As a result of demolition work of old concrete structures, blocks of concrete of different sizes are left over. Crushing machines for concrete blocks are known for bringing the blocks into a smaller space and for separating iron scrap from the inside. In the known crushing machines for concrete blocks there are two superimposed crushing jaws that can be pressed against each other. The compressing surfaces of the crushing jaws include teeth, with the help of which the block to be crushed can be crumbled by pressing the jaws against each other and by grinding. The pressing and grinding is performed by mov- ing the one crushing jaw in relation to the pivoting fastening included in it, generally us- ing some linearly moving actuator, such as a hydraulic cylinder. The movement of the crushing jaws of the present breakers is a sort of static biting movement, in which the block to be crushed is ground to powder and to smaller pieces merely with the help of a large compressive force.

A concrete block is usually crushed by using a strong compression. Large blocks can first be ground by moving the jaws up and down so that, besides compression, also some cut- ting and grinding compression movements are directed to the block. Thus, concrete blocks can usually be crushed with the state-of-the-art machines. However, breaking a strong and big concrete block merely by using compressive movements is relatively slow, because the movements and forces caused by them are mainly compressive, which con- crete endures best, whereas the present breaker hardly generates forces causing tensile stresses, which concrete endures poorly. Because of this, the presently known breakers are relatively slow and require a lot of compression power; further, they are much too massive and large to endure the stresses caused by the high compressive forces.

It is the object of the invention to provide a breaker, with which the above problems can be avoided and with which the concrete blocks to be crushed can be ground into a pulver- ised powder and crumbles in a fast and cost-effective way, using crushing jaws provided with actuators of a lighter structure and requiring lower power than the previous breakers.

Further, it is the object of the invention to bring forth a breaker, the form and amplitude of the path of the crushing jaws of which can be adjusted, and with which it is possible to

break the reinforcements inside the concrete into small pieces using the same breaker without any other tools.

The object of the invention is achieved with a breaker, which is characterised in what is disclosed in the patent claims.

It is characteristic of the breaker of the invention that at least one crushing jaw is pro- vided with a transfer device for moving the crushing jaws reciprocally in relation to each other and for gradually increasing the compressive force with pumping movements during the crushing. Because of the transfer device, the crushing jaws are made to move in rela- tion to each other in the direction perpendicular to the direction of compression. In this case, a cutting force varying in its direction is applied to the block to be crushed in addi- tion to the compressive force so that the block is crushed and ground fast and efficiently, using actuators for the crushing jaws that have a lower power than the merely compres- sive crushing jaws.

In an advantageous embodiment of the invention, the transfer device is an eccentric de- vice. The eccentric device is a simple and inexpensive transfer device, with which the crushing jaws can be made to move in a way efficiently grinding and crushing the block.

Because of the eccentric device, the compressive force of the breaker can further be made enduring and gradually increasing, which increases the crushing efficiency in an advanta- geous way.

At least one crushing jaw is attached to the body through a lever that has been fastened from its middle so that the fastening point of the crushing jaw can be moved by turning the lever. The adjustment of the fastening point makes it possible to adjust the crushing jaws to a preferably horizontal position in relation to the block to be crushed, which makes the operation of the crusher faster and easier.

In a third advantageous embodiment of the invention, the crushing jaw is pivotably at- tached to the one end of the lever, and the breaker includes a linearly moving actuator for turning the lever from its other end. A turning mechanism of the fastening lever of the crushing jaw, executed with a linearly moving actuator, can be made such that it can be kept precisely and reliably in a certain, continuously adjustable position in a simple and inexpensive way.

In a fourth advantageous embodiment of the invention, at least one crushing jaw is pivo- tably attached to the other part from its one end, and the crushing jaw includes a projec- tion, with a linearly moving actuator attached to its free end for turning the crushing jaw.

The rotating device of the crushing jaw realised with a linearly moving actuator is rela- tively strong and easily controllable, and with a simple structure.

