GB2104174A - Improvements relating to machine tools - Google Patents

Abstract

A screen for a machine tool comprises a number of elongate mounting members (12) and a plurality of screening members (14) secured to each mounting member (12) as cantilevers therefrom. Each screening member (14) is provided with an elongate slot (20), and the screen comprises securing means (22, 24, 26, 28, 30, 32) by which the screening members may individually be clamped to its associated mounting member (12). Adjacent side edges of the screening members (14) are provided with inter-engaging formations (16, 18), to provide for mutual support between adjacent screening members whilst permitting relative longitudinal movement therebetween. <IMAGE>

Description

SPECIFICATION Improvements relating to machine tools This invention is concerned with improvements relating to machinetools, and in particularto screens for machine tools.

In machine tool operations, it is desirable to utilise a screen or guard to protect an operative against material cut be a cutting head of the machine and thrown from the workpiece.

A machine tool usually has considerable versatility in the manner in which it operates on a workpiece, and it is desirable that the screen be positionally adjustable to provide for maximum safety in accordance with the particular operation being carried out.

Further however, in machine tools of the kind in which the workpiece is moved in relation to the cutting head of the machine, it is often necessary to provide in the screen an opening through which the or some of the moving parts of the machine (which may include the workpiece itself) may pass. Clearly of course it is desirable to afford such an opening which is as small as practicable, to reduce the chances of cut material being thrown therethrough.

Conventionally, difficulty is encountered in providing the screen with such versatility, whilst ensuring that the screen meets the requirements of rigidity, without obscuring the view of the operative of the machine unduly.

With these difficulties in mind, it is one of the various objects of this invention to provide a screen for a machine tool which provides a high degree of protection for an operative using the machine tool without undue complications and expense.

According to this invention there is provided a screen for a machine tool and comprising an elongate mounting member, a plurality of elongate screening members, and securing means by which the screening members may be mounted on the mounting member, the securing means being movable between an inoperative condition in which one or more screening member may be moved longitudinally thereof relative to the mounting member and an operative condition in which such securing member is secured to the mounting member.

Preferably the screen comprises supporting means which is operative between adjacent screening members to provide for mutual support whilst permitting relative longitudinal movement therebetween.

In this manner, the screening members of the screen may be individually positionally adjusted transversely of the mounting member as may be desired, and may be secured in such desired positions, the support afforded between adjacent screening members ensuring a high degree of strength of the screen and resistance to movement as may otherwise be caused by vibration of the machine tool.

The mounting member may be adapted to be secured to a fixed part of the machine tool, whereby the screening members may derive their support through the mounting member from the machine tool, or the screen may rest on the machine tool, e.g.

on the bed thereof. Such latter alternatively may be employed particularly where the screen extends around two or more sides of the cutting head of the machine tool, the screen comprising two mounting members secured together, each of said mounting members supporting a plurality of elongate screening members.

If desired, the screening members may be secured to the mounting member by a collectively operable securing means, whereby on release of the securing means all the screening members may be positionally adjusted in relation to the mounting member and to one another.

Preferably however, each screening member is secured to the mounting member by an individually operable securing means, whereby any one screening member may be postionally adjusted in relation to the mounting member and the other screening members whilst said other screening members are retained in fixed position relative to the mounting member, the supporting means permitting relative movement between said one screening member and each adjacent screening member.

However, it is envisaged that a plurality of securing means may be provided, each being operable collectively to secure a relatively small number of adjacent screening members, such as two or three.

The supporting means is conveniently afforded by formations on the longitudinal side edges of each of the screening members which are adapted to co-act with formations on the longitudinal side edges of adjacent screening members. The formations may be such as to enter into simple overlapping engagement, to provide for support of one screening member by an adjacent screening member in one direction transversely thereto, or into interfitting engagement, such as by tongue and groove formations, to provide for support on one screening member by an adjacent screening member in opposite directions transversely thereto.

Alternatively, elongate supporting members may be utilised, which may be secured to, to act between, adjacent longitudinal side edges of adjacent screening members, to transmit load and hence provide support between one screening member to an adjacent screening member.

Most conveniently, the screening members are secured as cantilevers to the mounting member, that is being supported thereby at a single point or over a single, relatively small, area.

