CN108724479B

CN108724479B - Cutter for cutting flat plate or ceramic tile

Info

Publication number: CN108724479B
Application number: CN201810325440.2A
Authority: CN
Inventors: 文森佐·蒙托利; L·卡萨尔泰利
Original assignee: Brevetti Montolit SpA
Current assignee: Brevetti Montolit SpA
Priority date: 2017-04-13
Filing date: 2018-04-12
Publication date: 2021-10-19
Anticipated expiration: 2038-04-12
Also published as: ES2815499T3; EP3388214A1; IT201700041610A1; EP3388214B1; CN108724479A

Abstract

The present invention relates to a shear for cutting slabs or tiles. An engraving shears for ceramic tiles or slabs made of hard material comprising a pair of lever parts (1a, 1b) hinged to each other, the lever parts being provided, on two opposite sides of a hinge axis (2), respectively, with a handle portion (1a ', 1 b') and an end head (1a ", 1 b") carrying a cutting element in the form of a cutting wheel (4a, 4b) having a peripheral cutting edge, the cutting wheel (4a, 4b) being fixed in parallel with a fastening boss perpendicular to a lying plane of the pair of lever parts (1a, 1b), wherein the end head (1a ", 1 b") is L-shaped so as to define a fastening boss arranged offset with respect to the lying plane; and the end heads (1a ', 1 b') have opposite projections (5a, 5b), the projections (5a, 5b) extending in a direction connecting the centers of the cutting wheels (4a, 4b) all the way to a distance from each other slightly larger than the distance between the cutting edges of the cutting wheels (4a, 4 b).

Description

Cutter for cutting flat plate or ceramic tile

Technical Field

The present invention relates to a shear for cutting hard tiles or slabs, in particular for cutting and breaking hard cladding material.

Background

As is known, there are many different tools for engraving and cutting slabs or tiles made of ceramic, stone or similar material. The simplest of these is the so-called guillotine, i.e. a tool that can be operated with one hand, which provides two opposite cutting elements that are pressed towards each other by respective advantageous levers hinged together at a central fulcrum axis.

A classical shears is essentially constituted by two parts hinged together, when the cutting element constitutes two opposite shaped ends (typically wedge-shaped or beak-shaped, and having more or less sharp cutting edges) of the respective part.

This simple and inexpensive solution has some drawbacks. First, since the cutting element and the corresponding lever element are integrally formed, they are made of the same material, it is not possible to optimize the performance according to the specific characteristics of each element: the cutting element should have a high stiffness and the lever should have some elasticity and flexural strength. Second, the conventional configuration introduces certain operational limitations. In practice, the cutting element generally has two opposite linear cutting edges arranged orthogonally to the main articulation axis of the guillotine: this is effective in balancing the shears, but hinders the ability to make curved cuts because the space between the cutting edge and the hinge axis is very small and the shears strike the edge of the tile when placed at an angle.

Accordingly, improved shears have been provided on the market, in which the cutting element is constituted by a separate element constrained to the end of the lever by suitable fastening means. In this way, the cutting element may be specifically designed for its use, for example in the form of a wheel of very hard material (cemented tungsten carbide). These wheels also have the advantage of being able to rotate as the cutting edge wears.

An example of a guillotine having such a configuration is illustrated, for example, in figures 3 to 5 of WO 91/17964.

As shown, for example, in design No. 181110-: the cutting wheel is placed on a slightly inclined plane (for example, inclined by 20 °) with respect to the plane of the corresponding lever element. This configuration is more efficient and has better ergonomic effects when the cutting must be performed with a component orthogonal to the edge of the tile (for example when cutting a rectangular or semicircular window along the edge of the tile).

In any case, common to these last solutions is the fact that: the two cutting wheels are arranged in the same plane parallel or slightly inclined with respect to the plane of the lever element of the shears or perpendicular to the fulcrum axis of the lever element of the shears (and so on): this feature serves to prevent the shear wheels from rotating about their point of contact on the tile as a result of the application of a lateral force on the shear body, which would end up applying excessive flexural stress in the plane of the wheels, which would cause them to break (as a hard and brittle material).

This construction limitation means that the maneuverability of the guillotine is not entirely satisfactory when performing a form cut.

The same document WO91/17964 (fig. 1 to 2) describes a guillotine, in which the cutting wheel is arranged on a plane parallel to the fulcrum axis. However, this configuration, in which the wheel is mounted with its central axis on the plane of symmetry of the guillotine, has proved to be not very effective and leaves the wheel in a condition that it is susceptible to breakage under torsional stress.