In a fifth advantageous embodiment of the invention, the linearly moving actuator is at- tached from its moving end to the free end of the projection of the crushing jaw with the help of an eccentric device so that the length of the grinding reciprocating movement of the crushing jaw is adjustable. Because of the variation in the length of movement and compressive force of the adjustable reciprocating movement thus achieved, it is possible to select for blocks of different sizes and strengths to be crushed the most appropriate and efficient combination of the length of movement and compressive force of the crushing movement so that the breaker can be made efficient and advantageously applicable to many different blocks and materials to be crushed.

In a sixth advantageous embodiment of the invention, the crushing jaws include one or several grooves, mainly extending in the longitudinal direction of the breaker for trans- porting the crushed material away from between the jaws. The longitudinal groove is a simple and inexpensive solution for guiding the crushed and ground material from be- tween the jaws to a desired place, such as under the crusher where some kind of receiver or collection device can be placed for receiving and transporting the crushed material.

In a seventh advantageous embodiment of the invention, the body includes a quick fasten- ing device for fastening the breaker to the front loader of a working machine, such as a wheel-mounted loader. Because of the quick fastening device, the breaker is easily mov- able, because the breaker can be attached in a fast and simple way to the front loader of a working machine, such as a wheel-mounted loader.

In an eighth advantageous embodiment of the invention, the crushing jaws include cutting blades for cutting the concrete reinforcements. Because of the cutting blades, the concrete reinforcements remaining from the crushed concrete, such as reinforcement bars, can be cut into pieces of desired size without separate tools.

The invention is next described in more detail, referring to the enclosed drawings, in which Figure 1 discloses a breaker of the invention, seen from the side; and Figure 2 is a front view of the breaker of Fig. 1.

The breaker in Figures 1 and 2 includes the body 1, the fixed crushing jaw 2, the movable crushing jaw 3, the eccentric device 4 for the movable crushing jaw, the fastening lever 5

for the movable crushing jaw, the rotating device 6 for the fastening lever, the projection 7 of the movable crushing jaw, the rotating device 8 for the movable crushing jaw, the groove 9 of the teeth of the fixed crushing jaw, the quick fastening device 10, the pivoting fastening organ 11 of the fastening lever, the teeth 12 of the fixed crushing jaw, the teeth 13 of the movable crushing jaw, the eccentric device 14 for the rotating device, and the cutting blades 15.

In the embodiment according to Figures 1 and 2, the body 1 and the other structures are welded sheet steel structures. The lower fixed crushing jaw 2 has been formed directly from the sheet structures of the body by incorporating the sharp-pointed teeth 12 manu- factured of steel or other suitable material directly into the upper surface of the jaw, in a way shown in Figure 1. The movable crushing jaw pivotably attached above the fixed crushing jaw with the help of the fastening lever 5 has been manufactured in a respective way, and its lower surface includes the teeth 13 similar to those of the fixed crushing jaw, positioned at the place of the teeth of the fixed crushing jaw in the lateral direction.

The fastening lever 5 for the movable crushing jaw 3 is attached to the body 1 with a ro- tating fastening organ 11. The moving end of the rotating device 6 for the fastening lever is pivotably attached to the projection included in the fastening lever, the fixed end being attached to the body. In the embodiment of Figures 1 and 2, the rotating device is a hy- draulic cylinder. The upper movable crushing jaw 3 is attached to the projection extend- ing outside the body of the fastening lever with the help of the eccentric device 4. The movable crushing jaw is pivotably attached to the eccentric device so that the fastening point for the crushing jaw can be made to move reciprocally along a circular path by ro- tating the eccentric device. The interior of the movable crushing jaw is provided with a hydraulic motor for rotating the eccentric device and with a chain gear from the motor to the eccentric device for rotating it in an appropriate way. The rotating device 8 for the movable crushing jaw is fastened to the third projection of the fastening lever from the fixed end, the rotating device in this case being a hydraulic cylinder. The movable end of the rotating device is pivotably attached to the projection 7 of the movable crushing jaw via the eccentric device 14. By rotating the eccentric device 14, the projection 7 of the movable crushing jaw can be made to move reciprocally along a circular path. For rotat- ing the eccentric device 14, it is connected to the actuator of the eccentric device 4 for the fastening lever via the chain gear. The eccentric wheel included in the eccentric device 14 is adjustably attached in the rotating direction in relation to the rest of the eccentric device so that its phase (phase angle) can be adjusted in relation to the phase of the eccentric wheel of the eccentric device 4. Thus, the form and amplitude of the path of the recipro-

