Brick cutting device

The present invention is concerned with the cutting of brittle blocks of material, and in particular, but not limited to, masonry items such as bricks. By "bricks" we mean blocks of masonry material such as house bricks, paving stones, block paving and stone slabs.

Many structures and buildings are constructed with bricks of varying sizes and materials. In areas where a wall or path edge, or particular shape of a structure is desired, the bricks need to be individually cut so that they do not protrude from the lines of the structure. Similarly when constructing paving, it is often necessary to cut bricks to a required shape in order to fit them amongst adjacent bricks.

Bricks are traditionally cut using a hammer in conjunction with a sharp chisel-like implement to direct the impact force of the hammer over a cutting edge of the chisel. Due to the small surface area of the chisel cutting edge, high stresses are produced at the face of the brick as the hammer impacts and the brick fractures throughout its thickness. This fracturing occurs as bricks are constructed from brittle materials which tend to crack under high stresses (i.e. there is very little deformation before failure).

There are several problems with this method. As a high energy impact event is used, it is possible for chips of brick material to fly off and injure the user. Additionally, great accuracy is required to strike the chisel accurately, and misplacement can result in injury if the hammer strikes the hand holding the chisel. Furthermore, accuracy of the cut is difficult to guarantee as if the chisel is tilted it may move along the surface of the brick during the impact event.

Alternative methods of brick cutting exist, which use a guided blade as an alternative to the chisel, but still rely on a blow to cause the fracture. As such, these alternatives still rely on a high energy impact event and the above disadvantages are still present. Additionally, complex mechanical devices such as circular saws may be employed to

but bricks, however these devices are noisy, produce a significant amount of brick dust and debris and require a power supply.

It is an object of the current invention to overcome one or more of the above disadvantages.

According to a first aspect of the present invention there is provided a cutter for cutting bricks comprising: a first jaw, a second jaw positioned substantially opposite the first jaw and defining a receiving area therebetween for receiving a brick, a first cutting formation for engagement with a brick defined on one of the first jaw and the second jaw, and a frame connecting the first jaw and the second jaw, a clamping means comprising a lever pivotably mounted to the frame about a pivot axis, the clamping means further comprising a first threaded member arranged to engage the lever at a first position away from the pivot axis, the first threaded member further engaging the frame such that rotation of the first threaded member causes a rotation of the lever about the pivot axis, in which a second position of the lever away from the pivot axis is arranged to urge the first jaw towards the second jaw upon the rotation of the lever to provide a cutting force.

Providing a lever allows a force applied to the actuator to be amplified to provide the cutting force.

According to a second aspect of the present invention there is provided a cutting head for a brick cutting device comprising a cutting formation defined as a first apex of a polygonal cutting head, which polygonal cutting head is mounted in a cutting head mount such that it can be selectively repositioned to present a further cutting formation defined as a further apex of the polygonal cutting head.

As such, multiple cutting edges can be provided on a single head.

According to a third aspect of the present invention there is provided a cutting head for a brick cutting device comprising a hydraulic ram having an actuating piston with a first working area and an actuated piston having a second working area, the first working area being smaller than the second working area, an actuator connected to the actuating piston to urge the actuating piston in the direction of the actuated piston, a first jaw having a cutting surface for brick cutting, the first jaw being connected to the actuated piston such that application of a force to the actuator results in a cutting force at the first jaw in a cutting direction to cut a brick.

Providing a hydraulic ram allows a force applied to the actuator to be amplified to provide the cutting force. As such, smaller sized actuators may be used. This feature also allows manual actuation to cut particularly hard bricks which would not normally be cuttable with the level of force generated manually.

According to a fourth aspect of the present invention there is provided a cutter for cutting bricks comprising: a first jaw, a second jaw positioned substantially opposite the first jaw and defining a receiving area therebetween for receiving a brick, a first cutting formation for engagement with a brick defined on one of the first jaw and the second jaw, and clamping means connecting the first jaw and the second jaw and configured to move the second jaw towards the first jaw.

