IL27572A - Apparatus for finishing small articles - Google Patents

Description

C O H E N Z E D E & S P I S B A C H REGD. PATENT ATTORNEYS 24, LEVONTIN SIR., P. O. B.1169 I E L · A V I V P A T E N T S & D E S I G N S O R D I N A N C E 16318/67 SPECIFICATION FINISHING APPARATUS i?QK ¾^SiW SiaALL.AriTlCLE'S o¾i¾p Ο*Τ.ΜΒ m'a> 7 j? n n . HANS OFTIKE'R, a Swiss citizen, of , Oberdoxf stiasse , Horgen, Switzerland, HEREBY DECLARE ihe nature of this invention and in what manner the same is to be performed to be particularly described and ascertained in and by the following statement : The present invention relates to an apparatus employing rotating drums for treating small articles.

Usually in such apparatus the rotating drum is tiltable. For filling in the articles to be treated and for their emptying the drums the latter can be tilted with i-fce opening downwardly or upwardl .

It is an inherent drawback of such apparatus that the treatment therein takes considerable time. According to the size of the articles to be treated such a treatment may last many hours. It has been found that the result of the treatment, i.e. the obtained polish or cleaning effect of the articles, is dependent to a large degree on the mutually acting forces exerted by the individual articles onto each other and also from the added grinding or polishing material. Heavy articles exert greater rubbing and frictional action on each other, than lightweight articles.

The forces acting mutually between the said small articles can be increased thereby that in addition to the rotative movement of the drum about its axis, an additional movement along a circular path is imparted to it so that the articles are subject to an additional acceleration, which results therein that the mutually acting forces are increased manifold as compared xfith a drum which rotates about a fixed axis. There are known apparatus of this kind wherein the rotating drum is arranged on an horizontal shaft and wherein the individual drums perform circular motion along a cylindrical plane. Such drums are provided with bearings at both ends of the shafts. The opening for filling and The lid for the opening has to be of a tightly fitting kind and practically must provide hermetical closure. This is due to the fact that liquids which are filled into such drums for cleaning or polishing purposes have a tendency of escaping through every possible opening. All the said drawbacks are eliminated by construction according to the present invention.

The present invention is based on the idea that apart from the additional acceleration of the articles under treatment , additionally the gravity thereof should be utilized. Thus there should be obtained - in addition to the rotative movement of the drum - an additional movement of the parts in axial direction of the drum. Thus the small articles in the drum would be subjected to three components of forces: first to centrifugal forces due to the rotative movement of the drum, second to centrifugal forces due to the travel of the drum along a circular path and finally to gravitational forces in the direction of the drum axis. The combination of these forces causes an agitation of the small articles which results in a most effective movement thereof and mixing of the parts with the polishing or cleaning agent and there is quasi obtained a great increase of the weight of the articles and consequently a much better polishing or cleaning action.

Accordingly, the invention provides an apparatus which comprises at least two rotating drums, arranged on substantially vertical axes and being positioned symmetrically to a central axis about which the drums can ascribe a movement along a circular path, the two drums being provided on a carrier boom which turns about a vertical axis.

The invention will now be described in connection with the accompanying drawings showing a practical embodiment of the invention by way of example.

Figure 1 is an elevational section of the new apparatus, while Figure 2 is a plan view thereof.

On a vertical stand 1 is provided turnably the carrying boom 2 and its bearing 3· This bearing is composed of two ball bearings, the axis A—A of which is in the vertical. On the carrying boom there are provided, held in vertical pressure bearings 4 and 5 , two rotating drums 6 and 7 respectively. The two rotating drums 6 and 7 have their axes B—B in parallel and are positioned symmetrically in relation to the axis A—A of the bearing 3 of the carrying boom 2. The two ball bearings of the drums are connected with one another by sleeve 8, 9 respectively. Into these sleeves 8 and 9 pins 6a and 7a being integral with the bottom of the drums 6 and 7 are fittingly inserted. The drive for the drums is provided by chain-gears consisting of sprockets 10-11 which are keyed to the stand 1, and further sprockets 12 and 13 which are provided fixedly on the sleeves 8-9. T e chains are indicated by dash dotted lines 14. The drive of the carrying boom 2 is provided by a speed-controlled motor 15- The sprockets 12 and 13 and consequently the drums 6 and 7 are thus driven synchronously.

