GB2077646A - Drawing tool - Google Patents

Abstract

A tool for drawing items with lubricant under pressure on a drawing bench comprises a housing (1) accommodating a clamped conical split bushing (2) inside which series- arranged in the direction of motion of an item (3) being drawn and contacting one another are a pressure bushing (4) and a working die (6). A sealing floating bushing (8) is situated inside a bore of the clamped conical split bushing (2) in a manner to envelope the pressure bushing (4) and a 0.1 to 0.3-th part of the length of the working die (6). <IMAGE>

Description

SPECIFICATION Tool for drawing items with lubricant under pressure The invention relates to devices for working metals, and more particularly to tools for drawing items with lubricants under pressure.

The invention can be used with advantage for drawing items of any types and for any applications (for example, wire, rods, tubes) on all existing drawing benches.

The invention provides a tool comprising a housing accommodating a clamped conical split bushing inside which series-arranged in the direction of motion of an item being drawn and contacting one another are a pressure bushing, a sealing element and at least one working die, wherein, according to the invention, is provided with a sealing floating bushing situated with a radial clearance inside a bore of the clamped conical split bushing in a manner that it envelops the pressure bushing and a 0.1 to 0.3-th part of the length of the working die.

It is advantageous to provide the clamped conical split bushing with at least one longitudinal slit in the part thereof enveloping the sealing floating bushing.

The invention enhances the reliability of the seal exposed to thermal and mechanical deformations, and, in consequence, makes possible increases in drawing rate and in drafts and minimizes the frequency of ruptures of an item as it is being drawn.

Another advantage is that the invention decreases the probability of a working die failing because of excessive wear or splitting.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a general view of a tool for drawing items with a lubricant under pressure (longitudinal section), according to the invention; Figure 2 is a general view of a clamped conical split bushing of Fig. 1 (represented as an isometric drawing), according to the invention.

The illustrated tool for drawing items with a lubricant under pressure comprises a clamped conical split bushing 2 (Figs. 1, 2) mounted inside a housing 1 (Fig. 1). The bushing 2 (Fig. 1 ) accommodates series-arranged in the direction of motion of an item 3 being drawn (hereafter termed a wire 3) contacting one another are pressure bushing 4, a sealing element 5 and a working die 6. The space between the bushing 4 and the die 6 is filled with a lubricant 7.

A bore in the bushing 2 receives a sealing floating bushing 8 situated with a radial clearance relative to the bushing 2 in a manner that it envelops the bushing 4 and a 0.2-th part of the length of the die 6. A part of the bushing 2 (Figs. 1, 2), which envelops the bushing 8, is provided with a slit 9. A tightening cap 10 is connected to the housing 1.

On assembly of the tool for drawing wire 3 (Fig. 1) with the lubricant 7 under pressure, the working die 6 is compressed radially to a greater degree irrespective of the diameter of the pressure bushing 4, so that the risk of the working die 6 failing because of splitting is substantially minimized.

The tool for drawing wire with lubricant under pressure operates in the manner below.

As the wire 3 passes through the pressure sleeve 4, it self-pumps the lubricant 7 and thus creates a high pressure in the space between the sleeve 4 and the die 6. In so doing, the surfaces of the wire 3 and of the working die 6, which tend to rub one against the other, are separated to enable an increase in the drawing rates and the drafts and a decrease in the wear of the working die 6.

The provision of both a bore in the clamped conical split bushing 2 and of a longitudinal slit 9 in it (Fig. 2) makes possible the use of the bushings 2 and 8 as a set, so simplifying the assembly/disassembly of the tool according to the invention.

1. A tool for drawing items with lubricant under pressure, comprising a housing accommodating a clamped conical split bushing inside which series-arranged in the direction of motion of the item being drawn and contacting one another are a pressure bushing, a sealing element and at least one working die, a sealing floating bushing being situated with a radial clearance inside a bore in the clamped conical split bushing in a manner to envelope the pressure bushing and a 0.1 to 0.3-th part of the length of the working die.

