GB2200063A - Work guide - Google Patents

Abstract

A work guide incorporates a hollow resilient guiding sleeve 4 supported by brackets 2, 3 on base member 1. External rings 11, 11a loosely surround the sleeve 4, and each ring is provided with pressure screws 12 for adjustably controlling radial contraction of the resilient guiding sleeve. The device may be used as an entry or delivery guide for tubes or sections in roller straightening machines. <IMAGE>

Description

STRAIGHTENER GUIDE The present invention relates to plastic metal working and has specific reference to a straightener guide.

The invention may be of utility as an item of entrance and delivery end arrangements of straighteners with cross rolls used to work thin-walled tubing to close tolerances.

The guide provided in accordance with the present invention may also be used in roller straighteners as a means of guiding and straightening intricate light-gauge shapes.

There is known a guide of straightener (cf. USSR Inventor's Certificate No. 634812, IPC 321D 3/00; filed July 6, 1977; published November 3O, 1978; Gazette No. 44) the guiding means whereof consisting of sleeves in a resilient material is contained in a stiff cylindrical body and restrained axially by an end plate of the body. Means of controlling radial contraction of the resilient guiding means are provided in the body.

The resilient guiding means of the known guide rapidly wears away under the pressure imposed by the end faces of the tubes which are being straightened. A replacement of the worn sleeves calls for taking the guide apart which cannot be done without stopping the straightener. The ill -efect of such down periods on rpoductivity is obvious.

Apart from that, the resilient sleeves of the known guide lend themselves to radial sdjustments over a small range, and quality straightening of the ends of small -diameter tubes becomes therefore a problem.

The main object of the present invention is to provide a guide of straightener the features of design whereof would ensure long service life of the resilient guiding means and quality straightening of thin-walled tubes and other light-gauge shapes of a wide range without difficulty.

This object is realized by a guide of straightener comprising a base plate, stiff brackets fitted to the base plate, a resilient hollow guiding means supported in the brackets and used to feec the work and means of controlling radial contraction of the resilient guiding means wherein according to the invention the resilient guiding means is provided in the form of a continuous sleeve with a number of external stiff rings, each being a slack-running fit thereto, whereby at least some of the means of controlling radial contraction of the resilient guiding means are located on the stiff rings.

The continuous resilient sleeve possess resiliency of a high order which contributes to quality straightening of small-diameter tubes at their ends.

The stiff rings forming slack#running fits with the resilient guding means and provided with means of controlling radial contraction. of the sleeve can be shifted along this sleeve as some portions thereof wear away. The durability of the guide is increased in this way.

The means of controlling radial contraction of the resilient sleeve which are located on stiff rings provide for precise adjustments of the effective section of the sleeve at any point along thereof over a wide range without taking apart the guide and stopping the straightener.

All in all, the guide of straightener provided inac- cordance with the present invention has a durable guiding means rendering itself to adjustment or replacement without disassembling the guide and removing the straightener from production. The disclosed guide contributes to product quality, eliminating difficulties commonly experienced in straigh tending ends of tubes, especially when these are of a small diameter.

These and other advantages of the present invention are apparent from the following description of a preferred embodiment thereof given by way of example with reference to the accompanying drawings in which Figure n is a schematic side view, partly cut away, of the guide of straightener in accordance with the inven- tion; Figure 2 is a section on line Il-Il of Fig. 1; Figure 3 is a section on line Ill-Ill of Fig. 1; Figure 4 is a schematic sectional elevation of the guide of straightener according to the invention which is adapted to straighten light-gauge shapes in a roller straightener.

Referring to Fig. 1, the guide of straightener (referred as guide hereinafter) provided according to the invention comprises a stiff base plate 1, stiff brackets 2 and 3 attached to the ends of the base plate 1 and a resilient guiding means 4 in the form of a continuous sleeve supported in the brackets 2 and 3. The entry end of the resilient guiding means 4 has a cylindrical boss 5 with an internal flare 6 which facilitates the passage of the tube 7 to be straightened. The flare 6 joins a cylindrical medial portion 8 of the resilient gelding means 4 which comes into contact with the tube 7 in the course of a straightening operation. The resilient guiding means 4 is held fast in the bracket 2 by means of set screws 9 spaced equidistantly apart along the circumference of the bracket 2 and fits without restraint into the bracket 3.

