AU2008207607B2 - A guard - Google Patents

Abstract

A guard is disclosed which is arranged for use with a machine, the guard comprising a guard member which is movable between first and second positions, in the first position the guard member being configured to obstruct access to a moving part of the machine and in the second position the moving part is accessible by a machine operator, wherein in use the guard member is permanently attached to the machine. Figure 2 Figure 2

Description

AUSTRALIAN COMPLETE PATENT SPECIFICATION Title: A Guard Applicant: Weir Minerals Australia Limited Inventors: Peter WELLS Jarrad LUMBEWE Stephen BARNETT Alexis PILOTELLE 2 A GUARD Technical Field 5 This invention relates to guards used with machines to prevent injury to operators of the machinery. The invention has particular application to rotary pumps. 10 Background to the Invention Operators of machines face the risk of injury by coming into contact with moving parts of the machine. For instance, if the hair or clothing of a machine operator were to become entangled with a moving part such as a rotating shaft, then the hair or 15 clothing of the operator may quickly become quickly wrapped around the shaft and the operator can be quickly dragged towards and into contact with moving parts of the machine, which can give rise to very serious injuries. This risk exists during normal operation of the machine and whilst making maintenance inspections or adjustments. To reduce the risk of injury to machine operators or maintenance workers, a 20 machine may be fitted with guards which obstruct access to moving parts. This can present an inconvenience to machine operators or maintenance workers, as sometimes it is necessary to remove the guard to carry out routine inspections or maintenance. Unfortunately, it has been found that in practice some guards are sometimes not refitted after removal, and consequently the protection offered by the guard is then lost and the 25 risk of injury during the future operation of the machine is increased. Summary of the Invention 30 In a first aspect the present invention provides a guard arranged for use with a machine, the guard comprising a guard member which is movable between first and second positions, in the first position the guard member being configured to obstruct access to a moving part of the machine and in the second position the moving part is accessible by a machine operator, wherein in use the guard member is permanently 35 attached to the machine. Throughout this specification when the phrase "permanently attached" is used it is intended to mean that the guard member is not separated from the machine under 3 normal operating conditions. Thus, the guard member remains associated with the machine at all times by way of some sort of attachment, and remains so attached until removal by the use of extreme manual force, or by use of a special tool. However, these situations are not considered to be normal operating conditions. 5 Throughout this specification when the phrase "obstruct access" is used it is intended to mean that the guard is configured to be suitable for blocking the access of a limb, finger, hair or other body part of an operator, or an article of clothing from being in contact with a moving part of the machine under normal operating conditions. While it is envisaged that in some instances such contact could be deliberate, for example by 10 jamming a finger through or around the guard, these instances would not be considered to be normal operating conditions. In one embodiment, the guard member may be pivotally moveable between the first and second positions. In one form of this embodiment, the guard member may pivot about a hinge. In 15 one arrangement, the hinge may include a pivot pin. In other forms, rather than by pivoting, the guard member can be attached in other ways, such as by a sliding arrangement, a linkage arrangement, or by being attached by flexible cable or other tethering means. In one embodiment, the guard may further include a removable guard element. 20 In one embodiment, movement of the guard member away from the first position may permit removal of the guard element. In one form of this embodiment, the guard element may be retained by a latch which becomes accessible after the first guard member has moved away from the first position. 25 In any one of these embodiments, the guard member may be retained in the first position by way of a mounting. In one form, this mounting can be a hole which in use receives a fastener. In any one of these embodiments, the guard may include a recess to accommodate a hose fitting and/or access to a grease nipple. 30 In one embodiment the guard further includes means for selectively obstructing the recess. In any one of these embodiments, the guard may be provided with a region of compressible material, the compressible material being compressed when the guard member is in the first position. 35 In any one of these embodiments, the guard may include sections formed from a mesh material. In a second aspect the present invention provides a method of retro -fitting a 4 guard to a rotary machine including the steps of: providing a guard according to the first aspect of the invention; and permanently attaching the guard member in relation to the machine so that the guard can be moveable both to obstruct access to a moving part of the machine by a machine operator and to permit access to a moving part of the 5 machine by that operator. In a third aspect the present invention provides a machine including a guard according to the first aspect of the invention. 10 Brief Description of the Drawings An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a partially assembled pump fitted with a 15 guard member according to an embodiment of the invention; Figure 2 is a detail exploded view of a hinge mounting of the guard member of figure 1; Figure 3 is a detail exploded view of a second mounting of the guard member of figure 1; 20 Figure 4 shows the partially assembled pump of figure 1 with the guard member in the second position; Figure 5 is a reverse view of the pump of figure 1, having been further disassembled to remove the pump casing, this figure showing the guard member in the first position, and guard element. 25 Figure 6 shows the pump of figure 5 with the guard member in the second position; Figures 7 and 8 illustrate the procedure for removal of the guard element; and Figures 9 and 10 illustrate an alternative embodiment of a guard. 