An accessory for a level.

FIELD OF INVENTION

This invention relates to an accessory for a level, for example for fitting to a level of the type used by carpenters.

BACKGROUND

It is known for carpenters to use levels to determine whether a part of a building or other construction is vertical or horizontal. However, often a level needs to be supplemented by another device in order to obtain the sort of measurements or readings a builder needs in the course of a construction job. It can be difficult or inconvenient having to grasp and manipulate these other devices while at the same time doing this with the level.

OBJECT

It is an object of preferred embodiments of the invention to at least go some way towards addressing the above problem. However, it should be understood that the object of the invention per se is simply to provide the public with a useful choice. Therefore, any objects, advantages or benefits applicable to any preferred embodiments should not be taken as a limitation on any claim expressed more broadly.

DEFINITIONS

The term “comprises” or “has”, if and when used in this document in relation to one or more features, should not be seen as excluding the option of there being additional unmentioned features. The same applies to derivative terms such as “comprising” and “having”.

SUMMARY OF INVENTION

According to one aspect of the invention there is provided device in the form of a level or an accessory for a level, comprising: a) a connective portion; and b) a pair of locking extensions located substantially in the connective portion and each being subject to a biasing force that urges a part of each extension to a respective position outside the connective portion; formed so that the connective portion is adapted to sleeve-fit into a complimentary body of a second device such that the locking extensions extend into apertures of that body to interlock the two devices.

Optionally the connective portion is substantially cylindrical.

Optionally the locking extensions comprise locking pins and the biasing force is provided by a spring.

Optionally the level or accessory comprises a locking head that is biased by the spring towards the pins to contact them such that the locking head causes a portion of each pin to extend outside the connective portion.

Optionally the pins each comprise a shoulder and the locking head has curved sides, the pins and locking head are arranged such that when the spring is at a default position the curved sides of the locking head contact a respective one of the shoulders to move outer ends of the pins out of the connective portion.

Optionally the level or accessory comprises a shaft secured to the locking head at one end and secured to a handle at the other end, the arrangement being such that the handle can be moved to temporarily overcome locking force from the spring to move the head away from the pins such that each pin is free to move inwards to a non-locking disposition.

Optionally pulling the handle causes the spring to move to a state of increased compression.

Optionally the locking head is spring biased to move in a direction that is substantially at right angles to the pins.

Alternatively the locking extensions are in the form of buttons that are subject to magnetic repulsion force which seeks to move them apart.

Optionally each button consists of, comprises, or is associated with a magnet and in each case the magnets are arranged so that like poles are nearest to one another to cause the repulsion force.

Optionally each magnet is surrounded by a bush which serves to keep the magnets in place. Optionally each button is retained in the engagement portion by interference from one or more inwardly extending retainer portions.

Optionally the buttons can be pushed by hand to temporarily overcome the magnetic repulsion force and move into an unlocked disposition where they are more within the connective portion, and such that when the push force is relaxed, they automatically return to a locking disposition where a portion of each button extends outside the connective portion.

Alternatively the locking extensions comprise a pair of balls and the biasing force is generated by a spring disposed between the balls to urge a portion of each ball to a locking position outside the connective portion.

Optionally the balls can be pushed by hand to temporarily overcome the biasing force and move into an unlocked disposition where they are more within the connective portion, and such that when the push force is relaxed, they automatically return to a locking disposition where a portion of each ball extends outside the connective portion.

Optionally the level, or the accessory for a level, is sleeve-fitted into the second device and the locking extensions are engaged in apertures of the second device to prevent level or accessory from sliding out of the second device until the protrusions are forced by hand inwards to a non-locking disposition.

Optionally the first mentioned device is an accessory for a level and the second device is a level.

Optionally the device is such that it may be defined by the first ‘summary of invention’ paragraph in combination with any one or more of the subsequent optional summary statement paragraphs above.