Providing a clamping means allows progressive movement of the jaws such that a slow, controlled application of force can be provided as opposed to the high speed, high energy impact force of the prior art.

According to a fifth aspect of the present invention there is provided a method of cutting bricks comprising the steps of: providing a first jaw, providing a second jaw positioned substantially opposite the first jaw, providing a first cutting formation for engagement with a brick on one of the first jaw and the second jaw, inserting a brick between the first jaw and the second jaw, progressively clamping the first jaw and the second jaw by moving the second jaw towards the first jaw to cut the brick.

A brick cutter in accordance with the present invention will now be described with reference to the accompanying figures in which:

Figure 1 is a front view of a first embodiment of a brick cutter in accordance with the present invention;

Figure 2 is a front view of the brick cutter of figure 1 in use; Figure 3 is a side section view of a part of the brick cutter of figures 1 and 2 in use along line IH-III;

Figure 4 is a side section view of a part of the brick cutter of figures 1 and 2 in use along line IV-IV;

Figure 5 is a top view of the brick cutter of figure 1 in use with a brick in a first configuration;

Figure 6 is a top view of the brick cutter of figure 1 in use with a brick in a further configuration; Figure 7 is a side view of a second embodiment of a brick cutter in accordance with the present invention;

Figure 8 is a front view of the brick cutter of figure 7; Figure 9 is a front view of a part of the brick cutter of figure 7; Figure 10 is a front view of a part of the brick cutter of figure 7; Figure 11 is a top view of the brick cutter of figure 7;

Figure 12 is a side view of a third embodiment of a brick cutter in accordance with the present invention;

Figure 13 is a side view of the brick cutter of figure 12 in an alternative configuration;

Figure 14 is a top view of the brick cutter of figure 12;

Figure 15 is a perspective view of a part of a brick cutter in accordance with the present invention;

Figure 16 is a perspective view of a part of a brick cutter in accordance with the present invention,

Figure 17 is a side section view of a brick cutting head in accordance with a fourth embodiment of the present invention in an initial position; Figure 18 is a side section view of the brick cutting head of figure 17 in an adjusted position;

Figure 19 is a side section view of the brick cutting head of figure 17 in an actuated position;

Figure 20a is a top view of a fourth embodiment of a brick cutter in accordance with the present invention;

Figure 20b is a side section view of the brick cutter of figure 20a along line XX-XX;

Figures 21a and 21b are side section views of parts of the brick cutter of figure 20a in operation; Figure 22 is a side section view of the brick cutter of figure 20a in an actuated state;

Figure 23 is a side section view of a fifth embodiment of a brick cutter in accordance with the present invention;

Figure 24 is a side section view of a sixth embodiment of a brick cutter in accordance with the present invention;

Figure 25 is a perspective view of a part of a seventh embodiment of a brick cutter in accordance with the present invention; and

Figure 25a is a perspective view of a part of the brick cutter of figure 25.

Figures 1 to 6 show a brick cutter 10 comprising a base 12, a clamping member 14, a first threaded member 16, a second threaded member 18 and a pair of nuts 20.

The base 12 is prismatic and constructed from a metal material such as steel. The cross section of the base 12 is generally rectangular and comprises an upwardly projecting protrusion 22 on which is defined a lower cutting edge 24. At opposing ends of the base 12 are situated blind bores 26, 28.

The clamping member 14 is substantially similar to the base 12 but inverted, and as such comprises a downwardly projecting protrusion 30 on which is defined an upper cutting edge 32. Open bores 34, 36 are defined at opposing ends of clamping member 14, of slightly larger diameter than the blind bores 26, 28.

The first and second threaded members 16, 18 are identical and are generally cylindrical with threaded portions 38, 40 formed at the upper ends thereof and extending partially along the length of the members 16, 18. The threaded portions 38, 40 are formed to be received in nuts 20.