It will be seen that the articles filled into the drums are subject to a centrifugal acceleration which is much greater than the acceleration due to earth gravity. In other words, the articles to be treated are quasi subjected to an increase of their own weight. In this way there is obtained greater frictional action between the individual pieces and a greater pressure is being exerted by the pieces onto each other, thereby the grinding of sharp edges and roughness due to the cast is effected in a quick and efficient manner. The said accelerating forces act horizontally, i.e. in parallel to the ground. At the same time the goods are subjected to gravity in the direction of the axis of the drums.

The combination of the centrifugal forces with the force of gravity results in a very good agitation and mixing of the articles to be treated. It has been found that the articles roughly perform a movement along a helical line upwardly and then they slide down again along a helical line to the bottom of the drum. Thus the agitation is much better and more effective than it was with drums where the latter rotated about horizontal axes and the gravity could not act in the direction of the said axis.

It is not absolutely necessary to have the axis of rotation of the drums in the vertical, certain deviations therefrom would be within the scope of the invention. It is sufficient if only a smaller component of the gravity remains active in the direction of the axis and deviations up to about 45° would be possible. However, it should not be forgotten that in practice such an oblique position of the axis would cause some complications in erecting the apparatus. It would also be within the scope of the Thus it would be possible to subject drums which rotate about horizontal axes to blows by air streams which act laterally on the drums. All these means, however, would cause certain complications as compared with the arrangement according to the invention which permits gravity to act in the direction of the axis.

It would be within the scope of the invention to provide more than two drums on the carrier boom which in that case would be manifold, i.e. star or spider shaped and the drums would be distributed symmetrically around the axis A—A. In such a case equal quantities of articles should be filled into the individual drums.

Instead of chain gears ordinary toothed-wheel gears could be used. The drums may have a lid in which a vent opening should be provided, so as to prevent rise of pressure in the interior. There is no danger or likelihood that the chemicals filled into the drum could escape through such a vent since it has been experienced that due to the motions of the drum the opening is always out of reach of the liquid. It would even be possible to provide no lid at all and just to provide an inwardly extending flange around the edge of the drum. The number of revolutions of the carrier and that of the individual drums need not be related to one another. The drums may perform a number of revolutions as is common now with such drums, that is to say between 1/10 up to 2 revolutions per second while the boom would rotate at higher speed, i.e. with 1 to 10 revolutions per second. In order to give an example out of the practice, with a diameter of the circular path of about 1 meter the boom would advantageously perform 185 revolutions per minute which gives good results.

Claims (3)

WHAT I CLAIM ISi

1. An apparatus for treating small articles in rotating drums (6,7) which are supported by means of vertical pressure bearings (4,5) in distanced relation to one another on a horizontal carrying boom (2) in a manner to be revolvable about a vertical axis, characterised thereby that the carrying boom (2) is composed of mirror- mage symmetrical troughs and is held by bearings (3) on a stationary vertical support (1) and further thereby that on the said support between the said bearings (3,3) there is provided at least one toothed wheel and. thereby that pressure bearings (4/8, 5/9) are provided wherein the revolving drums can be inserted, the said pressure bearings being fitted each with a toothed wheel (12,13) which meshes directly or indirectly with corresponding toothed wheels between the bearings (3,3).

2. An apparatus according to Claim 1, characterized thereby that for an indirect drive of the drums sprocket wheels are provided which are connected by means of chains (14) with corresponding sprocket wheels (10,11) on the support (l).

3. An apparatus according to Claim 1, characterized thereby that for a direct drive toothed wheels are provided with corresponding toothed wheels on the support. Attorneys or App cants.