The present invention relates to a device for cutting and crushing hard materials, in particular a shear-type device for cutting reinforcement bars and crushing concrete.

The state of the art discloses shears for cutting reinforcement bars and crushing concrete, comprising a base on which a housing is mounted with its one end. Cutting arms are pivotally attached to a second end of the housing. At one of its ends, each of the arms is connected to an actuating member, such as a servomotor, and at a second opposite end the arms have cutting attachments. Lengthening or shortening of the actuating member causes the cutting arms to rotate at the point of their pivot connection to the housing and as a result the reinforcement bars are cut and the concrete is crushed.

In known solutions, when cutting and/or crushing hard materials, such as reinforcement bars and concrete, very heavy loads are transferred from the cutting arms to the housing via the pivot connection between these elements. This causes continuous deformation or even destruction of the housing at the point of its connection to the cutting arms. Over time, at the point of connection of the cutting arms to the housing, play or even cracks appear, which prevent the shears from functioning effectively. It is then necessary to replace the entire housing with a new one.

Moreover, the costs of making such a housing are high. Due to the necessity to transfer significant forces by the housing, many processing steps are necessary, such as milling, bending elements of different thickness, etc. In the event of damage to the housing, manufacturers usually recommend replacing the entire housing, which additionally affects the high costs of such an operation.

One aim of the present invention is to provide a device for cutting and crushing hard materials, which would allow the replacement of individual parts of the device in a quick, simple and relatively cheap manner.

Another aim of the present invention is to provide a device for cutting and crushing hard materials that is stronger at the point of pivot connection of the housing to the cutting arms. A device for cutting and crushing hard materials comprises a base; a housing mounted with its first end on the base; a pair of cutting arms pivotally connected to a second end of the housing opposite the first end of the housing; and an actuating member pivotally connected to first ends of the cutting arms; the device according to the invention is characterized in that two intermediary bands are located at the point of pivot connection of the cutting arms to the housing and between the cutting arms and the second end of the housing, one intermediary band on each of two sides of the cutting arms, the intermediary bands being separate elements from other elements of the device.

Preferably, the housing is one unitary piece.

Preferably, the housing comprises two separate halves.

Preferably, the housing is made of bent sheet metal.

Preferably, the actuating member is a hydraulic actuator.

Preferably, the base comprises a base plate on which the housing is mounted, a rotator mounted on the base plate and an adapter for connecting the device to components of a machine for controlling the operation of the device.

Preferably, the pivot connection of the cutting arms to the housing comprises bushings inserted into openings of the cutting arms and bolts and nuts, screwed together, passing through corresponding openings in the intermediary bands and openings in the housing.

In the present invention, loads from the cutting arms are not transmitted directly to the housing. Due to the use of the intermediary bands, which are separate elements from other elements of the device, in particular the cutting arms and the housing, most of the loads will be concentrated on the intermediary bands themselves. As a result, mainly the intermediary bands will wear and/or deform. In the event of excessive wear of the intermediary bands and the resulting play in the cutting arms, only these intermediary bands have to be replaced. The intermediary bands can be replaced quickly and easily.

In the case of the device according to the present invention, the production costs are lower and the thickness of the intermediary band can be easily varied in the event that we wish to obtain greater strength of the device without changing the entire housings. In addition, bending of the housing is easy due to the fact that the thickness of the housing can be the same over its entire surface. A great advantage of this solution is also the possibility of using intermediary bands made of a material other than the housing, for example the intermediary bands can be made of non- weldable steel, can be hardened, etc.

The subject matter of the present invention is illustrated in its embodiments in the drawings, in which Fig. 1 shows a perspective view of a device for cutting and crushing hard materials, in an assembled state, and Fig. 2 shows an exploded view of the device.

A device 1 for cutting and crushing hard materials, in particular concrete and reinforcement bars, comprises a base 2. The base 2 is a subassembly on which remaining elements of the device 1 are mounted and which is connected on the other side to a machine/device (not shown) for controlling the operation of the device 1 and supporting the device 1.

In the embodiment shown in the figures, the base 2 comprises a base plate 21 on which a rotator/a rotating unit 22 is mounted, and an adapter/an intermediary element 23 is mounted on the rotator 22. The components of the base 2 can be connected to each other by various connecting means, for example bolts with a nut and a washer.

The task of the rotator 22 and the adapter 23 is, respectively, to rotate the device 1 relative to the machine for controlling the operation of the device 1 and to connect the device 1 to the machine for controlling the operation of the device 1 (e.g. by means of a supporting arm, etc.).

However, in other embodiments of the present invention, not shown in the figures, the base 2 may take a different form. For example, the base plate 21, the rotator 22 and the adapter 23 can be integrated uniformly into one unit. Moreover, the base 2 may be devoid of some elements, for example the rotator 22, and the function of a missing element is performed by further elements of the machine for controlling the operation of the device 1.

The device 1 further comprises a housing 3 which is, at its first end, mounted on or connected to the base 2, and in particular, in the embodiment of the invention shown in the figures, to the base plate 21 of the base 2. In the embodiment shown, the housing 3 is in the form of two separate halves of the housing 3, which are connected at their first end to the base 2, in particular to the base plate 21. At their second end opposite the first end, the halves of the housing 3 have openings 31, which are used to pivotally fasten a pair of cutting arms 4, as described in detail below. In another embodiment of the invention, not shown in the figures, the housing 3 is one unitary piece and is mounted with its first end on the base 2, in particular on the base plate 21, and at its second end opposite the first end the housing 3 likewise has the openings 31, which are used to pivotally fasten the cutting arms 4.

The housing 3 can be made of, for example, bent sheet metal.

In the embodiment of the invention shown in the figures, the housing 3 embraces the cutting arms 4.