In the assembled brick cutter 10, each of the non-threaded ends of the threaded members 16, 18 are placed into the blind bores 26, 28 of the base 12. The threaded members 16, 18 and blind bores 26, 28 are dimensioned such that an interference fit is obtained therebetween to retain the members 16, 18. Alternatively, the threaded members 16, 18 may be welded to the base 12.

The clamping member 14 is then positioned with the upper cutting edge 32 facing downwards such that the threaded portions 38, 40 of the members 16, 18 pass through the open bores 34, 36. Nuts 20 are then secured onto the threaded portions 38, 40.

In use, a brick 8 is positioned between the base 12, and the clamping member 14 as shown in figures 1, 2 and 5. The brick may be positioned in any orientation to achieve the desired cut as shown in figure 6.

The clamping member 14 then rests on the brick 8 as shown in figure 2. When the brick 8 is positioned as desired, with an intended cutting line 42 coincident with the vertically opposed cutting edges 24, 32, nuts 20 are tightened using an appropriate tool (e.g. spanner, wrench, socket). This progressive tightening urges the nuts down

the threaded portions 38, 40 and as such applies a clamping force onto the brick 8 via cutting edges 24, 32. It should be noted that the system will not be driven back by the clamping force experienced by the brick due to the presence of the threads, rather the load application is progressive, and as such the force may be applied in stages, releasing the tool periodically if desired.

As the tightening continues, the brick 8 begins to fracture at fracture regions 42, 44 adjacent to cutting edges 24, 32. Eventually, the stress at the fracture regions 42, 44 will be sufficient to propagate a crack throughout the brick and cut it into two portions. The wedge shape of the protrusions 22, 30 assists the crack propagation by applying a horizontal force component during cutting.

Turning to figures 7 to 11 a second embodiment of a brick cutter 100 is shown. The brick cutter 100 comprises a body 102, an upper jaw 104, a lower jaw 106 and a handle 108.

The body 102 is C-shaped comprising a back portion 110, an upper portion 112 and a lower portion 114 and constructed from a metal material such as steel. A threaded through bore 116 is formed in a free end of the upper portion 112. A countersunk through bore 118 is formed in a free end of the lower portion 114. The bores 116, 118 are coaxial. A threaded blind bore 120 is also defined at an upper end of the back portion 110.

With reference to figure 9, the upper jaw 104 comprises a clamping member 122 which is prismatic and generally rectangular in cross-section and comprises an upper wedge-shaped protrusion 124 defining a cutting edge 126. A blind bore 128 is formed in a surface of the clamping member 122 opposite to the protrusion 124. A further threaded bore 129 is formed in a side face of the clamping member 122 and open to a sidewall of the blind bore 128.

The upper jaw 104 further comprises a bolt 126 with a hex head portion 128, a threaded portion 130 and a locking portion 132. Locking portion 132 is generally cylindrical with a circumferential groove 134 formed therein.

Assembly of the upper jaw 104 takes place by placing the locking portion 132 into the blind bore 128 and inserting a grub screw into the further threaded bore 129 such that it engages with the circumferential groove 134. The bolt 126 is then able to rotate relative to the clamping member 122.

With reference to figure 10, the lower jaw comprises a clamping member 136 substantially similar to clamping member 122 but inverted, and as such comprises protrusion 138 defining a lower cutting edge 140. The clamping member 136 has a blind threaded bore 142 machined into a bottom face opposite the protrusion 138.

The handle 138 is a generally cylindrical member comprising a coaxial blind threaded bore 144.

When assembled, the upper jaw 104 is mounted to the body 102 by threading the bolt 126 into threaded bore 116 in the body 102. The upper clamping member 122 is then assembled to the bolt 126 as described above. Note that when assembled, the clamping member 122 abuts a shoulder 146 of the body 102 and as such is constrained from rotation but able to slide vertically.

The lower jaw 106 is mounted to the body by aligning threaded bore 142 with countersunk bore 118 and securing with an Allen key bolt 148. Finally, the handle 108 is attached by inserting a threaded member 150 into threaded bore 144 and threading into bore 120 as shown in figure 7.

