CA1092826A - Vibration barrel grinding device - Google Patents

Abstract

VIBRATION BARREL GRINDING DEVICE
Abstract of the Disclosure:
A vibration barrel grinding device, particularly for use with light articles, has an outer peripheral wall of the barrel forming a toroidal-shaped tub. Such peripheral wall extends up to an abruptly inwardly extending wall portion to force the grinding mass inwardly. A cylindrical core is mounted, either fixed or rotatably, to form the inner peripheral wall of the barrel and a number of blades are provided on the core, these blades being inclined downward so that the flow of the grinding mass is forcibly moved downwards to improve the grinding efficiency.

Description

~0~28~6 The present invention relates to vibration barrel grinding devices and more particularly to a vibration barrel grinding device adapted to grind light articles.
To enable the prior art to be described with the aid of drawings, the figures of the accompanying drawings will first be described.
Fig. 1 is a vertically sectioned elevation of a conventional vibration barrel grinding device.
Fig. 2 is a plan view of Fig. 1.
Fig. 3 is a partly sectioned elevation showing an embodiment of a vibration barrel grinding device of the present invention.
Fig. 4 is a plan view of Fig. 3.
In a conventional toroidal-shaped vibration barrel grinding device, as shown in Fig. 1, a mass contained in a doughnut-shaped barrel tub 1 resonates with a forcible rotary vibration given to the arcuate bottom wall la of the barrel tub 1 so as to be forcibly made to rise as indicated by the arrow a toward the outer peripheral wall lb from the arcuate bottom wall la. The thus elevated mass flows as indicated by the arrow b in the drawing toward the inner peripheral wall lc of the barrel tub 1 and rotates while flowing to the arcuate bottom wall la of the barrel tub 1.
Such rotary motion of the mass in the barrel tub is given by rotating an upper weight 3a and bottom weight 3b fitted to both ends of a motor 2 so as to strongly vibrate the barrel tub 1 mounted on springs 5 on a mount 4.
Therefore, the strong vibration given to the barrel tub 1 will be transmitted to the mass within the barrel tub and will forcibly rotate the mass so as to generate a mutual r~
~ - 1 -: ,;~ .!

~092826 motion having a mutual contact pressure between a grinding material and a workpiece in the mass to grind the work-piece. If the respective weights 3a and 3b fixed to the shaft of the motor 2 are made to have an advance angle, the mass will rotate and flow in the direction indicated by the arrow c in the barrel tub while spirally rotating as indicated by the solid line arrow in Fig. 2 so as to grind the workpiece or workpieces.
However, there have been problems. If the workpiece to be ground is a comparatively light article, when it is caused to rise as indicated by the arrow a toward the outer peripheral wall lb of the barrel tub 1 and flow toward the inner peripheral wall lc, it will rise up out of the grinding material. So long as it is not submerged in the grinding material, it will not be ground and this will reduce the grinding efficiency.
An object of the present invention is to provide a vibration barrel grinding device wherein the above mentioned problem is eliminated or minimised, even light articles being effectively ground.
To this end the invention provides the improvement in a vibration barrel grinding device having a toroidal-shaped grinding tub in which vibrating means effects a rotary flow pattern of a mass within the tub about the toroidal tub while spirally rotating along that rotary flow pattern, comprising the provision in the center of the grinding tub of blade structure having at least one projecting blade inclined downwardly along the toroidal tub wall and inclined in the rotary flow direction of the mass to forcibly submerge and direct the mass downwardly at the center of the toroid and upwardly against the outer

- 2 -lO9Z826 toroidal tub wall to provide a rotary and spiral movement force supplemental to that imparted by said vibration and thus more efficiently grind work materials particularly light weight materials.
Detailed Description of the Preferred Embodiment:
Fig. 3 is a partly sectioned elevation showing an embodiment of a grinding device of the present invention.
Fig. 4 is a plan view or the same. The same reference numerals are attached to the same parts as in Figs. 1 and 2. In the drawings, the outer peripheral wall of a barrel tub has a wall ld that extends abruptly inwardly above the substantially vertically extending wall lb to exert a pressure on the upwardly flowing mass. Arrow d indicates the diverted direction of grinding flow and e indicates the subsequent flow direction of grinding caused by the pressure. As a result of the inwardly extending wall ld, the grinding flow will be forced in the direction indicated by the arrow d. A strong friction flow will be produced by this action and a strong grinding will be obtained.
As distinct from the flow in Fig. 1 of the conventional method, as shown in Fig. 3 of the embodiment of the present invention, the flow will rise to a high position at the upper surface of the tub and will then rotate and flow to a high location on the wall lc. As a result, the grinding will be effective and efficient. Numeral 6 is a cylindri-cal core rotatably mounted on the inner peripheral wall lc of the device. An appropriate number of blades 7 are inclined downward of the peripheral surface of this cylindrical core. The direction of inclination is the rotating and flowing direction lindicated by the arrow c in Fig. 4) of the mass. The cylindrical core 6 may be ~ _ 3 _ :.~-, : .,,, : .

~O~Z826 rotated by a motor 2 provided in the center space of the barrel tub 1 or by any different method.
In such apparatus, if the mass is rotating and flowing in the direction indicated by the arrow c in the barrel tub 1 while spirally rotating as indicated by the solid line arrow as shown in Fig. 4, the cylindrical core 6 will be rotated either in the reverse direction or the same direction as desired. Then, due to the inclined surfaces of the blades 7 of this cylindrical core 6, a pressure will act in the direction of pushing the grinding material and the work to be ground, and therefore any work that has floated up will again be submerged into the grinding material due to the blades 7, and will be forcibly made to rise towards the outer peripheral wall lb from the arcuate bottom wall la so as to be ground. The contour and inclination angle of the blades 7 can be freely selected as found most effective. Further, it is not essential to rotate the cylindrical core. Even if the core is stationary, the mass will move along the inclined surfaces of the blades 7 and therefore the work to be ground will be submerged into the mass.

3~
... . .. .

Claims (3)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The improvement in a vibration barrel grinding device having a toroidal-shaped grinding tub in which vibrating means effects a rotary flow pattern of a mass within the tub about the toroidal tub while spirally rotating along that rotary flow pattern, comprising the provision in the center of the grinding tub of blade structure having at least one projecting blade inclined downwardly along the toroidal tub wall and inclined in the rotary flow direction of the mass to forcibly submerge and direct the mass downwardly at the center of the toroid and upwardly against the outer toroidal tub wall to provide a rotary and spiral movement force supplemental to that imparted by said vibration and thus more efficiently grind work materials particularly light weight materials.

2. The improvement defined in claim 1 wherein the blade structure comprises a set of blades positioned on a core member relatively movable to the toroidal tub.

3. The improvement defined in claim 1 or 2 wherein the toroidal tub has from its outer periphery an abruptly inwardly extending wall portion exerting a pressure upon the upwardly flowing mass.