Preferably the screening members are of plastics material, which is preferably transparent, but which may be opaque, and is conveniently produced by an injection moulding process from a thermoplastics material such as a polycarbonate.

According to this invention, there is also provided a screen for a machine tool and comprising an elongate mounting member, and a plurality of elongate screening members releasably secured to and extending transversely of the mounting member, supporting means being provided which is operative between adjacent screening members to provide for mutual support whilst permitting relative longitudinal movement therebetween.

There will now be given a detailed description, to be read with reference to the accompanying draw ings, of a machine tool comprising a screen which has been selected for the purposes of illustrating this invention by way of example.

In the accompanying drawings: FIGURE 1 is a perspective view of the machine tool, illustrating the screen thereof; FIGURE 2 is an enlarged perspective view of part of the screen; FIGURE 3 is an enlarged sectional view, taken on the line 3-3 of Figure 2, showing inter-engaging formations of adjacent screening members of the screen; and FIGURES 4 and 5 are views showing alternative arrangements of inter-engaging formations.

The machine tool shown in Figure 1 is specifically a horizontal milling machine, comprising a machine bed 2, a cutting head (not shown) mounted for rotation about a horizontal axis above the bed, and a workpiece support 6, which is horizontally slidable in a track 4 of the machine and to which a workpiece 8 is secured.

The machine comprises a screen which is operative around the four sides thereof, two of which sides being shown in Figure 1. The screen comprises an elongate mounting member 12 for each of the four sides, and a plurality of elongate screening members 14 secured to each mounting member 12 as cantilvers therefrom.

Each screening member is moulded from a clear thermoplastics material, in particular a polycarbonate plastics material, and is provided on its longitudinal side edges with tongue and groove formations 16,18. Extending longitudinallyofthe mounting member is a central, elongate slot 20.

Provided in each mounting member 12 are threaded bores 22, the spacing between which is equal to the width of the screening members, allowing for the tongue and groove formations thereof.

For each mounting member 12 the screen comprises a securing member 24 comprising a threaded portion 26 adapted to be screwed into the bores 22, a boss portion 28 of greater diameter than that of the threaded portions 26, and a knob 30. By screwing the threaded portion 26 into the bore 22, the securing member may be movable from an inoperative to an operative condition, a clamping member 32 on the threaded portion being urged by the boss into gripping engagement with the screening member, clamping the screening member to the mounting member and preventing movement of the screening member relative to the mounting member.

The mounting member 12 also comprises means, afforded by bores 34 at the end thereof, and bolts 36, to enable the mounting memberto be secured to an adjacent mounting member of the screen, for example one extending therefrom at right angles thereto, as is shown in Figure 1.

In the use of the screen which is the preferred embodiment of this invention, the screening mem bers may be clamped to the mounting member, generally as is shown in Figure 2, and represents part of the screen for the front of the machine, as viewed in Figure 1. In the preferred embodiment, the screen is adapted to rest on the bed 2 of the machine tool, by engagement therewith of some of the screening members 14. However if desired, one or more of the mounting members 14 may alternatively or additionally be secured to part of the machine tool, either directly to a fixed part thereof or indirectly, such as by the use of brackets.

By loosening one or more of the securing members 24 (i.e. moving them to their inoperative conditions), one or more of the screening members may be moved transversely of the mounting member, in the directions A or B shown in Figure 2, into desired positions relative to the machine bed, the cooperation between the inter-engaging formation of such a screening member with that of an adjacent, fixed member, as is retained during and on completion of such adjusting movement, ensuring stability of the screen as a whole.

In this manner, individual screening members may be adjusted longitudinally thereof, viz, transversely of the mounting member, so as to afford an aperture above the machine bed, as is required to permit a workpiece to move and from the area being screened, as is shown on the righthand side in Figure 1. When the workpiece is changed, the screening members above the machine bed may be readily positionally adjusted, to provide a changed aperture corresponding to profile of the new workpiece.

Additionally, where the circumstances require, by loosening the securing members of all the screening members on one side of the screen, all the screening members may be tilted a small amountaboutthe axis of their respective bores 22, as may be desired.