eating movement of the movable crushing jaw achieved by the eccentric devices 4 and 14 can be adjusted to suit different kinds of blocks to be crushed.

In the middle of the teeth 12 of the fixed crushing jaw 2 there is formed a v-shaped groove 9 shown in Figure 2 in order to make the concrete powder generated in the crush- ing to travel below the body in an appropriate way. A suitable receiver can be placed un- der the body for receiving and transporting the powder. The crushing jaws also include cutting blades 15 that are fastened to the end near the fastening lever 5. With them it is possible to cut the reinforcements possibly found inside the concrete into smaller pieces in a desired way. Lugs 10 have been connected to the sheet structure in the other end of the body for fastening the breaker, for example, to the quick fastening device of the front loader of the working machine. Further, hydraulic connections known in themselves (not shown in the Figures 1 and 2) are attached to the body near the quick fastening lugs 10 for connecting the breaker to the hydraulic system of the working machine.

Crushing a concrete block using the breaker according to Figures 1 and 2 is conducted in the following way: 1. The eccentric devices 4 and 14 are adjusted in a suitable way so that a desired phase difference is achieved for the movements of the movable crushing jaw. The magnitude of the phase difference can be used to change the form and amplitude of the path of the grinding movement of the crushing jaws.

2. The eccentric devices 4 and 14 are turned so that the movable crushing jaw 3 is in the horizontal position when it is nearest the body.

3. The fastening lever 5 is turned with the help of the hydraulic cylinder 6 so that the crushing jaws are disengaged in a suitable way.

4. The movable crushing jaw 3 is turned suitably open by using the hydraulic cylinder 8 so that the concrete block to be crushed can be placed between the crushing jaws.

5. The concrete block to be crushed is placed between the crushing jaws, and the crushing jaws are pressed against the block to be crushed with a suitable force using the hydraulic cylinders 6 and 8 so that the surface of the block to be crushed already begins to slightly crumble.

6. The eccentric devices 4 and 14 are started; when rotating, they maintain the prede- termined phase difference. The phase difference can be changed during crushing, if it does not appear suitable after the presetting.

7. As the eccentric devices turn so that the movable crushing jaw begins to move away from the fixed crushing jaw, the movable end of the hydraulic cylinder 8 is moved against this movement so that the compression of the crushing jaws to the block to be crushed remains unaltered.

8. As the eccentric devices turn further forwards so that the crushing jaws begin to again move closer to each other, the movable end of the hydraulic cylinder 8 is kept in place. In this case, the compressive force of the crushing jaws grows clearly bigger than the force which would be achieved by only pressing the hydraulic cylinders. In this case, the crushing of the concrete block will progress fast, because of the strong compression and the movement between the crushing jaws.

9. The pumping crushing movement explained in the above paragraphs will be contin- ued, until the block to be crushed has been ground in a desired way into mostly pulverised form.

10. The possibly remaining reinforcements inside the concrete block can finally be crumbled using the cross cutting machines 13 included in the breaker.