2. A tool as claimed in claim 1, wherein the clamped conical split bushing is provided with at least one longitudinal slit in the part thereof enveloping the sealing floating bushing.

3. A tool for drawing items with lubricant under pressure substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Tool for drawing items with lubricant under pressure The invention relates to devices for working metals, and more particularly to tools for drawing items with lubricants under pressure. The invention can be used with advantage for drawing items of any types and for any applications (for example, wire, rods, tubes) on all existing drawing benches. The invention provides a tool comprising a housing accommodating a clamped conical split bushing inside which series-arranged in the direction of motion of an item being drawn and contacting one another are a pressure bushing, a sealing element and at least one working die, wherein, according to the invention, is provided with a sealing floating bushing situated with a radial clearance inside a bore of the clamped conical split bushing in a manner that it envelops the pressure bushing and a 0.1 to 0.3-th part of the length of the working die. It is advantageous to provide the clamped conical split bushing with at least one longitudinal slit in the part thereof enveloping the sealing floating bushing. The invention enhances the reliability of the seal exposed to thermal and mechanical deformations, and, in consequence, makes possible increases in drawing rate and in drafts and minimizes the frequency of ruptures of an item as it is being drawn. Another advantage is that the invention decreases the probability of a working die failing because of excessive wear or splitting. The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a general view of a tool for drawing items with a lubricant under pressure (longitudinal section), according to the invention; Figure 2 is a general view of a clamped conical split bushing of Fig. 1 (represented as an isometric drawing), according to the invention. The illustrated tool for drawing items with a lubricant under pressure comprises a clamped conical split bushing 2 (Figs. 1, 2) mounted inside a housing 1 (Fig. 1). The bushing 2 (Fig. 1 ) accommodates series-arranged in the direction of motion of an item 3 being drawn (hereafter termed a wire 3) contacting one another are pressure bushing 4, a sealing element 5 and a working die 6. The space between the bushing 4 and the die 6 is filled with a lubricant 7. A bore in the bushing 2 receives a sealing floating bushing 8 situated with a radial clearance relative to the bushing 2 in a manner that it envelops the bushing 4 and a 0.2-th part of the length of the die 6. A part of the bushing 2 (Figs. 1, 2), which envelops the bushing 8, is provided with a slit 9. A tightening cap 10 is connected to the housing 1. On assembly of the tool for drawing wire 3 (Fig. 1) with the lubricant 7 under pressure, the working die 6 is compressed radially to a greater degree irrespective of the diameter of the pressure bushing 4, so that the risk of the working die 6 failing because of splitting is substantially minimized. The tool for drawing wire with lubricant under pressure operates in the manner below. As the wire 3 passes through the pressure sleeve 4, it self-pumps the lubricant 7 and thus creates a high pressure in the space between the sleeve 4 and the die 6. In so doing, the surfaces of the wire 3 and of the working die 6, which tend to rub one against the other, are separated to enable an increase in the drawing rates and the drafts and a decrease in the wear of the working die 6. The provision of both a bore in the clamped conical split bushing 2 and of a longitudinal slit 9 in it (Fig. 2) makes possible the use of the bushings 2 and 8 as a set, so simplifying the assembly/disassembly of the tool according to the invention. CLAIMS

1. A tool for drawing items with lubricant under pressure, comprising a housing accommodating a clamped conical split bushing inside which series-arranged in the direction of motion of the item being drawn and contacting one another are a pressure bushing, a sealing element and at least one working die, a sealing floating bushing being situated with a radial clearance inside a bore in the clamped conical split bushing in a manner to envelope the pressure bushing and a 0.1 to 0.3-th part of the length of the working die.

2. A tool as claimed in claim 1, wherein the clamped conical split bushing is provided with at least one longitudinal slit in the part thereof enveloping the sealing floating bushing.

3. A tool for drawing items with lubricant under pressure substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.