The inter-engaging tongue and groove formations of the screening members of the preferred embodi mentofthisinvention is shown in detail in Figire 3, a tongue 16 on one screening member engaging into a groove 18 on an adjacent screening member. Each screening member may be provided with both a tongue on one longitudinal edge and a groove on the opposite longitudinal edge, or alternate screening members may be provided with tongues on both longitudinal edges, or grooves on both longitudinal edges.

As an alternative to the screening members affording their support by direct inter-engagement therebetween, elongate supporting members 38 may be utilised, which may be secured to act between adjacent longitudinal side edges of adjacent screening members, asis shown in Figure 4. Such a supporting member 38 may be fixedly secured to one screening member, such as that indicated at 14a in Figure 4, being slidable relative to the adjacent screening member 14b.

Whilst in both of the embodiments illustrated in Figures 3 and 4, support is provided for the screening members which is operative in both directions transversely thereto (indicated by the arrows C and D in Figure 3) and support of such an extent is indeed desirable, it is within the scope of this invention to utilise a supporting means, such as that illustrated in Figure 5, which is operative to provide support of one screening member by an adjacent screening member in one direction only transversely thereto.

Thus as is shown in Figure 5, the screening member 14b provides for support exerted on screening member 14a in the direction of the arrow C but not in the direction of the arrow D, whilst the screening member 14a provides support for the screening member in the direction of the arrow D, but not in the direction of the arrow C.

Claims (19)

1. A screen for a machine tool and comprising an elongate mounting member, a plurality of elongate screening members, and securing means by which the screening members may be mounted on the mounting member, the securing means being movable between an inoperative condition in which one or more screening member may be moved longitudinally thereof relative to the mounting number and an operative condition in which such securing member is secured to the mounting member.

2. A screen according to Claim 1 comprising supporting means which is operative between adjacent screening members to provide for mutual support whilst permitting relative longitudinal movement therebetween.

3. A screen according to one of Claims 1 and 2 wherein the mounting member is adapted to be secured to a fixed part of the machine tool.

4. A screen according to one of Claims 1 and 2 wherein the screen is adapted to rest on part of the machine tool.

5. A screen according to any one of the preceding claims comprising two mounting members secured together, each of said mounting members supporting a plurality of elongate screening members.

6. A screen according to any one of the preceding claims wherein the screening members are adapted to be secured to the mounting member by a collectively-operable securing means, whereby on release of the securing means all the screening members may be positionally adjusted in relation to the mounting member and to one another.

7. A screen according to any one of Claims 1 to 5 wherein each screening member is secured to the mounting member by an individually-operable securing means, whereby any one screening member may be positionally adjusted in relation to the mounting member and to the other screening members whilst said other screening members are retained in fixed positions relative to the mounting member.

8. A screen according to any one of Claims 1 to 5 comprising a plurality of securing means, each being operable collectively to secure some of adjacent screening members to the mounting member.

9. A screen according to any preceding claim as appendantto Claim 2 wherein the supporting means is afforded by formations on the longitudinal side edges of each of the screening members which are adapted to co-act with formations on the longitudi nal side edges of adjacent screening members.

10. A screen according to Claim 8 wherein the formations are such as to enter simple overlapping engagement

11. A screen according to Claim 8 wherein the formations are such as to enter into interfitting engagement.

12. A screen according to Claim 11 wherein the formations are tongue and groove formations.

13. A screen according to any one of Claims 2 to 8 comprising elongate support members adapted to act between adjacent longitudinal side edges of adjacent screening members, to transmit load and hence provide support between one screening memberto an adjacent screening member.

14. A screen according to any one of the preceding claims wherein the screening members are secured as cantilevers to the mounting member.

15. A screen according to any one of the preceding claims wherein the screening members are of plastics material.

16. A screen according to any one of the preceding claims wherein the screening members are transparent or opaque.

17. A screen for a machine tool and comprising an elongate mounting member, and a plurality of elongate screening members releasably secured to and extending transversely of the mounting member, supporting means being provided which is operative between adjacent screening members to provide for mutual support whilst permitting relative longitudinal movementtherebetween.

18. A screen for a machine tool, constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

19. Any novel feature or novel combination of features hereinbefore described and/or shown in the accompanying drawings.