GB2035419A

GB2035419A - Coal cutter picks and pick boxes

Info

Publication number: GB2035419A
Application number: GB7940796A
Authority: GB
Original assignee: Tungsten Carbide Developments Ltd
Current assignee: Tungsten Carbide Developments Ltd
Priority date: 1978-11-30
Filing date: 1979-11-26
Publication date: 1980-06-18

Abstract

A coal cutter pick box (16) having an aperture (14) for the reception of the shank (12) of a coal cutter pick (10) a cylindrical pin (18) extending transversely across the aperture for engagement in a transverse slot (20) formed in the pick shank, the transverse slot having a flared mouth tapering down to a restricted opening into a circular location (22) for the cylindrical pin (18). The cylindrical pin (18) may be surrounded by a resilient sleeve (26). <IMAGE>

Description

SPECIFICATION An improvement in or relating to coal cutter picks and pick boxes The invention relates to coal cutter picks and pick boxes therefor and has for its object to provide an improvement therein.

Various ways have previously been proposed for retaining coal cutter picks in pick boxes, for example retaining means including plungers urged by resilient means into engagement with grooves formed in the shanks of the picks which they are to retain in position. However, such retaining means require to be made with relatively high precision so that the picks are safely retained in position without danger of inadvertent release and so that a substantially pre-determined force is required to secure a pick in its pick box and to release it therefrom.

The object of the invention is to provide a retaining means which inherently is affected very little, if at all, by slight dimensional variations between the picks which are to be retained in position thereby.

According to one aspect of the invention, there is provided a coal cutter pick box having an aperture for the reception of the shank of a coal cutter pick, a cylindrical pin extending transversely across the aperture for engagement on a transverse slot formed across the end of the shank of the pick which is to be retained in the pick box, the transverse slot which is formed across the end of the shank of the pick having a flared mouth tapering down to a restricted opening into a circular location for the cylindrical pin in the pick box, the arrangement being such that when the shank of the pick has been entered into the aperture of the pick box it can be forced into its fully engaged position so that the cylindrical pin is engaged in the circular location within the shank to retain the pick in its working position.The cylindrical pin will preferably be surrounded by a resilient sleeve which is a tight push fit through the restricted opening into the circular location in the pick shank. The cylindrical pin will preferably have enlargements at its opposite ends which are in interference fit in aligned bores at opposite sides of the aperture in the pick box.

According to a further aspect of the invention, there is provided a coal cutter pick adapted to be retained in a pick box as described above, that is to say having a shank which can be entered into the aperture in the pick box, the shank having a transverse slot formed across its end, said slot having a flared mouth tapering down to a restricted opening into a circular location for the cylindrical pin in the pick box.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which Figure lisa part-sectional side view of a pick and pick-box combination embodying the invention, Figure 2 is a sectional view on the line 2-2 in Figure 1,and Figure 3 is a sectional view on the line 3-3 in Figure 1.

Referring now to the drawings, the coal cutter pick 10 there illustrated is shown to be provided with a shank 12 of rectangular cross section which is received in an aperture 14 of complementary shape in a pick box 16.

A cylindrical pin 18 extends transversely across the aperture 14 of the pick box and when the pick is located in position in the pick box the pin is engaged in a transverse slot 20 formed across the end of the shank of the pick as shown. The transverse slot which is formed across the end of the shank has a flared mouth tapering down to a restricted opening into a circular location 22 for the cylindrical pin, the arrangement being such that when the shank of the pick has been entered into the aperture of the pick box it can be forced into its fully engaged position so that the cylindrical pin is engaged in the circular location within the shank to retain the pick in its working position.

As best seen in Figure 2, the cylindrical pin is provided with enlargements 24 at its opposite ends which are an interference fit in aligned bores at opposite sides of the aperture in the pick box. The intermediate length of the pin is surrounded by a resilient rubber sleeve 26 and it is this which is a tight push fit through the restricted opening into the circular location in the pick shank.

It will be seen that the pick retaining means are of very simple form and it has been found that this form of retaining means in very effective yet relatively cheap to produce and trouble free in use. Twill be understood that the rubber sleeve surrounding the intermediate length of the pin allows a relatively wide degree of tolerance in the various dimensions of the pick and pick box. That is to say, the rubber sleeve allows for the slot not being formed exactly at the centre of the shank of the pick and also allows for slight variations in the diameter of the circular location for the cylindrical pin.

1. A coal cutter pick box having an aperture for the reception of the shank of a coal cutter pick, a cylindrical pin extending transversely across the aperture for engagement in a transverse slot formed across the end of the shank of the pick which is to be retained in the pick box, the transverse slot which is formed across the end of the shank of the pick having a flared mouth tapering down to a restricted opening into a circular location for the cylindrical pin in the pick box, the arrangement being such that when the shank of the pick has been entered into the aperture of the pick box it can be forced into its fully engaged position so that the cylindrical pin is engaged in the circular location within the shank to retain the pick in its working position.