30 Detailed Description of the Preferred Embodiment Referring to figure 1, a partially assembled machine is shown in the form of rotary pump 10. A shaft 16 is rotatable within bearing cartridge 7 which is cradled by 35 the pump base 18. The pump 10 when fully assembled includes an impeller (not shown) mounted on the end of shaft 16 and located inside the outer casing 14. When fully assembled a further outer casing piece is mounted to casing 14 to contain the 5 impeller therebetween. At the junction between outer casing 14 and shaft 16, a gland seal (not shown) is employed to control leakage of fluid from inside the pump. In the drawings, the pump 10 is shown fitted with a guard 11. The guard 11 is fitted to the pump 10 in the region generally known as the sealing area, where the outer 5 casing 14 and the shaft 16 meet. The guard 11 includes a guard member 12 which is shown in its first position wherein it obstructs access by a machine operator to the gland seal, to reduce risk of injury. The guard member 12 is formed from a cast steel frame 13 which is generally semicircular in cross-section and to which steel mesh portions 15 are affixed, for example by welding, to create an enclosed space. These mesh portions 10 allow fluid that may leak or spray out of the gland seal to escape from the guard. A recess 17 is provided to allow access for a hose which fits to gland seal to supply the gland seal with pressurised water during pump operation. Referring to figure 2, the guard member 12 is permanently attached to the pump 10 by way of a mounting in the form of hinge 19 which includes a pivot pin 20 15 which passes through apertures in both bracket 21 and guard 12 and is retained in bracket 21 by way of a circlip 23. Referring to figure 3, the guard member 12 is retained in its in use position by way of another mounting which takes the form of a hole 25 in first guard member 12. To retain guard member 12 in the in use position for obstructing operator access to the 20 sealing area, a threaded fastener in the form of bolt 27 is passed through hole 25 and is received in a threaded bush which is mounted in a hole in outer casing 14. During operation of the pump, it is necessary to gain access to the gland seal to tighten the seal and/or to inspect it for wear at regular intervals, typically once per week. To gain access, the guard member 12 is moved to a second position as shown in 25 figure 4. To move the guard into the second position, bolt 27 is first removed and then guard member 12 is moved to the second position by rotating guard member 12 about hinge mounting 19. In the second position, a machine operator may gain access to the gland seal to make any inspection and adjustments required. The guard 11 further includes a guard element in the form of an arcuate mesh 30 strip 30, the operation of which will now be described. Referring to figure 5, the partially assembled pump 10 is shown from the reverse side and with outer casing 14 removed. The gland seal is also not shown. In use, gland seal is fitted between casing 14 and shaft 16 and seals about the shaft at sealing portion 24. The arcuate mesh strip 30 is shown positioned below the guard member 12. In use, arcuate mesh strip 30 35 obstructs access by an operator in the region of the underside of the rotating shaft 16. The arcuate mesh strip 30 is retained in place at one end by a latch 32 and at the other end by a flange 34 which is maintained in position by being pressed down 6 upon by the guard member 12. The guard member 12 is fitted with a region of resilient material in the form of resilient rubber feet 36 to maintain downward pressure on the flange 34 and to reduce rattling caused by vibration during pump operation. Referring to figure 6, the guard member 12 is shown in a second position to 5 permit access by an operator to the general region where the outer casing 14 and the shaft 16 meet. In this position, removal of the arcuate mesh strip 30 is permitted as latch 32 is now accessible to be released by a user. Referring to figure 7, the latch 32 has been released allowing the latch end of arcuate mesh strip 30 to drop downwards. This movement also brings flange 34 away from engagement with pump base 18 thus 10 allowing the arcuate mesh strip 30 to be removed sideways from the machine (see figure 8). Following any necessary inspection or adjustment, the above steps are carried out in reverse to refit the guard. The arcuate mesh strip 30 is refitted and the latch 32 is reattached. The first guard member is rotated back to its first position and the bolt 27 is 15 screwed tight. In some arrangements, the arcuate mesh strip can have a cut away section through which a hose can be passed. The hose can be used for conveying water or air as needed during the operation of the pump. It can be seen that, at all times, the guard member 12 remains permanently 20 mounted to the machine. By its arrangement, the guard cannot be removed from the machine and so assists in maximising the protection afforded to machine operators. All of the parts of the guard 11 can be retrofitted to existing pumps in operation in the field, or installed on new pumps at the time of manufacture. In this specification, the phrase "permanently attached" is intended to mean 25 that the guard member is not separated from the machine under normal operating conditions. Thus, the guard member remains associated with the machine at all times. It is acknowledged that the guard member in the embodiment above could be removed by use of extreme force, or by use of a special tool to remove circlip 23 and pivot pin 20. However, these situations are not considered to be normal operating conditions. 30 Referring to figures 9 and 10, an alternative embodiment of a guard member 112 is shown. This embodiment differs to that described above in two respects. Firstly, pivot pin 20 is omitted and instead the hinge mounting is formed by cylindrical lugs 120 and 122 which sit in apertures in bracket 21 and the guard is retained in place by way of a circlip which engages with a groove provided about lug 122 (see figure 10). 35 Secondly, guard 112 includes means for selectively obstructing the recess 117 in the form of two bolts 125 which are fitted through apertures in the guard. As described for the first embodiment above, the function of the recess 117 is to allow a 7 hose to be fitted to the gland seal that, in use, is found inside the area protected by the guard. In cases where no water supply for the gland seal is required, and hence no hose is required, bolts 125 are fitted to the guard member 112 to obstruct access through the recess. Thus the hand or fingers of a user cannot pass through the recess 117 to prevent 5 injury. In applications where a water hose is to be used, the bolts 125 are removed. In this case the hose itself blocks the recess 117 in use. In the embodiments described above, the guard member was permanently attached to the machine by way of a hinge mounting. Similarly, the guard member could be attached in other ways such as by a sliding arrangement, a linkage 10 arrangement, or be being attached by flexible cable or other tethering means. Any reference to prior art contained herein is not to be taken as an admission that the information is common general knowledge, unless otherwise indicated. Finally, it is to be appreciated that various alterations or additions may be made to the parts previously described without departing from the spirit or ambit of the 15 present invention.

