Metal working – Method of mechanical manufacture – Combined manufacture including applying or shaping of fluent...
Patent
1994-11-22
1996-08-20
Arbes, Carl J.
Metal working
Method of mechanical manufacture
Combined manufacture including applying or shaping of fluent...
72340, 72352, 723546, 72359, B23P 2500
Patent
active
055466478
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a method of making an ejector tube for molds in general, though it is intended for application in particular with injection mold. The method is based on a series of stages of work carried out on a length of tubing of suitable length and diameter so as to achieve, through the minimum number of operations, the shaping of the ejector tube which serves as the guide for the ejectors used in molds, with both the ejector tube and the ejector being held in place by a fixing head.
The ejector tubes used as guides for ejectors linked to their fixing heads and included in injection moulds are conventionally produced from a bar or rod which is subjected to a series of processes: first, one of the ends is worked to produce the head, which is oversized with respect to the rest of the body; next, an axial bore is cut all the way through, and then suitably machined to give two diameters; it is then trued, and further operations are performed until the ejector tube sought is obtained.
The producing the ejector tube in the conventional manner, the starting point is a solid bar which, since its bore has to be drilled out, entails a loss of material, and furthermore this bar initially is very heavy. For example, to produce a standard ejector tube measuring 400 mm in length with a bore diameter of 8 mm and an outside diameter of 12 mm, the starting point is a bar of metal whose total weight is approximately 1,290 grams.
Furthermore, special machine tools are needed to produce it. As a consequence of all this, fourteen to sixteen different operations have to be performed--a long and laborious process.
It must also be borne in mind that, since material has to be removed to produce the bore, molecules will be broken, thereby reducing elasticity in the mechanical strength of the end product.
Another physical problem which cannot be eliminated arises during the heat treatment, since the various molecular masses which make up the product have varying thicknesses, and this makes the cooling stage in the hardening fragile, plastic deformations arising which require a special, additional truing process.
Finally, it must be pointed out that, in conventionally produced ejector tubes, when the tube has to be cut to length, the cut has to be made at the upper end, since naturally this operation is performed after attaching the piece to the appropriate fixing head. Since this area of the piece is the one in which the ejector and the tube itself are close-fitted, and since the cutting reduces the size of this area, that close-fit quality is lost.
SUMMARY OF THE INVENTION
The proposed method was designed to resolve these problems fully by starting from a length of tubing, which to begin with provides a considerable saving in weight, since to produce a tube of approximately the same size as the one referred to in the previous section, the weight involved in the procedure of this invention is approximately 220 grams, as against the 1,290 grams of the total weight of the piece which is the starting point for the conventional method.
Secondly, the ejector tube is designed to be correctly and effectively held by means of a fixing head which was claimed as a novelty in utility model 9103746 by the same applicant.
Among noteworthy advantages is the fact that no material has to be removed, and so no molecules are broken. Also the ejector tube is adjusted or cut at the lower end by virtue of its placing on the relevant fixing heads, and it can be removed from the top end of these, the lower close-fitted part being reduced.
In particular, the method of this invention, starting from a tube of suitable length and inside and outside diameters, comprises the following operational stages:
Cutting the length of tubing to the desired length, leaving some excess to allow for subsequent truing.
Reducing the diameter in one of the end sections of the tube, with a specific tolerance for performing the machining and achieving total concentricity.
Performing a pre-truing operation outside to approach
REFERENCES:
patent: 126610 (1872-05-01), Wood
patent: 1198250 (1916-09-01), Malo
patent: 1483947 (1924-02-01), Morse
patent: 1566645 (1925-12-01), Breeze
patent: 2344285 (1944-03-01), Cormode
patent: 2377191 (1945-05-01), Teachout
patent: 2548702 (1951-04-01), Chamberlain
patent: 2965965 (1960-12-01), Allan
patent: 3224243 (1965-12-01), Van Deberg
patent: 4722216 (1988-02-01), Fencl
patent: 4928507 (1990-05-01), Staat et al.
patent: 5184495 (1993-02-01), Chunn et al.
Rationelle Entformung von Spritz 94 Bteilen mit Auswerf,-Normahen Kunststoff Berater Apr. 1986, pp. 27-29.
Arbes Carl J.
Striker Michael J.
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