The present invention relates to a jaw crusher, particularly a stone crusher, comprising two crushing plates, one inoperative, stationary, preferably adjustable crushing plate and one opposing, operative, movable, eccentrically driven crushing plate.

In known jaw crushers of this kind, the operative crushing plate is usually on the upper or lower part pivotally mounted about a stationary axis, wherein the end portion of the crushing plate located opposite the mounting thereof constitutes the movable, crushing part of the plate. Such a mounting involves that the operative crushing plate must be given a large movement or stroke at said crushing part in order to obtain a certain movement adjacent the mounted end. Such a large stroke involves increased crusher dimensions within the plane for the pivotal movement of the operative crushing plate.

Moreover, in known jaw crushers of this kind, said mounting involves an inappropriate crushing and other treatment, including transport towards the outlet opening, of stones and other materials which are desired to be crushed to pieces having less and more usable sizes.

Therefore, in accordance with the present invention, one has aimed at eliminating or substantially reducing these deficiencies and disadvantages of prior art technique and,

thus, at providing a jaw crusher wherein the stroke of the operative crushing plate is reduced in relation to known jaw crushers, and wherein crushing and associated treatment of the material to be crushed, including the suitable transport thereof towards the outlet opening, are improved in relation to prior art technique.

According to the invention, this object has been realized in that a jaw crusher of the kind defined introductorily, has been designed in accordance with the features appearing from the following claims.

In accordance with the invention, the operative, movable crushing plate is mounted on two εpacedly disposed, rotary, operatable shaft portions, each eccentrically positioned in relation to the respective drive axis belonging thereto; i.e. the shaft portions to be mounted and driven are the centrical shaft portions of the respective shaft in which each of the eccentrical shaft portions is included. Thus, said drive axis coincides with the rotational axis of said centrical shaft portions.

The two shafts are synchronized.

The defined mounting device for the operative crushing plate allows that the entire crushing plate, from top to bottom, is given an equal movement and an equal stroke.

As the operative crushing plate is mounted on said two eccentrical shaft portions, and wherein synchronized shafts are used, homogenous crushing effect is achieved across the operative movable crushing plate. Therefore, the stroke thereof may be reduced in relation to prior art technique, resulting in smoother operation and performance, larger revolution, lower need for power, as well as improved crushing economy. With such a mounting, the operative crushing plate will obtain a crushing movement as well as a rotating movement.

During the rotation of the two eccentrical shaft portions, over approximate 90 degrees rotational intervals, (I) firstly, a crushing and pressing-down of the masses worked take place; (II) thereafter the masses partially get the opportunity of falling and being drawn downwardly towards the outlet opening; (III) whereafter the masses get further possibilities of "working" their way downwardly; and (IV) finally, the masses become turned to and fro, up and down, so that a better contact with the crushing plates is attained, under which movements compression of the masses takes place and the crushing starts.

An example of a preferred embodiment is further explained in the following, reference being made to the accompanying diagrammatical drawings, wherein:

Figure 1 shows a side elevational view of a jaw crusher of the invention, partly in section on line I - I in figure 2;

Figure 2 shows a top plan view of the jaw crusher of figure i;

Figure 3 shows diagrammatically a gear transmission for synchronous operation of the shafts wherein the aforesaid eccentrical shaft portions are included, forming the mounting of the operative crushing plate.

In the drawings, such well known constructive details as lubricating system, bearings, the pitch of gear, etc., have been omitted.

The housing of the jaw crusher shown is designed as an external box having two mutually opposing solid side walls 1 and two mutually opposing, partly open end walls 2, wherein side and end walls 1, 2 are welded together to form a sturdy, braced unit.

Within the box, two crushing plates 3 and 4 are disposed.

One crushing plate 3 constituting the inoperative, stationary crushing plate of the jaw crusher, is on the upper part, for adjusting purposes, pivotally mounted on a stationary shaft 5, whereby the inclination angle of the crushing plate 3 may be adjusted in relation to a vertical plane, in order to adjust the outlet opening 6 to the desired slot measure and, thus, the fed-out stone size. For the adjustment of the inoperative crushing plate 3 serves an adjusting means 7 built up from a number of shims or spacers 7 ' and disposed at the bottom end of the crushing plate 3. The inclination angle of the inoperative crushing plate 3 is altered upon removal or addition of one or more of said shims or spacers 7 ' . Subsequent to adjustment, the crushing plate 3 is locked in position by means of bolts 8.

The other crushing plate 4 constituting the operative, movable crushing plate of the jaw crusher, is mounted on two equal eccentrical shaft portions 9 and 10 by means of slide bearings, the two eccentrical shaft portions 9 and 10 being located at different levels.

The centrical shaft portions of the shafts each including one of the eccentrical shaft portions 9 and 10, respectively, is denoted 11 and 12, respectively. The centrical rotational axis of the shafts is denoted 11' and 12*, respectively, the axes of the eccentrical shaft portions 9, 10 being indicated at 9 ^• , 10'.

At the end portions, the centrical portions 11 and 12 of the shafts are passed through the external box, on which they are mounted in slide bearings 13 and 14, see figure 2.

At one side wall 1 of the box 1,2, the centrical shaft portions 11, 12 are passed into a gear housing 15; here, each centrical shaft portions 11, 12 is provided with a gear wheel 16 and 17, respectively, see figure 3.

In relation to the eccentricity of the shaft portions 9 and

10, these gear wheels 16, 17 are disposed synchronously meshing with a drive gear 18 mounted on a shaft 19. This shaft 19 is mounted in bearings and carries a fly wheel 20.

The mounting of the operative movable crushing plate 4 on the two eccentrical shaft portions 9 and 10 allows the entire crushing plate 4, from top to bottom, to get an equal movement and an equal stroke.

As the operative movable crushing plate 4 is mounted on the two eccentrical and synchronized shaft portions 9 and 10, a uniform crushing effect across the entire crushing plate 4 is achieved, allowing the stroke to be reduced. Again, this involves a smoother running to be obtained, simultaneously as the rotational speed may be increased. Additionally, a better crushing economy is achieved, i.a. due to a decreased power need.

The operative movable crushing plate 4 will get both a crushing and a rotating motion.

In figure 1, the shaft cross sections of the shafts 9, 11 and 10, 12 are divided into 90° intervalls a - d:

Upon rotation of the eccentrical shaft portions 9 and 10 from a to b, a crushing and pressing-down of the masses will occur; from b to c a partial opening in the downward direction will occur, so that the masses may partly fall and partly be drawn downwardly; from c to d a further opening will occur, so that the masses get increased possibilities to "work" themselves downwardly; and from d to a the masses will be turned to and fro, up and down, so that a better contact between the material to be crushed and the plates 3, 4 is obtained. In this condition, compression of the masses occurs, and crushing starts.