US 2124983 A
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Description (OCR text may contain errors)
Patented July 26, 1938 UNITED STATES PATENT OFFICE AGITATOB Joseph Martim'San Francisco, Calif. Application August 30, 1937, Serial No. 161,555
This invention relates to improvements in agitators and more particularly to agitators for gravitational'ore concentrating jigs.
Among the objects of this invention is to provide means for varying the amplitude of the agitation within wide limits to accord with the character of the material being concentrated. The. larger the particles and the greater their specific gravity, the more vigorous is the agitatioh required for eflicient concentration. In the case of finely ground materials, too vigorous agitation will impede the descent of the finely divided values. I
Another object is to provide mic'rometric regulating means so that the agitation may be accuit is capable of a wide range of applications; for
example, the gravitational grading of grain by agitation.
In this specification and the accompanying drawing the invention is disclosed in its preferred form. It is, however, to be understood that it is not limited to this form because it may be embodied in other forms within the purview of the claim following the description.
In the one sheet of drawings:
Fig. 1' is a vertical section diagrammatically illustrating an agitator constructed in accordance with the present invention applied to a conventional gravitational ore concentrating jig.
Fig. 2 is a similar view showing the actuating means. for the agitator.
In detail, the construction illustrated in the drawing, referring more particularly to Fig. 1, comprises a conventional ore concentrating jig constructed in the usual manner and consisting of boiler plate or similar material. It has the sides i and 2 and the sloping bottom 3. The fitting 4 is welded to the lowest point of the bottom 3 around the opening 5 therein. The
threaded plug 6 closes the fitting 4 and is periodically removed for the withdrawal of accumulation of concentrated values.
The horizontally disposed wire screen I is supported on the transverse struts 8 near the top of the jig. The mesh of the screen 1 will depend upon the size of the particles of the material being concentrated. A water suspension of the material to be concentrated flows down the chute 9 on to the screen 'i in the jig. Riilles and other refinements common in this art may be frovided where desired. The collar I0 welded o: the side wall I near its lower end has the water supply pipe Ii screwed therein. This enables the introduction of clean water into the jig in accordance with usual procedure.
The structure thus far described is a conventional concentrating jig. The invention is equally adaptableto other types and forms of jigs which are common in this art.
The cylindrical spacer i2 is bolted to the side wall I surrounding the opening i 3 therein. The chamber it is secured to the spacer H by the bolts i5. .The flexible diaphragm it has its margins confined between the abutting flanges of the spacer i2 and the chamber M. Buckling of the diaphragm i6 is prevented by the disc ll which is secured to the diaphragm l6 by the stem it having the retaining nut ill. The disc II is preferably of stifi leather as indicated. Other material may be employed if desired.
The stem it extends laterally from the diaphragm i6 and is encircled by the helical spring l9. The hollow tension regulator is threaded in the fitting 2! which is bolted to the chamber M. It telescopes over and guides the stem l8 and bears against the spring ill. The spring l9 expanding between the regulator Zll and the disc ll urges the diaphragm it outward from the chamber M. The outer end of the regulator 20 is provided with the hexagon 22 to receive a suitable wrench for adjustment of the regulator 20 so that the tension of the spring i9 may be varied, for purposes later to be described. The lock nut 23 is arranged to hold the regulator 20 against rotation so as to maintain the adjustment thereof.
The fitting 2i has the nipple 24 having the heavy non-collapsible hose 25 telescoped thereover. The opposite end of this hose 25 has the nipple 26 telescoped therein which projects from the chamber 21. This chamber 2! is closed by the diaphragm 28 which has its margins confined between the marginal flange of the chamber 21 and the ring 29 bolted thereto. The disc 30 prevents buckling of the diaphragm 28 and is secured thereto by the stem 3| and the nut 32. The lower end of the stem 3| is bolted to the plunger 33 which is slidable within the guide 36 joined to the ring 29 by the spider 35. The plunger 33 is connected to the crank pin 36 of the crank shaft 31 by the pitman 3B. The crank shaft 31 is journalled in the standard 39 which supports the guide 4. Suitable means, not shown, are provided for driving the crank shaft 31.
'The invention operates substantially as follows: The crank shaft 36 is driven at a speed which depends upon the frequency of the agitation desired in the jig. The rotation of the crank shaft reciprocates the plunger 33, whichmotion is transmitted to the diaphragm 28 by the stem 3|. This rhythmically reduces the pressure in the chamber 21. The hose 25 transmits the pulsating pressure through the fitting H to the chamber M. The diaphragm l6 responds to the pulsating pressure reduction in the chamber M by contracting against the tension of the spring l9. This sympathetic vibration of the diaphragm l6 agitates and churns the water in the adjoining concentrating jig. The heavier particles settle toward the bottom through the screen 'I while the agitation maintains the lighter particles in suspension. The practical technique oi the concentration forms no part of the present invention and is carried out in the well known manner which is described in detail in any standard text book relating to the subject.
The amplitude of the agitation desirable depends upon the size of the particles in suspension. Increasing the thrust of the spring [9 by adjustment of the regulator 20 limits the travel of the diaphragm l6 when the pressure in the chamber I4 is reduced by the operation ofthe diaphra'gm 28. The tension 01; the spring l9 can be increased until it approaches the hydrostatic head plus atmospheric pressure on the opposite side of the diaphragm Hi. The amplitude of the vibration of the diaphragm will then be negligible. Conversely, the thrust of the spring is may be relieved until the diaphragm l6 respon'ds freely to the pressure variation thus providing a maximum vibration amplitude which depends upon the travel of the actuating diaphragm 2B and the relative sizes of the two .diaphragms.
' It will be obvious to; thoseskilled in the art that, by suitably increasing the dimensions 0! the actuating diaphragm 28, a plurality of agitators diaphragms such as I6 may be operated therefrom.
It will be noted that, apart from the actuating unit, the operative stresses are confined to the diaphragm I6 and. the chamber l4, thus relieving the body of the concentrating jig from destructive strains and excessive vibration.
Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:
An agitator for gravitational ore concentrating jigs comprising a chamber; a diaphragm closing said chamber and in operative relation to the mass to be agitated; means for providing a pulsating pressure in said chamber to reciprocate said diaphragm; a stem attached to said diaphragm and extending across said chamber; a hollow regulating member threaded in said chamber and arranged to telescope over the free end of said stem; and. a spring interposed between said regulating member and said diaphragm and encircling said stem.