GB1583032A

GB1583032A - Machine guards

Info

Publication number: GB1583032A
Application number: GB3853976A
Authority: GB
Original assignee: SILVAFLAME CO Ltd
Current assignee: SILVAFLAME CO Ltd
Priority date: 1977-10-28
Filing date: 1977-10-28
Publication date: 1981-01-21

Description

(54) IMPROVEMENTS RELATING TO MACHINE GUARDS (71) We, THE SILVAFLAME COMPANY LIMITED, a British Company of British Lion Works, Forest Lane, Walsall, West Midlands, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement:- The present invention relates to machine guards.

The invention has been developed primarily for application to machine guards mounted or adapted for mounting on machines in which access to the working station to be guarded is under the control of the operator as distinct from being controlled or restricted by interconnection with working parts of the machine, the guard also providing a barrier to prevent particles, for example, from a workpiece coming into contact with an operator. Such guards are often employed when the machine is of a type in which a wide variety of working operations can be performed by the tool or tools the machine involving the use of space (for motion of the tool or tools) differing appreciably as between one operation and another. To satisfy the requirements such guards may comprise a plurality of members, hereinafter referred to as guard members, adapted for mounting in different configurations around at least part of the boundary of the working station so that each such guard member is in an operative (operator protecting) position, one at least of the guard members being movable by the operator between an operative position and an inoperative position in which access to the machine is permitted, being the part of the barrier provided by the said one guard member being removed.

According to the present invention we provide a machine guard comprising at least two guard members pivotally connected one to the other, each guard member in cluding a portion adjacent the pivotal axis which has a plurality of locking formations angularly spaced around said axis, the associated pivotally connected guard member having a complementary locking formation engageable selectively with any one of the first said locking formations, and a mounting means adapted to be connected to at least one of said guard members and operative to support said machine guard on or adjacent a machine.

Preferably each of said guard members comprises a frame and a panel of transparent material mounted in the aperture afforded by the frame.

Each of said pivotally connected guard members may be of substantially planar form, these members having dimensions parallel to the pivotal axis equal to each other. Preferably also the dimensions of these members at right angles to the pivotal axis are equal to each other.

The invention is further concerned with mounting means which may be used as the mounting means for the machine guard in accordance with this invention.

The mounting means comprises elongate members (hereinafter called "rods") for installation between the machine guard and a machine, clamping means for securing the rods to each other in any one of a number of relative angular positions, such clamping means including a tie member on which are mounted a plurality of clamping members one pair of which has a first pair of mutually adjacent faces defining a passageway for reception of one of the rods and a second pair which have a second pair of mutually adjacent faces defining a passageway for another of the rods, further clamping member faces which are adjacent to each other, one on a clamping member of the first pair and the other on a clamping member of the second pair being respectively provided with means for positively locating the two last said clamping members relative to each other against angular movement about the axis of the tie member, and tightening means for exerting the requisite clamping force axially of the tie member.

Preferably the passageways and the rods are of non-circular cross-section such that each rod may be positively located against angular movement about its own axis rela tively to the pair of clamping members between which it is held, and in any one of a plurality of angular positions.

The tie member and one at least of the clamping members may have cooperative locating formations for positively locating these members against relative angular movement about the axis of the tie member.

Thus, in one arrangement, the locating formation on the tie member may be a head adjacent to one end of the tie member, and the locating formation on the clamping member may be a recess in which the head is held non-rotatably.

The means for positively locating adjacent clamping members one in the first pair and the other in the second pair against relative angular movement as aforesaid, may comprise cooperative formations in the form of a recess and a projection held non-rotatably in the recess. One advantageous arrangement is that the recesses, which may be substantially identical in form to that in which the head of the member is received, may be provided in each of the clamping members and the projection may be a bush held nonrotatably in one of these recesses and projecting therefrom into the other of the recesses in which it is also held non-rotatably.

A convenient form of recess is one having angularly spaced teeth or splines in its peripheral face and the head and projection may be of hexagonal or other polygonal form which apices engage between adjacent teeth or splines. Thus each clamping member may be made of substantially identical form.

One embodiment of the present invention will now be described in detail by way of example only with reference to the accompanying drawings wherein: FIGURE 1 is an illustration of a machine guard and mounting means according to the present invention, FIGURE 2 is an exploded view of part of the mounting means shown in Figure 1.

The machine guard illustrated comprises two guard members shown generally at 10 and 11 which are identical in construction and therefore only one of which will be described in detail. The guard member 11 comprises a frame made from an alloy diecasting having an upper part 12, a lower part 13, an interconnecting side part 14, another interconnecting side part 15. Into the frame is secured a sheet of transparent plastics material 16. The mounting of the panel into the frame is such that if any panel becomes damaged it may be removed and replaced by a new one.