DRAWINGS

Some preferred embodiments of the invention are described below by way of example and with reference to the accompanying drawings, of which

Figure 1 is an isometric view of a builder’s level about to be fitted with an accessory;

Figure 2 is an isometric view showing the level and accessory from an alternative angle; Figure 3 is a longitudinal cross-sectional view illustrating engagement between the level and the accessory;

Figure 4 is a longitudinal cross-sectional view illustrating an another type of engagement between the level and the accessory; and

Figure 5 is a longitudinal cross-sectional view illustrating a further type of engagement between the level and the accessory.

DETAILED DESCRIPTION

Referring to Figures 1 and 2, the builder’s level 1 comprises a spirit vial 2 (as is normal for levels) and a hollow body 3. As shown, one end of the body 3 has a pair of apertures 4, 5, one above the other. The accessory 6 has a connective portion, in this case comprising a cylindrical arm 7. The outer end of the accessory 6 has retractable protrusions 8, 9 each arranged to move at least partially into the arm 7 and fit into a respective one of the level’s apertures 4, 5. Figure 2 shows the level 1 just before being interlocked with the accessory 6. In this case the accessory is T-shaped so that when connected to the level it gives set square functionality.

Figure 3 illustrates detail of the manner in which the level 1 and accessory 6 interlock according to one embodiment of the invention. As shown, the arm 7 of the accessory sleeve-fits into the body 3 of the level. In this embodiment the accessory’s protrusions 8, 9 are in the form of locking pins 10, 11. The pins are narrower at their inner end 12 and wider at their outer end 13. When in their locking disposition the outer end of each pin extends into and through a respective one of the level’s apertures 4, 5. The pins 10, 11 are caused to remain in that position by a locking head 14 which is biased to sit between them by a partially compressed spring 15. The double headed-arrows in the pins indicate their ability to move inwards and outwards.

As also shown in Figure 3, a shaft 16 is fixed to the locking head 14 at one end, passes through the spring 15, and at its opposite end is fixed to a handle 17. The arrangement is such that one end of the spring 15 presses against the locking head 14 and the other end presses against a fixed internal wall 18 of the accessory, which may or may not be fitted with a washer 19. The spring 15 urges the locking head 14 to engage with and push the accessory’s pins 10, 11 apart so that they locate in the level’s apertures 4, 5.

When it is desired to release the accessory from the level, the handle 17 can be hand-pulled to move the locking head 14 out of engagement with the pins 10, 11 , so that they are able to be pushed by hand to move inwards of the accessory’s arm 7, i.e. out of the level’s apertures 4, 5. With the pins 10, 11 in this disengaged disposition, the accessory’s arm 7 can be slid out of the level’s hollow body 3 to separate the level and accessory. Releasing the pulling force on the handle 17 causes the spring 15 to push the locking head 14 back into engagement between the pins 10, 11 so that they revert to their outwardly extending ‘locking’ disposition.

Still with Figure 3, optionally each pin has an inner lip 10b, 11 b which catches against a complimentary shoulder 7a, 7b of the arm 7 to prevent the pins 10, 11 from falling from the arm 7 when it is disconnected from the level 1 .

In some embodiments of the invention the pins 10, 11 may be connected by a spring extending between them (not shown) and which urges them inwards, towards one another, but where the force of that spring is overcome by the locking head when it pushes the pins apart and into the apertures 4,5 for locking.

Still with Figure 3, the accessory’s locking pins 10, 11 are each generally cylindrical with an inner shoulder 10a, 11 a that runs along the curved leading side parts 14a of the locking head 14, i.e. as the pins are pushed apart for locking to the level, and subsequently move closer together for release from the level.

Figure 4 illustrates an alternative embodiment of the accessory 6 in terms of the way it locks into the level 1 in a sleeve-fit similar to that described above. However, in this version the accessory’s protrusions 8, 9 are in the form of push buttons 20, 21 , and the arm 7 of the accessory 6 contains a cylinder 22 that houses the buttons. The inner end of each button is fixed to a respective magnet 23, 24 with a pair of plastic packers 25, 26 surrounding the magnet to help keep the magnets centered.