The applicant has therefore noted that there is room for improvement with such arrangements.

Disclosure of Invention

It is therefore an object of the present invention to provide a manual cutting tool, such as a guillotine, which constitutes an enhancement with respect to the prior art in terms of operability and accessibility of the tool, in particular when performing form cutting.

This object is achieved by the features mentioned in aspect 1. Aspects 2 to 6 describe preferred features of the invention.

1. An engraving shears for ceramic tiles or slabs made of hard material, comprising a pair of lever parts hinged to each other, provided with a handle portion and an end head, respectively, on two opposite sides of the hinge axis, said end heads carrying cutting elements in the form of cutting wheels with peripheral cutting edges, said cutting wheels being fixed in parallel with fastening bosses perpendicular to the lying plane of said pair of lever parts,

said end head being L-shaped so as to define said fastening boss arranged offset with respect to said lying plane; and is

The end heads have opposite projections which, according to the direction connecting the centers of the cutting wheels, extend all the way to a distance from each other which is slightly greater than the distance between the cutting edges of the cutting wheels.

2. The carving shearer of aspect 1, wherein the end head further has a raised protective rib that follows and partially surrounds the cutting edge of the cutting wheel.

3. The carving shearer of aspect 1 or 2, wherein one of the end heads has a pressure surface for applying manual pressure, while the other end head carries a freely rotatable cutting wheel.

4. The carving shearer of aspect 3, wherein the freely rotatable cutter wheel is mounted on a surface of the respective fastening boss by a through screw that engages a counter nut disposed on an opposite side of the surface of the fastening boss.

5. The engraving shearer of any one of the preceding aspects, wherein the pair of lever parts have a closing end stroke holder that determines a closed configuration in which the cutting edges of the cutting wheels are spaced apart by at least 1.5 mm.

6. The carving shearer of aspect 5, wherein the closed end stroke holders take the form of rubber pads mounted opposite one another on the handle portion.

Drawings

In summary, further features and advantages of the invention will become apparent from the following detailed description, given by way of non-limiting example only and illustrated in the accompanying drawings, wherein:

fig. 1, 2 and 3 are front, side and rear views, respectively, of a shear according to the invention;

FIGS. 4 and 5 are top and bottom plan views, respectively, of the clipper of FIG. 1;

FIG. 6A is a perspective view of the shears of FIG. 1, with FIG. 6B representing a partial enlargement;

FIG. 7 is a perspective view similar to FIG. 6A, but on the opposite side;

fig. 8 is a perspective view similar to fig. 6B according to a different line of sight.

Detailed Description

A shear for ceramic tiles or slabs of hard material, such as stone, is constituted, in a manner known per se, by two

lever bodies

1a and 1b reciprocally hinged on a fulcrum or hinge axis 2. The two

lever bodies

1a and 1b have a general S-shape and have, on one side and the other side of the hinge axis 2, longer portions 1a 'and 1 b' serving as gripping ends and shorter portions 1a "and 1 b" serving as pressure heads. This configuration is a configuration that allows to obtain a favourable leverage effect by acting manually on the longer grip portions 1a 'and 1 b'.

Preferably, a spring 3 or other similar elastic element is provided between the two extending portions 1a 'and 1 b' of the lever, which spring 3 or other similar elastic element pushes the two portions apart, thus keeping the guillotine in the open configuration, with the two pressure heads or end heads being further from each other.

According to the invention, each head 1a "and 1 b" of the two levers has an inverted L-shaped configuration (see fig. 2), defining a fastening plane or fastening boss P perpendicular to the lying plane of the

lever bodies

1a and 1b and offset laterally. In other words, as can be clearly seen in fig. 2, the end heads 1a "and 1 b" define a fastening boss having a central axis R which is offset compared to the lying plane of the lever body.

By definition, the central axis R is perpendicular to the boss surface and passes through the center of gravity of the boss surface.

On each of the laterally offset bosses of the two end heads 1a "and 1 b" there is supported a

respective cutting wheel

4a and 4b made of hard material (e.g. cemented tungsten carbide), said cutting

wheels

4a and 4b having a sharp circumferential edge. The circular symmetry axis of the

cutting wheels

4a and 4b is placed substantially on the central axis R of the boss.

The

wheels

4a and 4b are held in place by fastening elements, such as screws 4a 'and 4 b', which are inserted on the central axis R of the boss and thus serve as fastening axes.