The resilient guiding means 4 serves as passage for the tube 7 which is being straightened or or a shape in some other cases.

Girdling the resilient guiding means 4 with a clearance 10 are three metal rings 11, 11a (Figs 1,2,3) with pressure screws 12 which serve to control radial contraction of the guding means 4.

The metal rings 11, Ila may vary in number depending on the length of the tubes 7 subjected to straightening.

The number and location of the pressure screws 12 on the outside surface 13 (Fig. 2,3) of every ring may also vary.

In the described guide intended to straighten thin-walled tubes in a straightener with cross rolls, each of the metal rings 11 and lia has two pressure screws 12 located at diametrically opposite points. If screwed in, they compress the resilient guiding means 4 at two diametrically opposite points so that the bore of this means becomes an ellipse in section all the way along the active zone 14 (Fig. 1) where the pressure screws 12 are. in contact with the resilient guiding means 4.

In the ring 11 (Fig. 2), the pressure screws 12 are located along a horizontal axis 15. Therefore, if screwd in, they compress the resilient guiding means 4 to a point when its Sore is an ellipse in section which extends more along a vertical axis 16 than along the horizontal one 15.

In the ring Ila (Fig. 3), the pressure screws 12 are located along the vertical axis 16. Therefore, it screwed in, they compress the resilient guiding means 4 to a point when its bore is an ellipse in section which extends more along the horizontal axis 15 than along the vertical one 16.

So, a number of elliptical bore lengths compressed to various degrees of out-of-round and oriented in different ways are set up in the resilient guiding means 4, forming its controllable effective section.

In another realization of the guide, when the plan is to use it for straightening light-gauge open shapes on a roller straightener, the metal ring 11b (Fig. 4) has three pressure screws 12 which compress the resilient guiding means 4 so that its cross section approaches the shape of an angle 17 fed for straightening.

The resilient guiding means 4 can be made of any wear -resistant material, e.g. polyurethane.

The disclosed guide is prepared for operation and operated in the following way.

The resilient guiding means 4 is inserted into the stiff brackets 2, 3 of the base plate 1 and attached to the bracket 2 by the set screws 9, or in some other way.

The base plate 1 with the brackets 2 and 3 is placed at the entrance end of the straightener (not shown).

On applying the metal rings 11, 11a effortlessly to the medial portion 8 of the resilient guiding means 4, the pressure screws 12 are screwd into the rings. In compressing the resilient guiding means 4 with the aid of pressure screws 12, the bore of the means 4 is given an elliptical readily controllable configuration which is in fact the effective section of the guiding means 4.

Every tube 7 passed before straightening through the guide comes in contact with the guiding means 4, bringing about local wear of the active zones 14. To rectify the defect, the pressure screws 12 of e.g. the ring 11 are released and the ring 11 turned through an angle which brings into action other active zones 14, providing so for a firm contact between the tube 7 and the resilient guding means 4.

In the event of an extensive wear of the active zones 14 which cannot be eliminated by turning either the ring 11 or the ring Ila, the remedy is to shift these rings alongwise the resilient guding means 4 and repeat the operation of setting up the effective section thereof. No disassembling and taking down the guide are required in this case so that any readjustment is not associatted with a loss of productivity.

Summing up, the seasons rendering the disclosed guide practical for handling thin-walled tubes and slender shapes are as follows: - durability of the resilient guiding means; - simplicity of adjustment of the guide for operation; - elimination of down periods of the straightener used with the guide; - good surface finish of tubes possessing extra spring (freedom from indents, creases and other defects); - extended range of products which can be handled (applies to extra thin-walled tubes and very slender shapes); - straightening of tubes over their entire length, the ends included.

Claims (2)

1. A straightener guide comprising a base plate, stiff brackets fitted to the base plate, a resilient hollow guiding means supported in the brackets and used to feed the work and means of controlling radial contraction-of the resilient guiding means, whereby the resilient guiding means is provided in the form of a continuous sleeve with a number of external stiff rings, each being a slack-running fit thereto, and at least some of the means of controlling radial contraction of the resilient means are located on the stiff rings.

2. A straightener guide as claimed in claim 1 essentially as described hereinabove and illustrated in the accompanying drawings.