubricating nylon injection moulded plastics parts can be used, e.g. the former for the outer arm sections and the latter for the inner arm sections.

The arms2-5are made so as not to flex (at least not significantly) when marking at full length.

The arms2-5can open out to a maximum of 90 degrees. The linkage mechanism ensures that movement of just one arm results in a corresponding and accurate movement of the others.

The tool advantageously allows four points, e.g. holes, to be marked on a surface, e.g. aligned vertically and horizontally.

It will be appreciated that the above described embodiments are purely illustrative and are not limiting on the scope of the invention. Other variations and modifications will be apparent to persons skilled in the art upon reading the present application.

Moreover, the disclosure of the present application should be understood to include any novel features or any novel combination of features either explicitly or implicitly disclosed herein or any generalization thereof and during the prosecution of the present application or of any application derived therefrom, new claims may be formulated to cover any such features and/or combination of such features.