Advantageously, the two head ends 1a "and 1 b" have respective

opposite projections

5a and 5b, said

projections

5a and 5b extending below the

wheels

4a and 4b so as to constitute transverse support elements close to the cutting edges of the wheels. The

projections

5a and 5b substantially constitute extensions of the base of the support bosses of the

wheels

4a and 4b, which project from the profile of the end head as short, low-thickness partitions having substantially straight and partially chamfered opposite edges (as can be seen in fig. 6A to 8). The counter-protrusions 5a, 5b extend all the way to a distance from each other that is slightly greater than the mutual distance between the cutting edges of the

wheels

4a and 4 b: in this way they do not interfere with the cutting action (it is believed that the cutting edges of the wheel must be able to penetrate the flat sheet material in more or less significant dimensions depending on the compactness of the flat sheet material), but can be used to apply bending forces to the wheel, as will be explained further below. For example, each protrusion extends up to about 1 to 2mm away from the cutting edge of the respective wheel.

These projections have the dual function of better supporting the

wheels

4a and 4b and of coming into contact with the surface of the slab to be cut (when the longitudinal axis of the tool is inclined with respect to the plane of the slab to be cut) so as to avoid flexural loads acting on the wheels.

The end heads 1a "and 1 b" also have raised

protection ribs

6a and 6b which follow and surround a portion of the circular profile of the

wheels

4a and 4b and extend for a height at least equal to the height of the cutting edge relative to the fastening boss. These

ribs

6a and 6b have the function of preventing accidental impacts of the cutting edges of the

wheels

4a and 4 b: for this purpose, they are arranged on the rear side of the tool, i.e. on the side opposite to the offset direction of the central axis R, i.e. the furthest side from the axis R.

One of the two end heads 1a "and 1 b" also has an enlarged portion defining a pressure surface 7, the pressure surface 7 being arranged at least in correspondence of an axis passing through the centre of the two

wheels

4a and 4 b. The pressure surface 7 is preferably knurled to give it a slip-resistant effect. In case it is desired to perform a sliding cut using the wheel 4b of the tool, the thumb of the user's hand will exert pressure on the pressure surface 7. Thumb pressure is thus directed along an axis passing through the centers of the two wheels and will load the farthest wheel that can carve the surface in contact with it.

For this purpose, the wheel 4b mounted on the end head 1b "opposite to the one on which the pressure surface 7 is formed is preferably mounted freely rotatably on the respective axis R. For example, due to the fact that the support boss is cantilevered with respect to the lever part of the guillotine, a counter nut 8 can be provided on the part projecting below said boss, which engages with the screw 4 b', so as to lock the wheel loosely on its support boss. The free rotation of the wheel 4b makes the pressure engraving action more effective.

Preferably, the raised protection rib 6a located in the vicinity of the pressure surface 7 ends in a sharp corner 6 a' at the intersection with the axis passing through the centres of the two

wheels

4a and 4 b. Since the cutting point of the wheel also falls on this axis, this sharp corner 6 a' can be advantageously used by the user to have a line of sight on the cutting point on the plate that would otherwise be covered by the same tool.

Finally, the tool according to the invention can provide a tilt locking device L hinged on one of the two lever elements 1b, having an operating end suitable for engaging/disengaging the other lever element 1a to determine whether the two lever elements are locked to each other (in the closed position, as shown in fig. 1).

The tool according to the invention can be used in two different modes.

The first method is similar to a conventional guillotine. With the

lever elements

1a and 1b separated in the open position, the plate to be cut is placed between the two opposite cutting edges of the two

wheels

4a and 4b, and then the cutting pressure is applied by manual action on the two

lever elements

1a and 1 b. This pressure is amplified by the lever action and the thin cutting edges of the

wheels

4a and 4b, cutting and breaking the plate. The device is constructed in the following way: even in its fully closed configuration, the two

wheels

4a and 4b are never in contact with each other, but have a clearance between them of, for example, 1 to 1.5 mm: when the plate breaks, the two wheels do not abut against each other, which would cause the two wheels to break. In order to make this operation more comfortable for the user, the stroke closing ends of the two

lever elements

1a and 1b are defined by two

opposite pads

9a and 9b made of a sufficiently soft material (for example, hard rubber) to cushion the impact when determining the breakage of the flat plate to be cut. Two opposing

pads

9a and 9b are mounted on opposing lever portions of the shear, in the vicinity of the spring 3.