The grinding and crushing movements gradually increasing the compressive force achieved by the eccentric devices in a way explained above can crumble the block to be crushed extremely fast. By changing the phase difference of the eccentric devices in a suitable way, the most appropriate form and amplitude of the pumping crushing move- ments can be found for blocks of different sizes and for blocks that become crushed in different ways. In this embodiment, the phase difference is adjusted manually, as the breaker is at a standstill, by adjusting the position of the eccentric wheel of the eccentric device 14 in relation to the position of the eccentric wheel of the eccentric device 4. The adjustment is carried out by loosening the locking screw of the eccentric wheel, by rotat- ing the eccentric wheel to a desired extent, and by locking the eccentric wheel into its new position. In some other embodiment of the breaker of the invention, the adjustment can also be one that is changed during the use of the breaker or one that automatically seeks the optimal adjustments.

The above embodiment of the breaker of the invention can be implemented in many dif- ferent ways and by using different kinds of equipment solutions. Also the materials for its parts, devices and structures can vary in many different ways. The body and the crushing jaws can be of different sizes and different dimensions. Many different manufacturing techniques and methods can be used in their manufacture. Deviating from the sheet struc-

ture in Figures 1 and 2, they can be made, for example, of some suitably rigid and strong steel pipe by using welding joints and/or other suitable connection methods.

The movement of the crushing jaws can be implemented in many different ways. Instead of one movable crushing jaw, there can be two or several movable crushing jaws. The breaker of Figures 1 and 2 need not necessarily include two eccentric devices both in the place of the movable end of the rotating device and in the place of the rotating fastening for the movable crushing jaw. If the form and amplitude of the path of the grinding movement need not be adjustable, the movable end of the rotating device can in some other embodiment similar to that in Figures 1 and 2 be fastened merely to the projection of the crushing jaw that is moved with the help of a rotating fastening organ. Alterna- tively, the eccentric device in the place of the rotating fastening for the movable crushing jaw can be omitted so that the gradually growing property of the compressive force is generated merely by using the eccentric device included in the movable end of the rotat- ing device, but not the reciprocating movement of the crushing jaw. The eccentric devices included in all the embodiments explained above can also be replaced by some other similar transfer device generating a reciprocating movement and operating mechanically or, for example, hydraulically. However, the eccentric device is preferable, due to its sim- plicity and relatively small need for space.

The actuator for the eccentric device can also be some other actuator besides the hydrau- lic motor. Also different kinds of electric motors, pneumatic motor or combustion engine can be used as the actuator. An electric motor is preferable, if the breaker is to be fixedly attached in place, for example, in connection of a production line. Instead of hydraulic cylinders, motor-driven screws or pneumatic cylinders can be used as actuators. However, the hydraulic cylinder is more preferable than the said known actuators generating a linear movement, due to its simplicity, adjustability and relatively high power yield.

In the different embodiments of the invention, the teeth for the crushing jaws can be manufactured in many different ways. In the embodiment in Figures 1 and 2, they have been made by making the machined steel to endure the loads and wear caused by crushing by machining them and treating them with heat. However, they can also be made in some other way, for example, as a die forge, from a casting or powder-metallurgically. In the embodiment in Figures 1 and 2, the teeth have been fixedly attached to the body, but in some other embodiment, they can also be detachable and changeable. The size of the teeth and the distance between the teeth in case of teeth made for crushing different mate- rials can vary.

The breaker of the invention can be used for crushing many different materials intended to be broken by crushing. Besides concrete, the breaker can be used for crushing, for ex- ample, different stones, clay, bricks, gypsum and many other brittle ceramic materials.

The size of the block to be crushed can vary. Several blocks can be crushed simultane- ously, and feeding the blocks to the breaker can be arranged continuously, for example, with the help of a belt conveyor, or the blocks can be fed one by one. The breaker can in- clude fastening lugs suitable for the quick fastening device according to Figures 1 and 2, or the breaker can be attached fixedly in place. In case of the quick fastening device, dif- ferent working machines can be used for moving the breaker, such as a wheel-mounted loader or a tractor provided with a front loader.

The invention is not limited to the advantageous embodiments shown, but it can vary within the inventional idea formed by the patent claims.