US 3778113 A
Rock breaking equipment which utilize a rotor carrying pivoted hammers thereon wherein the axes of the pivots for the hammers are offset from and inclined to the axis of the rotor. The hammer pivots are inclined to the plane at right angles to the axis of the rotor at an angle of 45 degrees and this construction provides a nested assembly of hammers and also the possibility of the hammer striking path lying outside the physical boundaries of the rotor and drive assembly.
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Description (OCR text may contain errors)
States atent [191 1 Dec. 11, 1973 ROCK BREAKING EQUIPMENT [7511 mm B hqrqPTfl lw qhan hvr Transvaal Province, Republic of South Africa I  V Assignee; Angie- Transvaal Consolidated Investment CompanyLimited,
7 Johannesburg, Transvaal, Republic of South Africa M19; 1972  Appl. No.2 230,246
 US. Cl. 299/86, 173/99  Int. Cl. E21c 37/18  Field of Search 299/85, 86, 62
 References Cited UNITED STATES PATENTS 2,680,606 6/1954 Bolton 299/86 X 1,195,396 8/l9l6 Recen 299/86 Primary Examiner-Ernest R. Purser Attorney-Richard K. Stevens et al.
 ABSTRACT Rock breaking equipment which utilize a rotor carrying pivoted hammers thereon wherein the axes of the pivots for the hammers are offset from and inclined to the axis of the rotor. The hammer pivots are inclined to the plane at right angles to the axis of the rotor at an angle of 45 degrees and this construction provides a nested assembly of hammers and also the possibility of the hammer striking path lying outside the physical boundaries of the rotor and drive assembly.
6 Claims, 2 Drawing Figures ROCK BREAKING EQUIPMENT This invention relates to equipment for breaking rock particularly in mining operations.
The rock breaking equipment has been designed into machines where a revolving head supports one or more rotors so that a hole of desired cross-section can be cut into rock. It is also considered desirable that the rotor and hammer assembly be used for cutting narrow slots in rock for, say, stoping in mining operations and it is necessary under such circumstances that the slot cut be wider than the height of the machine.
It is the object of the present invention to provide rock breaking equipment suitable for cutting slots in rock formations.
According to this invention there is provided rock breaking equipment comprising a rotor carrying at least one hammer having a striking tip, the hammer pivotally secured to the rotor at a position offset from the axis of the latter and with the axis of the hammer pivot inclined to the plane at right angles to the axis of the rotor at an angle of more than 45 degrees.
The invention provides further for the rotor to carry a plurality of hammers positioned to follow the same path and/or a plurality of rows of hammers spaced along the length of the rotor.
A simple example of this invention is described below with reference to the accompanying drawings in which:
FIG. 1 is a view along the axis of a rotor according to this invention showing only the top row of hammers; and
FIG. 2 is a view at right angles to that in FIG. 1.
The rotor is of the type generally described in the specification of US. Pat. No. 3,695,724 and need not be detailed here.
The main difference between the construction in the earlier specification referred to and that of the present invention is the attitude of at least some of the hammer pivot axes relative to the rotor.
As indicated, the rotor 1 carries pivotally supported hammers indicated generally at 2 with the axes 3 of the pivots inclined to the plane at right angles to the axis 4 of the rotor. This angle of inclination is to be greater than 45.
The purpose of this arrangement is to enable a greater number of hammers to be mounted on the same plane through the rotor than would be possible with a pivot parallel to the axis of the rotor. The inclination of the axes of the pivots-can be made to result in the striking tips 5 of the hammers 2 operating outside the length of the rotor.
The inherent advantage of a design such as above set out is that, by suitably rebating the rotor, one hammer may be partially nested behind thenext adjacent one'in a row around the rotor. The accompanying drawings indicate this nesting effect'with the body of the particular hammer 6 able to swingback alongside the hammer indicated at 7.
It will, of course, be appreciated that thehammers 2 will be suitably arranged on the rotor l to give as good a dynamic balance to the machine as is practicable. As in our patent application above referred to, each hammer assembly will be designed as a compound pendulum to obtain in use a minimum impact loading on the hammer pivot.
The hammers will also be mounted between resilient end stops controlling the movement of the hammers and the end stops may be hydraulic and also designed to eject cooling fluid to the striking tips.
Each of the hammers according to this invention will be designed to have the desired point of impact at maximum radial extension from the rotor and also, due to the inclination of its pivot axis to the axis of the rotor, this point of impact is located on a plane at right angles to the axis of the rotor and possibly outside of the physical dimensions of the rotor asssernbly as described above.
A further feature of the compact design and tilted hammer axis is that in narrow stopes the angle of strike of the hammers against the footwall or hanging wall can be increased sufficiently to minimize the wear on the sides of the tips.
The increased number of hammers which can be carried by the rotor under the design above set forth as compared with the arrangement where the hammer pivots are parallel to the axis of the rotor will enable an increased number of cutting blows to be effected in a given time. This will, of course, require an adequate power supply but this causes no serious difficulty with modern available motors.
FIG. 2 shows a rotor 1 having two rows of hammers 2 with those hammers 6 being in the swung back and nested positions on the rotor 1.
Each rotor is envisaged as being assembled from a plurality of sub-assemblies each comprising one or more rows of hammers complete with shock absorbers. These sub-assemblies may be made in left-hand and right-hand versions.
By arranging the sub-assemblies on the rotor shaft, any rotor can be converted for use along working faces in a stope which extend to either the left or the right of the equipment.
Also any rotor can be converted to that required to cut along the upper or lower cutting paths down the working face when a pair of rotors are mounted at different elevations and driven to effect, for example, stoping in underground mining operations.
It is possible to manufacture each rotor out of one casting. Left hand and right hand hammers could be used with such castings to obtain different desired effects.
The design results in a compact machine which can be made robust and effective for rock breaking operations under hard rock working conditions.
What I claim as new and desire to secure by Letters Patent is:
1. Rock breaking equipment comprising a rotor carrying at least one hammer having a striking tip, the hammer pivotally secured to the rotor at a position offset from the axis of the latter and with the axis of the hammer pivot inclined to the plane at right angles to the axis'of the rotor at an angle of less than degrees.
2. Rock breaking equipment as claimed in claim 1 in which the rotor has a plurality of hammers similarly mounted thereon and positioned to follow the same path on rotation of the rotor.
3. Rock" breaking equipment as claimed in claim 2 in which there are a plurality of rows of hammers mounted on and spaced apart alongthe length of the rotor.
4. Rock breaking equipment as claimed in claim 3 in which at least the outmost rows of hammers are inclined'as mirror images of each other relative to the plane at right angles to the axis of the rotor.
3,778,113 3 4 5. Rock breaking equipment as claimed in claim 4 in which the rotor is made as a single casting carrying which the rotor is made of two sub-assemblies made as hammers in at least the outer rows thereof which are mirror images of each other and connected axially together.
6. Rock breaking equipment as claimed in claim 4 in 5 mirror images of each other.