In this type of operation, if the user also tilts the tool body with respect to the plane of the plate to take full advantage of the leverage, the two

extensions

5a and 5b come into contact with the surface of the plate, thereby unloading the rotating bends acting on the tool body and avoiding flexural stresses acting on the

frangible wheels

4a and 4 b.

The laterally offset arrangement of the two

wheels

4a and 4b, in which the fastening axis R lying on the cutting plane is offset with respect to the lying plane of the

lever elements

1a and 1b, facilitates the intervention of the user when a form cut has to be made, in particular along a line having a component perpendicular to the edge of the slab to be cut. In fact, the asymmetry of the cutting plane with respect to the plane of the

lever elements

1a and 1b makes it easier to rotate the tool with respect to the plate and to make cuts in the surface starting from the peripheral edge.

The second method is similar to that of a conventional engraving tool. Keeping the tool in the closed position, the user can place the free wheel 4b on the plane of the plate to be cut and roll the wheel 4b on the pressure surface 7 by pressing on this surface, thus producing a surface engraving.

From the above description it can be understood that the tool of the present invention perfectly fulfills the objects set forth in the background.

In fact, the particular configuration of the end head equipped with cantilevered wheels allows the user to easily perform a shaped cut also using the tool as a guillotine. The presence of the projections on the fastening bosses of the wheel prevents the fragile cutting wheel from being subjected to flexural stresses. Finally, the pressure surface opposite the rotating mounting wheel offers the possibility to also use the tool as a surface engraving tool.

It is understood, however, that the invention is not limited to the particular embodiments illustrated above, which represent only non-limiting examples of the scope of the invention, and that various modifications are possible, which are within the ability of a person skilled in the art, without thereby departing from the scope of the invention.

Claims

1. An engraving shear for ceramic tiles or slabs made of hard material, comprising a pair of lever parts (1a, 1b) hinged to each other, provided on two opposite sides of a hinge axis (2) respectively with a handle portion (1a ', 1 b') and an end head (1a ", 1 b") carrying a cutting element in the form of a cutting wheel (4a, 4b) having a peripheral cutting edge, said cutting wheel (4a, 4b) being fixed in parallel with a fastening boss perpendicular to the lying plane of said pair of lever parts (1a, 1b), characterized in that,

said end heads (1a ", 1 b") are L-shaped, defining said fastening boss with a central axis (R) offset with respect to said lying plane; and is

The end heads (1a ', 1 b') have opposite projections (5a, 5b), said projections (5a, 5b) extending in a direction connecting the centers of the cutting wheels (4a, 4b) all the way to a distance from each other slightly larger than the distance between the cutting edges of the cutting wheels (4a, 4 b).

2. The engraving shearer according to claim 1, wherein the end head further has a raised guard rib (6a, 6b) following and partially surrounding the cutting edge of the cutting wheel (4a, 4 b).

3. An engraving shearer according to claim 1 or 2, wherein one of the end heads (1a ") has a pressure surface (7) for applying manual pressure, while the other end head (1 b") carries a freely rotatable cutting wheel (4 b).

4. An engraving shearer according to claim 3, wherein the freely rotatable cutting wheel (4b) is mounted on the surface of the respective fastening boss by a through screw (4b '), which through screw (4 b') engages a counter nut (8) arranged on the opposite side of the surface of the fastening boss.

5. The engraving shearer according to claim 1 or 2, wherein the pair of lever parts (1a, 1b) has a closing end stroke holder (9a, 9b) defining a closed configuration in which the cutting edges of the cutting wheel are spaced apart by at least 1.5 mm.

6. An engraving shearer according to claim 3, wherein said pair of lever parts (1a, 1b) has a closing end stroke holder (9a, 9b) defining a closed configuration in which the cutting edges of the cutting wheel are spaced apart by at least 1.5 mm.

7. The engraving shearer according to claim 4, wherein the pair of lever parts (1a, 1b) has a closing end stroke holder (9a, 9b) defining a closed configuration in which the cutting edges of the cutting wheels are spaced apart by at least 1.5 mm.

8. An engraving shearer according to claim 5, wherein the closing end stroke holders (9a, 9b) take the form of rubber pads mounted opposite each other on the handle portions (1a ', 1 b').

9. An engraving shearer according to claim 6, wherein the closing end stroke holders (9a, 9b) take the form of rubber pads mounted opposite each other on the handle portions (1a ', 1 b').

10. An engraving shearer according to claim 7, wherein the closing end stroke holders (9a, 9b) take the form of rubber pads mounted opposite each other on the handle portions (1a ', 1 b').