In use, a brick 98 is inserted between the cutting edges 126, 140 as shown in figures 7 and 8. A tool such as a spanner, wrench or socket can then be used to rotate the hex head 128. Such rotation axially moves the bolt 126 and hence the upper clamping member 122 towards the lower clamping member 136. As the bolt is free to rotate relative to the upper clamping member 122, no rotation of the clamping member 122 is seen due to its abutment with shoulder 146. As rotation progresses, the brick fractures in a similar manner to that discussed with respect to brick cutter 10. The

handle 108 may be used to manually counteract the torque applied to the hex head 128.

The rotational force to the head 128 may be provided by a motor with an appropriate coupling, for example and electric or hydraulic motor. Alternatively, the threaded portion 130 may comprise the output shaft of such a motor.

Referring to figure 11 the brick cutter 100 may comprise a base 150. Base 150 may have markings 152 defined thereon with which to align the brick 98 with respect to the brick cutter 100 to achieve the desired orientation of cut 154.

Referring to figures 12 to 14, a brick cutter 200 is substantially similar to brick cutter 100 with common features labelled 100 greater. Brick cutter 200 additionally comprises through bore 260 and coaxial blind bore 262 formed in the upper and lower arms 212, 214 of the body 202 respectively.

Brick cutter 200 also comprises a positioning device 264 comprising a plate 266 and a pin 268 rotatably attached therethrough. The pin 268 has a hex head 270. The pin 268 may be keyed or splined to the plate 266 such that the two components rotate together.

When assembled, the pin passes through bores 260, 262 as shown in figure 12 and 13 with the hex head 270 projecting as shown. There is a tight fit between the pin 268 and the blind bore 262 such that the pin, when rotated, stays in position. The positioning device 264 can therefore be used to set up an desired angle of cut 254, and when inserted the brick 98 abuts the plate 266 to provide that angled cut. Therefore repeated cuts can be made at the desired angle.

Figures 15 and 16 show different alternatives for the manufacture of the clamping portions 12, 14, 122, 136. A separate protrusion 302 may be attached to a base portion 300 as shown in figure 15 (for example if the cutting material is expensive, high hardness material). Alternatively, the protrusion 398 is machined from the body 399 as shown in hidden line in figure 16.

Numerous changes may be made within the scope of the present invention.

The clamping effect need not arise from an external hex head. An internal hex (Allen key), or other suitable formation (e.g. a spline) may be used to transfer torque.

Both jaws need not carry cutting edges, a single edge on either jaw may produce a crack through the brick. To assist crack propagation in the case of a single cutting edge, an indentation may be provided on the opposite jaw to increase the local stresses and set up 3-point bending in the brick. The indentation may take the form of a "V" shaped notch opposite to the cutting edge, or alternatively between a pair of raised protrusions either side of the cutting edge on the opposite jaw.

Different materials could be used to construct the device; such as steel, aluminium, various alloys.

Coatings (e.g. diamond) may be applied to the cutting edges to provide suitable hardness and wear resistance.

The positioning device may be linearly movable to produce different cut locations as well as angles. The positioning device may be as simple as a bolt passing through a threaded bore in back portion 210 and abutting the brick 98.

Figures 17 to 19 show a cutting head 300 of a brick cutting device which is similar to that of figure 7. An upper portion 302 is similar to the upper portion 112, and has a threaded through bore 304.

A hydraulic cylinder 306 has a cylindrical body 308 on which an external thread 310 is defined. The cylindrical body 308 also defines a stepped cylindrical through bore 312 having a first diameter section 314 and a second diameter section 316 separated by an annular shoulder 318. The first diameter section 314 is threaded proximate its distal end.

The hydraulic cylinder 306 further comprises an actuating piston 320, slideably mounted and sealed within the first diameter section 314. The actuating piston 320 has a threaded rod 322 extending therefrom. The threaded rod 322 has a handle 324 defined at an end opposite the actuating piston 320.

