US 2828586 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
April 1, 1958 H. LIST ET AL 2,828,586
ARRANGEMENT FOR GRINDING THE INSIDE WALLS OF CYLINDRICAL CONTAINERS Filed June 28, 1956 ERNST GRANACHER ilniteti States Patent ARRANGEMENT FUR GRINDING THE INSIDE WALLS OF CYLINDRICAL CONTAINERS Heinz List and Friedrich Friisch, Pratteln, Switzerland, and Ernst Granacher, Sackingen, Germany, assignors to Buss A. G., Basel, Switzerland Application June 28, 1956, Serial No. 594,514
Claims priority, application Switzerland June 29, 1955 1 Claim. (Cl. 51-141) In the manufacture of chemical apparatus in particular, the necessity arises for grinding the inside walls of cylindrical containers of all kind which are made of stainless steel, since thereby the resistibilty of the material against the corrosive action of the chemical substances is considerably increased.
To such end, the walls of drums and the like have so far been ground with the aid of electrically operated and manually guided grinding means. The operator together with his grinding apparatus was positioned inside the drum and wearing a protective mask against the development of dust, had to perform this operation in a tedious and time-c0nsuming manner. Such grinding operation was expensive and even dangerous when carried out without any protective mask. The resulting grinding pattern was irregular.
The present invention provides an arrangement for grinding the inside walls of cylindrical containers which permits the above mentioned disadvantages and drawbacks to be avoided. This arrangement is characterized by a grinding apparatus mounted on an arm which automatically performs a limited reciprocal movement.
A preferred embodiment of the invention is illustrated, by way of example, in the accompanying drawing, in which- Fig. 1 is a side view of the arrangement, and
Fig. 2 is a front view thereof.
The arrangement comprises a frame a with vertical guides b in which is guided a slide 0 being vertically adjustable by means of a spindle d. In slide c is mounted a horizontal arm e which is reciprocated via a variable ratio gearing f, the speed of this arm and thus of the grinding operation being variable. In the terminal positions of arm 2 the movement thereof is interrupted by limit switches g and dogs h which are adjustably mounted on the arm. This results in an automatic reciprocating movement of arm e.
On the forward end of arm e is disposed a grinding apparatus i of a construction known per se which is driven by an electric motor k. Grinding apparatus i and motor k are mounted on a cantilever lin flexible bearings m, for example by using rubber sleeves. The pressure under which the grinding tape 0, which is trained over a wheel n, is urged against the interior wall p of the drum, depends on the dead load of apparatus i and motor k. This pressure may be still further increased, also during the grinding operation, by angularly moving about its own axis the cantilever l on which are disposed the flexible bearings m, by means of a handwheel q.
The drum wall is constructed of circularly rolled sheets, and consequently the drum inside diameter is not absolutely uniform. By virtue of mounting the grinding apparatus i in the flexible bearings m, however, the grinding tape 0 nevertheless can adapt itself to these deviations from the theoretical diameter.
The pressure of the grinding apparatus on the drum wall acts downwardly and is accommodated by the rolls r of a drum-rotating device s of a construction known per se, which is driven by variable ratio gearing t, whereby the rate of grinding may also be varied.
A suction device it which is only schematically shown, serves the purpose of rapidly removing the metal dust produced by the grinding operation.
What we claim is:
Apparatus for grinding the inside walls of cylindrical containers comprising an external support for the container to be ground, a frame adjacent said support, external vertical guides on said frame, a slide mounted on said guides, a motor and gearing mounted on said slide, a cross-arm extending on one side of said slide into the cylindrical container to be ground and mounted on said slide for limited reciprocal movement by said motor and gearing, a cantilever arm mounted on the end of said cross-arm projecting into the cylindrical container, said cantilever arm and cross-arm having parallel axes, means on said cross-arm for adjusting the distance between the axes of said cantilever arm and said cross-arm, resilient bearings on said cantilever arm, and an internal grinding apparatus and a motor therefor mounted in said resilient bearings on said cantilever arm, said grinding apparatus comprising an endless grinding belt.
References Cited in the file of this patent UNITED STATES PATENTS 2,279,782 Fowler Apr. 14, 1942 2,445,391 Elmes et a1. July 20, 1948 2,470,221 Mott May 17, 1949 2,768,481 Thomasco Oct. 30, 1956