When in a locking disposition, the outer end 27 of each push button extends into and passes through a respective one of the level’s apertures 4, 5 to prevent sliding movement between the level 1 and the accessory 6. The buttons 20, 21 are biased to remain in that position by magnetic repulsion force generated by the magnets 23, 24. In this regard the magnets are arranged so that their like poles face, or are immediately adjacent to, one another, i.e. North- North or South-South, and therefore seek to push the buttons 20, 21 away from one another. The buttons 20, 21 are each shaped such that their inner end 28 is in each case retained in but able to move along the cylinder 22. When it is desired to release the accessory 6 from the level 1 , the buttons 20, 21 are pushed inwards by hand so that their outer ends 27 move out of the level’s apertures 4, 5 and into the accessory’s cylinder 22. The hand force therefore overcomes the repelling force of the magnets 23, 24. With the buttons in this disengaged disposition, the accessory’s arm 7 can be slid out of the level’s body 3 to separate the accessory 6 and the level 1 . Once the accessory’s arm is free of the level, the repelling magnetic force causes the buttons 20, 21 to revert back to their extended ‘locking’ disposition.

As illustrated, the wall of the cylinder 22 has an inward retaining rim 22a for each button, and these serve to keep the buttons in the arm 7. More specifically, each button has a constricted medial part between its wider ends 27, 28. In each case the rim 22a interferes with the lower end 28 of each button to prevent it from sliding past the rim.

Figure 5 illustrates a further embodiment of the accessory 6 and the manner it engages with the level 1 . In this version the accessory’s protrusions 8, 9 are in the form of a pair of balls 29, 30 disposed in a cylinder 31 inside the accessory’s arm 7. As shown, a partially compressed spring 32 sits between the balls 29, 30 and subjects them to a force that urges/bias’s them apart.

When in their locking disposition, part of each ball extends into and engages with a respective one of the level’s apertures 4, 5, causing the accessory’s arm 7 to remain locked within the level’s body 3 in a sleeve-fit arrangement. The balls are not able to escape the cylinder 30 as the level’s apertures 4, 5 are not wide enough to enable the balls to pass completely through. However, enough of each ball is able to protrude into the apertures 4, 5 to prevent the arm 7 of the accessory sliding out of the level’s body 3.

The diameter of the balls is larger than the diameter of the apertures 4,5. The arrangement is such that the when the spring exerts its force, the widest part of the ball remains within the accessory’s arm 7, which in turn prevents the accessory’s arm from sliding out of the level 1 .

When it is desired to release the accessory 6 from the level 1 , the balls 29, 30 are pushed by hand inwards to overcome the force of the spring so that they move inwards, out of the level’s apertures 4, 5. With the balls in this disengaged position, the arm 7 of the accessory can be slid out of the level 1 to separate the two. Once the accessory’s arm 7 is free, the spring forces the balls into their extended ‘locking’ disposition. In some further embodiments of the invention the parts that enable the level and accessory to interlock may be in reverse. Put another way, the level may be without the apertures 4, 5, but there may be similar apertures in the arm 7 of the accessory. And in that case the protrusions 8, 9 (e.g., the pins, buttons, or balls) and associated parts may be located in the body 3 of the level rather than the accessory’s arm 7.

Optionally the accessory referred to for any of the embodiments above comprises a panel square to provide a straightedge at a right angle, wherein the level provides the baseline; a clamp to temporarily hold the level securely in place so that it can be used as a guide; an angle finder to help determine an angle from the level’s plane; or a joiner to attach two levels of different lengths. The accessory may also comprise of a 90° attachment or a 45° attachment to check for example roof angles.

While some forms of the invention have been described by way of example, it should be appreciated that modifications and improvements can be made without departing from the scope of the following claims.

In terms of disclosure, this document envisages and hereby posits any feature mentioned herein in combination with any other feature or features mentioned herein, even if the combination is not claimed.