The device 1 further comprises a pair of the cutting arms 4. The cutting arms 4 are connected at their first ends by an actuating member 5. The connection between the cutting arms 4, and in particular their first ends, and the actuating element 5 is pivotable, i.e. it allows the cutting arms 4 to rotate with respect to the actuating member 5 and, consequently, other elements of the device 1. Such a pivotal connection can be achieved, for example, by means of bushings inserted into the first ends of the cutting arms 4 and into ends of the actuating member 5. Bolts are in turn inserted into the bushings, which bolts are fixed in place by means of nuts.

At their second ends, opposite the first ends connected to the actuating member 5, the cutting arms 4 have cutting attachments 42, which cut and/or crush the processed material. The cutting attachments 42 may be replaceable elements secured to the cutting arms 4 by means of bolts. However, in another embodiment of the invention not shown in the figures, depending on the application, the cutting arms 4 do not need to have cutting attachments 42. In this case, the cutting arms 4 are hard enough to themselves be able to crush and/or cut the given material.

The actuating member 5 may be a hydraulic, electric or pneumatic actuator, depending on the needs and the specific application. If necessary, there can be provided an additional hydraulic amplifier 12, the so-called booster, connected by pipes to the actuating member 5 and to other elements of the machine for controlling the operation of the device 1. The hydraulic booster 12 "boosts" the pressure and guarantees the pulsating operation of the cutting arms 4. For example, the hydraulic booster 12 allows to obtain 500 bar at the pressure of 165 bar supplied to the cutting arms 4.

The cutting arms 4 are pivotally connected to the second end of the housing 3, which is opposite the first end of the housing 3 mounted on the base 2. To this end, between the first end attached to actuating member 5 and the second end provided with cutting attachments 42 or intended to cut a material, each cutting arm 4 has an opening 41, which serves to pivotally connect the cutting arms 4 to the housing 3 of the device 1. The openings 41 are aligned with the openings 31 in the housing 3. Bushings 8 are inserted at least into the openings 41 of the cutting arms 4. Bolts 9 and nuts 10, screwed together, are in turn inserted into the bushings 8 and pass through corresponding openings 71 in the intermediary bands 7, described in detail below, and the corresponding openings 31 in the housing 3. The bolts 9 and the nuts 10 somehow embrace and rotatably connect, by means of their respective flanges and/or heads, the cutting arms 4, base washers 10, the intermediary bands 7 and the housing 3 with each other. The bolts 9 may, for example, have an internally threaded hole for receiving an externally threaded shank of the nut 10 - obviously, a reversed thread pattern is also possible.

However, in other embodiments of the present invention, not shown in the figures, the pivot connection between the cutting arms 4 and the housing 3 may be carried out in a different way. For example, in some applications it is not necessary to use the bushings 8, the bolts 9 and the nuts 10 will suffice.

In general, the lengthening of the actuating member 5 causes the cutting arms 4 to rotate about the point of their pivot connection to the housing 3, in particular on the bushings 8/the bolts 9, and brings the second ends/the cutting attachments 42 of the cutting arms 4 closer to each other. Conversely, the shortening of the actuating member 5 causes the cutting arms 4 to rotate about the point of their pivot connection to the housing 3 in the opposite direction and moves the second ends/the cutting attachments 42 of the cutting arms 4 apart. The synchronous movement of the cutting arms 4 relative to each other is achieved by the use of a lock 11 in the vicinity of the openings 41 of the cutting arms 4. The lock 11 comprises a recess on one cutting arm 4 and a corresponding projection on the other cutting arm 4. The projection is placed in the recess, what forces the cutting arms to rotate synchronously while lengthening and shortening the actuating member 5.

The device 1 also has two intermediary bands 7, one intermediary band 7 on each of two sides of the cutting arms 4, which sides face the second end of the housing 3, in particular in case of the housing 3 embracing the cutting arms 4 these two sides of the cutting arms 4 are directed towards two parts of the housing 3 on which parts the cutting arms 4 are mounted. The intermediary bands 7 are arranged at the point of pivot connection of the cutting arms 4 to the housing 3, i.e. in the embodiment of the invention shown in the figures between the cutting arms 4 and the second end of the housing 3. The intermediary bands 7 are separate elements from other elements of the device 1, in particular the cutting arms 4 and the housing 3. Each intermediary band 7 has two openings 71, aligned with the openings 41 of the cutting arms 4 and the openings 31 of the housing 3. The bolts 9 and if necessary the nuts 10 pass through the openings 71 of the intermediary bands 7 to allow for pivot connection of the cutting arms 4 to the housing 3.

Due to the use of the intermediary bands 7 most of the loads coming from the cutting arms 4 when cutting or crushing a given material are concentrated on the intermediary bands 7 and not on other sensitive elements of the device 1, such as the housing 3. As a result, mainly the intermediary bands 7 are subject to wear. As the intermediary bands 7 are separate elements from other elements of the device 1, their replacement is quick, simple and cheap, and the intermediary bands 7 themselves can be made of a material other than the housing and can be non-weldable, hardened, etc.

Moreover, the intermediary band 7 itself serves to ensure that when the actuating member 5 is lengthened and shortened, the cutting arms 4 in their lower part do not diverge laterally. On the other hand, during the crushing and cutting of the processed material (such as concrete and reinforcement bars), the cutting arms 4 are not allowed to move in a plane perpendicular to the movement of the actuating member 5.

The device 1 may also have two base washers 10 with openings 101, preferably made of copper, bronze, brass or PA6 polyamide, placed between the cutting arms 4 and the intermediary bands 7. The base washers 10 serve to separate the cutting arms 4 from the intermediary bands 7, whereby any possible friction that may result from the movement of the cutting arms 4 is transferred to the base washer 10 and not directly to the intermediary bands 7.