The hydraulic cylinder 306 further comprises an actuated piston 326, slideably mounted and sealed within the second diameter section 316. The actuated piston 326 has a shaft 328 extending therefrom. An upper jaw 330 is connected to the shaft 328, and is substantially similar to the jaw 104.

The cutting head 300 is assembled by threading the rod 322 into the first diameter section 314. A hydraulic fluid 332 is then added to the through bore 312 and the shaft 328 inserted to seal the hydraulic fluid 332 between the actuating piston 320 and the actuated piston 326.

In other embodiments, the shaft 328 may have a return mechanism such as a return spring to bias the shaft 328 into the cylinder 306.

In use, the upper jaw 330 can be adjusted near a brick 301 surface by rotating the cylinder 306 in the threaded bore 304. Significant adjustment of the system may therefore be made before cutting commences.

To cut the brick 301, the handle 324 can be rotated to advance the actuating piston 320 towards the actuated piston 326. As the hydraulic fluid 332 is substantially incompressible, the pressure urges the actuated piston 326 from the cylinder 306. Due to the difference in surface area contact between the actuating piston 320 and the actuated piston 326 an increase in the amount of force applied is seen at the upper jaw 330 compared to a non hydraulic threaded system (as per figure 7).

Although this is the case, the displaced distance of the actuated piston 326 is consequently less than that of the actuating piston 320. However large scale adjustments can be made by rotating the cylinder 306 instead.

Figures 20 to 22 show a fourth embodiment of a brick cutter 400. The brick cutter 400 comprises a body 402, an actuator assembly 404, an upper cutting assembly 406 and a lower cutting assembly 408.

The body 402 is substantially in the shape of a "C" and comprises a horizontally extending lower arm 410 defining a protruding support 412 extending from its upper surface. The lower arm 410 defines a semi -hexagonal recess 414 with an apex 416 of the hexagon at bottom dead centre.

The body 402 comprises a rib 418 extending vertically from the lower arm 410, which connects to an upper arm 420 extending substantially parallel to the lower arm 410. The upper arm 420 splits into a support fork 422 distal to the rib 418 before becoming unitary at an end 424 opposite to the rib 418.

The upper arm defines an upper cutting assembly receiving formation 426 on a face opposite the semi-hexagonal recess 414 of the lower arm 410.

Each leg of the support fork 422 comprises an upwardly extending lug 428, each lug 428 defining a concentric through bore 430.

The actuator assembly 404 comprises a lever arm 432 defining a first threaded through bore 434, a second threaded through bore 436 and a transverse pivot bore 438.

A main screw 440 is threaded into the first threaded through bore 434, and is substantially longer than the length of the first threaded through bore 434. The main screw 440 has a hex head 442. An adjustment screw 444 is threaded into the second threaded through bore 436 which also defines a hex head 446. The adjustment screw 444 is also substantially longer than the length of the second threaded through bore 436.

The upper cutting assembly 406 comprises an elongate cutter frame 448 defining a pair of oppositely extending lugs 450 proximate it centre. The cutter frame 448 defines a semi-hexagonal recess 452 with an apex 454 of the hexagon at top dead

centre (see figure 21a). The upper cutting assembly 406 comprises a top cutting head 456 substantially in the form of a hexagonal prism. The top cutting head 456 is retained in the cutter frame 448 by grub screws 458.

The lower cutting assembly 408 comprises a bottom cutting head 460 substantially in the form of a hexagonal prism, and substantially identical to the top cutting head 456.

The cutting heads 456, 460 are constructed from a hardened steel.

The brick cutter 400 is assembled by placing the bottom cutting head 460 into the semi-hexagonal recess 414 of the lower arm 410.

The upper cutting assembly 406 is them mounted into the upper cutting assembly receiving formation 426 and biased upwardly by springs 462.

The actuator assembly 404 is then pivotably mounted to the body 402 by passing a pivot pin 464 through the concentrically aligned through bores 430 and transverse pivot bore 438.