2. A coal cutter pick box according to claim 1, in which the cylindrical pin is surrounded by a resilient sleeve which is a tight push fit through the restricted opening into the circular location in the pick shank.

3. A coal cutter pick box according to either one of the preceding claims, in which the cylindrical pin has enlargements at its opposite ends which are an interference fit in aligned bores at opposite sides of

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION An improvement in or relating to coal cutter picks and pick boxes The invention relates to coal cutter picks and pick boxes therefor and has for its object to provide an improvement therein. Various ways have previously been proposed for retaining coal cutter picks in pick boxes, for example retaining means including plungers urged by resilient means into engagement with grooves formed in the shanks of the picks which they are to retain in position. However, such retaining means require to be made with relatively high precision so that the picks are safely retained in position without danger of inadvertent release and so that a substantially pre-determined force is required to secure a pick in its pick box and to release it therefrom. The object of the invention is to provide a retaining means which inherently is affected very little, if at all, by slight dimensional variations between the picks which are to be retained in position thereby. According to one aspect of the invention, there is provided a coal cutter pick box having an aperture for the reception of the shank of a coal cutter pick, a cylindrical pin extending transversely across the aperture for engagement on a transverse slot formed across the end of the shank of the pick which is to be retained in the pick box, the transverse slot which is formed across the end of the shank of the pick having a flared mouth tapering down to a restricted opening into a circular location for the cylindrical pin in the pick box, the arrangement being such that when the shank of the pick has been entered into the aperture of the pick box it can be forced into its fully engaged position so that the cylindrical pin is engaged in the circular location within the shank to retain the pick in its working position.The cylindrical pin will preferably be surrounded by a resilient sleeve which is a tight push fit through the restricted opening into the circular location in the pick shank. The cylindrical pin will preferably have enlargements at its opposite ends which are in interference fit in aligned bores at opposite sides of the aperture in the pick box. According to a further aspect of the invention, there is provided a coal cutter pick adapted to be retained in a pick box as described above, that is to say having a shank which can be entered into the aperture in the pick box, the shank having a transverse slot formed across its end, said slot having a flared mouth tapering down to a restricted opening into a circular location for the cylindrical pin in the pick box. In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which Figure lisa part-sectional side view of a pick and pick-box combination embodying the invention, Figure 2 is a sectional view on the line 2-2 in Figure 1,and Figure 3 is a sectional view on the line 3-3 in Figure 1. Referring now to the drawings, the coal cutter pick 10 there illustrated is shown to be provided with a shank 12 of rectangular cross section which is received in an aperture 14 of complementary shape in a pick box 16. A cylindrical pin 18 extends transversely across the aperture 14 of the pick box and when the pick is located in position in the pick box the pin is engaged in a transverse slot 20 formed across the end of the shank of the pick as shown. The transverse slot which is formed across the end of the shank has a flared mouth tapering down to a restricted opening into a circular location 22 for the cylindrical pin, the arrangement being such that when the shank of the pick has been entered into the aperture of the pick box it can be forced into its fully engaged position so that the cylindrical pin is engaged in the circular location within the shank to retain the pick in its working position. As best seen in Figure 2, the cylindrical pin is provided with enlargements 24 at its opposite ends which are an interference fit in aligned bores at opposite sides of the aperture in the pick box. The intermediate length of the pin is surrounded by a resilient rubber sleeve 26 and it is this which is a tight push fit through the restricted opening into the circular location in the pick shank. It will be seen that the pick retaining means are of very simple form and it has been found that this form of retaining means in very effective yet relatively cheap to produce and trouble free in use. Twill be understood that the rubber sleeve surrounding the intermediate length of the pin allows a relatively wide degree of tolerance in the various dimensions of the pick and pick box. That is to say, the rubber sleeve allows for the slot not being formed exactly at the centre of the shank of the pick and also allows for slight variations in the diameter of the circular location for the cylindrical pin. CLAIMS

3. A coal cutter pick box according to either one of the preceding claims, in which the cylindrical pin has enlargements at its opposite ends which are an interference fit in aligned bores at opposite sides of the aperture in the pick box.

4. A coal cutter pick adapted to be retained in a pick box as claimed in any one of the preceding claims, that is to say having a shank which is entered into the aperture in the pick box, the shank having a transverse slot formed across its end, said slot having a flared mouth tapering down to a restricted opening into a circular location for the cylindrical pin in the pick box.

5. In combination, a coal cutter pick box as claimed in any one of claims 1 to 3, and a coal cutter pick as claimed in claim 4, the shank of the pick being retained in the aperture in the pick box by the cylindrical pin in the pick box being received in the circular location in the shank of the pick.

6. A coal cutter pick box constructed, arranged and adapted to be used to retain a coal cutter pick, substantially as hereinbefore described, with referpence to and as illustrated by the accompanying drawings.

7. A coal cutter pick constructed, arranged and adapted to be located in a pick box, substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.