The upper edge 12 of the frame 11 is provided at one end with a planar segment 17 having a plurality of through bores 18 extending around the circumference and a further through bore 19 through which a fastening member 20 extends to secure the guard member 11 to another guard member or, in this case, the mounting bracket 21.

The other end of the upper edge 12 is provided with a boss 22 having a through bore 23.

The configuration of the boss 22 can be seen better from the equivalent corner of the guard member 10. Also provided at that end of the upper edge 12 is a further through bore illustrated at 24 on the guard member 10 through which the securing member 25 may pass. A corresponding through bore will be provided on the segment 26 and a fastener will pass therethrough and through a through bore at the lower left-hand corner of the frame 13 in order to secure members 10 and 11 in pivotal relationship.

Adjacent the lower left-hand corner of the frame 13 is provided a boss 27 having a through bore therein identical to the boss 22. A spring loaded plunger having a manually engageable part 28 is located therein.

The spring loaded plunger can be better seen in the lower left-hand corner of the guard member 10.

The downwardly depending part 29 locates in any one of the plurality of through bores 30 provided in the segment in the lower right-hand corner of each guard member. It will be appreciated that the boss 27 is identical with the boss 22 located in the top left-hand corner of the frame 13 and if required a similar spring loaded plunger can be mounted in the boss 22 in order to give relative angular locking between the two frames 10 and 11 both at the top and at the bottom. Alternatively, if only one of the spring loaded plungers is required it may be provided either at the top or the bottom of the frame, and the vacant boss may be provided with additional detachable securing means such as a nut and bolt, the bolt passing through both the throughbore in the boss and any one of the throughbores in the segment in order to prevent undesired relative angular movement between two adjacent pivotally connected frames from a desired angularly aligned position.

To release the spring loaded plunger, the manually engageable part 28 is pulled upwardly and the downwardly depending part as shown at 29 of the guard member 10 comes out of engagement with the through bores 30 in the segment. The guard member 10 can then be pivoted relative to the guard member 11 and, when the desired relative angular position has been reached, the manually engageable part 28 is released, the spring loaded plunger taking up its locking position in one of the through bores 30 under the action of the spring mounted therein.

The mounting means on which the guard member is mounted will now be described in more detail.

A clamping member 35 in the form of a disc (and hereinafter referred to as "a disc") is placed adjacent to the bracket 21. It is provided with a multi-sided recess in the face adjacent the bracket 21 in which is positioned a bush, the bush having a through bore, which is square in cross-section, the size of the square being approximately the same as the size of the square-shaped crosssection of the through bore.

A bolt (not visible) having a square in cross-section shank part adjacent its head passes through one of the through bores 36 in the mounting bracket 21 and through the first disc 35, this part of the shank co-operating with the square section through bore in the bush to prevent rotation of the disc 35 with respect to the mounting bracket 21. A further disc 37 is then placed over the bolt and a handle member 38 incorporating a nut engaged on the helical thread of the bolt. As the handle 38 is rotated the two discs 35 and 37 are moved towards each other, and clamp the hexagonal section rod 39 therebetween. The mutually adjacent faces of the discs 35 and 37 are each provided with a groove so that a rod receiving passageway is provided. The groove may be multi-sided to co-operate with the hexagonal section of the rod 39.

The handle member 38 may be spring loaded into driving engagement with the nut such that if the handle 38 is pulled in an outwardly axial direction it may be rotated without rotating the nut. For example, the nut may be provided with a splined outer surface and the handle member 38 may be provided with a splined inner surface to engage the nut.

At a position along the rod 39 spaced from the mounting bracket 21 the rod is secured in a mounting means which comprises a tie member in the form of a bolt 40, clamping members 41-44 in the form of discs and hereinafter referred to as "discs", washer 45 and handle member 46. A bush is provided between discs 42 and 43 and has its apices engaged within grooves formed between the teeth provided on the side wall of the recesses formed in the mutually adjacent faces of each of these discs.

Each of the discs 41 to 44 and the discs 35 and 37 may be of identical form. Each disc being provided with a recess in one face, the recess having a toothed or splined side wall, as seen at 47 on the disc 44, the other face of the disc being provided with a groove 48. This groove may be non-circular of cross-sectional form in order to cooperate closely with whatever section of rod it is required to clamp and the projecting spacer part 49 which compensates for the thickness of the rod to be clamped between two adjacent discs to keep the clamping discs approximately parallel.

In use all four discs 41 to 44 are located in position on the bolt 40. The head of the bolt 40 locates itself in the multi-sided recess in the outer face of the outer disc 41.