In use, a brick or slab 401 is placed between the cutting heads 456, 460. The upper cutting head 456 is then adjusted downwardly by rotation of the adjustment screw 444 against the bias of the springs 462 to contact the brick 401. Once the brick 401 is clamped between the cutting heads 456, 460, the main screw 440 is rotated clockwise (i.e. inwardly) via a tool on the hex head 442.

The clockwise rotation of the main screw 440 acts to rotate the lever arm 432 about the pivot pin 438 by virtue of the abutment of the main screw with the upper arm 420. The adjustment screw 444 then urges the cutter frame 448 and hence top cutting head 456 downwards against the brick 401. A non-actuated (hidden line) and an actuated (solid line) condition are shown in figure 21b.

With reference to figure 21b, the horizontal distance between the contact point between the main screw 440 and the upper arm 420 and the centre of the pivot pin 438

is Dl. The horizontal distance between the contact point between the adjustment screw 444 and the cutter frame 448 and the centre of the pivot pin 438 is D2.

Dl is engineered to be substantially larger than D2. The brick 401 is constructed from brittle material which will fail after a relatively low level deformation. As such, there is no need for the cutting head 456 to travel far. On the other hand, the cutting head

456 does need to apply sufficient force to fail the brick 401, which is significant. As such, a mechanical advantage is provided by the difference in Dl and D2 such that a relatively low (manually applied) torque can be applied at the main screw 440 resulting in a large cutting force at the cutting head 456.

The brick cutter 401 is shown in an actuated condition in figure 22, with a crack 403 propagated along the depth of the brick 401.

It will be noted that the adjustment screw 444 provides a method of quickly positioning the cutting head. Due to the ratio between Dl and D2 it would be impractical to move the cutting head large distances using the main screw 440.

Turning to figure 23, a simpler brick cutter 500 is shown substantially similar to that of figures 20a to 22, except with an abutment lug 544 instead of an adjustment screw 444.

Each cutting head 456, 460 can be rotated to present a different apex of the hexagonal prism to the brick 401. As such each cutting head utilises 6 cutting edges and as such can simply be rotated if one is worn or damaged.

As can be seen in figure 20b, the main screw 440 is positioned at an angle A to the horizontal in the non-actuated position. As the brick cutter 400 is actuated, angle A will increase (see figure 21b). The optimum angle for A is 90 degrees which provides the highest rotation of the lever arm 432 and the best contact conditions between the screw 440 and the upper arm 420. As such the starting angle A can be selected to rise to around 90 degrees as the top cutting head 456 contacts the brick 401.

It will be noted that as the main screw 440 is turned and the lever arm 432 rotates, the adjustment screw 444 will move along the surface of the cutter frame 448. The optimum position of the adjustment screw is over the cutting edge of the top cutting head 456. The starting position of the adjustment screw can also be selected such that it is at an optimum for the eventual cutting operation.

These values may be selected, for example, for a standard size brick or slab.

Referring to figure 24, a brick cutter 600 is shown in which the body 602 has been extended such that Dl is even larger than D2 and a larger mechanical advantage is provided.

Referring to figure 25 and 25a, a brick cutter 700 is shown in which a cutting head 702 is mounted to a body 704 via a substantially U shaped plate 706. The plate 706 comprises bores 708 to receive and retain the cutting head 702 and is slidable relative to the body 704 in a cutting direction D.

The cutting head is actuable via a lever arm 710 which operates similarly to the above embodiments and contacts a cutter support block 712 mounted to the cutting head 702. The lever arm 710 contacts the support block 712 via an adjustment screw 714 which passes through the plate 706 and the lever arm 710. As such, the position of the cutting head 712 can be adjusted and the adjustment screw 714 tightened.

Variations on the above embodiments are possible which fall within the scope of the present invention.

Either or both of the screw 440, 444 may have any type of head, and may be manually actuable by a T-bar for example.

The cutting heads 456, 460 may be any polygonal shape, for example triangles, squares, pentagons, hexagons, heptagons etc. and therefore provide any number of cutting edges.