The rod member 50 is positioned in the grooves provided on the cooperating faces of the discs 41 and 42. A multi-sided bush locates the angular position of disc 42 with respect to the disc 43 which is located in each of the toothed or splined recesses in the cooperating faces of these discs. Thus angular relationship between the disc 42 and the disc 43 may be altered in a plurality of discrete steps. The rod 39 is positioned between discs 43 and 44 and finally a washer 45 and handle 46 having a captive nut member is placed in position and rotated with respect to the bolt 40. The rods 39 and 50 are thus securely clamped by the discs 41-44. The handle member 46 is similar in construction to the handle member 38 and may be resiliently biased into a position of engagement with the nut member.

In view of the great number of different possible angular positions between the rod 50 and the rod 39, and the rod 39 and the mounting bracket 21, the mounting means of the machine guard enables the guard to be set at almost any angle relative to the part of the machine to which the end of the rod 50 is secured, or alternatively with respect to a foot provided on the end of the rod 50 as the case may be.

It will be appreciated that whereas only two guard members 10 and 11 are shown illustrated in the accompanying drawing, any number of members may be provided and they may be of identical construction and size, or alternatively may be of varying widths but are all preferably of the same height.

The frames of the machine guards may alternatively be made from a plastics material and in particular may be made from a glass reinforced plastics material, and may be made by any suitable process such as injection moulding.

WHAT WE CLAIM IS: 1. A machine guard comprising at least two guard members pivotally connected one to the other, each guard member including a portion adjacent the pivotal axis which has a plurality of locking formations angularly spaced around said axis, the associated pivotally connected guard member having a complementary locking formation engageable selectively with any one of the first said locking formations, and a mounting means adapted to be connected to at least one of said guard members and operative to support said machine guard on or adjacent a machine.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. A clamping member 35 in the form of a disc (and hereinafter referred to as "a disc") is placed adjacent to the bracket 21. It is provided with a multi-sided recess in the face adjacent the bracket 21 in which is positioned a bush, the bush having a through bore, which is square in cross-section, the size of the square being approximately the same as the size of the square-shaped crosssection of the through bore. A bolt (not visible) having a square in cross-section shank part adjacent its head passes through one of the through bores 36 in the mounting bracket 21 and through the first disc 35, this part of the shank co-operating with the square section through bore in the bush to prevent rotation of the disc 35 with respect to the mounting bracket 21. A further disc 37 is then placed over the bolt and a handle member 38 incorporating a nut engaged on the helical thread of the bolt. As the handle 38 is rotated the two discs 35 and 37 are moved towards each other, and clamp the hexagonal section rod 39 therebetween. The mutually adjacent faces of the discs 35 and 37 are each provided with a groove so that a rod receiving passageway is provided. The groove may be multi-sided to co-operate with the hexagonal section of the rod 39. The handle member 38 may be spring loaded into driving engagement with the nut such that if the handle 38 is pulled in an outwardly axial direction it may be rotated without rotating the nut. For example, the nut may be provided with a splined outer surface and the handle member 38 may be provided with a splined inner surface to engage the nut. At a position along the rod 39 spaced from the mounting bracket 21 the rod is secured in a mounting means which comprises a tie member in the form of a bolt 40, clamping members 41-44 in the form of discs and hereinafter referred to as "discs", washer 45 and handle member 46. A bush is provided between discs 42 and 43 and has its apices engaged within grooves formed between the teeth provided on the side wall of the recesses formed in the mutually adjacent faces of each of these discs. Each of the discs 41 to 44 and the discs 35 and 37 may be of identical form. Each disc being provided with a recess in one face, the recess having a toothed or splined side wall, as seen at 47 on the disc 44, the other face of the disc being provided with a groove 48. This groove may be non-circular of cross-sectional form in order to cooperate closely with whatever section of rod it is required to clamp and the projecting spacer part 49 which compensates for the thickness of the rod to be clamped between two adjacent discs to keep the clamping discs approximately parallel. In use all four discs 41 to 44 are located in position on the bolt 40. The head of the bolt 40 locates itself in the multi-sided recess in the outer face of the outer disc 41. The rod member 50 is positioned in the grooves provided on the cooperating faces of the discs 41 and 42. A multi-sided bush locates the angular position of disc 42 with respect to the disc 43 which is located in each of the toothed or splined recesses in the cooperating faces of these discs. Thus angular relationship between the disc 42 and the disc 43 may be altered in a plurality of discrete steps. The rod 39 is positioned between discs 43 and 44 and finally a washer 45 and handle 46 having a captive nut member is placed in position and rotated with respect to the bolt 40. The rods 39 and 50 are thus securely clamped by the discs 41-44. The handle member 46 is similar in construction to the handle member 38 and may be resiliently biased into a position of engagement with the nut member. In view of the great number of different possible angular positions between the rod 50 and the rod 39, and the rod 39 and the mounting bracket 21, the mounting means of the machine guard enables the guard to be set at almost any angle relative to the part of the machine to which the end of the rod 50 is secured, or alternatively with respect to a foot provided on the end of the rod 50 as the case may be. It will be appreciated that whereas only two guard members 10 and 11 are shown illustrated in the accompanying drawing, any number of members may be provided and they may be of identical construction and size, or alternatively may be of varying widths but are all preferably of the same height. The frames of the machine guards may alternatively be made from a plastics material and in particular may be made from a glass reinforced plastics material, and may be made by any suitable process such as injection moulding. WHAT WE CLAIM IS:

1. A machine guard comprising at least two guard members pivotally connected one to the other, each guard member including a portion adjacent the pivotal axis which has a plurality of locking formations angularly spaced around said axis, the associated pivotally connected guard member having a complementary locking formation engageable selectively with any one of the first said locking formations, and a mounting means adapted to be connected to at least one of said guard members and operative to support said machine guard on or adjacent a machine.

2. A machine guard as claimed in Claim

1 wherein the first said formations comprise indentations or holes formed in or through the said portion and said complementary locking formation comprises a part engageable in said indentations or holes.

3. A machine guard as claimed in Claim 2, wherein said complementary locking formation comprises a plunger having a manually engageable part, a further part engageable in said indentations or holes, and wherein spring means are provided for biasing the plunger into a securing position.

4. A machine guard as claimed in any one of the preceding claims wherein the mounting means comprises elongate members (hereinafter called "rods") for installation between the machine guard and a machine, clamping means for securing the rods to each other in any one of a number of relative angular positions, said clamping means including a tie member on which are mounted a plurality of clamping members.

one pair of which has a first pair of mutually adjacent faces defining a passageway for reception of one of the rods and a second pair which have a second pair of mutually adjacent faces defining a passageway for another of the rods, further clamping member faces which are adjacent to each other, one on a clamping member of the first pair and the other on a clamping member of the second pair being respectively provided with means for positively locating the two last said clamping members relative to each other against angular movement about the axis of the tie member. and tightening means for exerting the requisite clamping force axially of the tie member.

5. A machine guard as claimed in claim 4 wherein the passageways and the rods are of non-circular cross-section such that under the action of the tightening means each rod is positively located against angular movement about its own axis relatively to the pair of clamping members between which it is held, and in any one of a plurality of angular positions.

6. A machine guard as claimed in claim 4 or 5 wherein the tie member and at least one of the said clamping members have cooperating locating formations for positively locating these members against relative angular movement about the axis of the tie member.

7. A machine guard as claimed in claim 6 wherein the locating formation on the tie member comprises a head adjacent to at least one end of the tie member, and the locating formation on the clamping member comprises a recess which head engages nonrotatably.

8. A machine guard as claimed in any one of claims 4 to 7 wherein the means of positively locating the adjacent clamping members one in the first pair, and one in the second pair, against relative angular movement comprises cooperative formations in the form of a recess, and a projection engaging non-rotatably in the recess.

9. A machine guard as claimed in claim 8 wherein each of said adjacent clamping members of the first and second pairs respectively is provided with a recess, and the projection comprises a bush engaging nonrotatably in one of these recesses from which it projects, and engaging non-rotatably in the other recess.

10. A machine guard as claimed in claims 8 or 9 wherein the or each of the recesses is provided with angularly spaced teeth or splines in its peripheral face, and the projection is of hexagonal or other polygonal form presenting apices which engage between adjacent teeth or splines.

11. A machine guard as claimed in any one of claims 8 to 10 wherein said projection has a cross-sectional shape in a plane at right angles to the axis of the tie member and which is the same as that of the head of the tie member.

12. A machine guard as claimed in any one of claims 4 to 11 wherein the tightening means comprises a head at one end of the tie member and a handle part engaging with the end portion of the tie member adjacent to its other end through cooperative screw thread formations on the tie member and handle part.

13. A machine guard as claimed in claim 12 wherein the screw thread formation of the handle part is formed on a captive nut in or on the handle part.

14. A machine guard as claimed in claim 13 wherein the handle member is spring loaded into driving engagement with the captive nut in a manner such as to permit the handle part to be released manually against the spring from driving engagement with the nut for rotation of the handle with out operation of the tightening means.

15. A machine guard substantially as hereinbefore described with reference to and as illustrated in Figure 1.

16. A machine guard as claimed in any one of the preceding claims including mounting means substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2.