Claims (14)

1. A pump fitted with a guard, the guard comprising a guard member which is movable between first and second positions, in the first position the guard member being configured to obstruct access to a moving part of the machine and in the second position the moving part is accessible by a machine operator, wherein in use the guard member is permanently attached to the machine; the guard further includes a removable guard element and wherein movement of the guard member away from the first position permits removal of the guard element.

2. A pump according to claim 1, wherein the guard member is pivotally moveable between the first and second positions.

3. A pump according to claim 2, wherein the guard member pivots about a hinge.

4. A pump according to claim 3, wherein the hinge includes a pivot pin.

5. A pump according to claim 1, wherein the guard element is retained by a latch which becomes accessible after the guard member has moved away from the first position.

6. A pump according to any one of the preceding claims, wherein the guard member is retained in the first position by way of a mounting.

7. A pump according to claim 6, wherein the mounting is a hole which in use receives a fastener.

8. A pump according to any one of the preceding claims, wherein the guard includes a recess to accommodate a hose fitting and/or access to a grease nipple.

9. A pump according to claim 8, wherein the guard further includes means for selectively obstructing the recess.

10. A pump according to any one of the preceding claims, wherein a region of compressible material is provided, the compressible material being compressed when the guard member is in the first position.

11. A pump according to any of the preceding claims, wherein the guard includes sections formed from a mesh material.

12. A method of retro-fitting a guard to a pump including the steps of. providing a guard; and permanently attaching the guard to the pump so that the pump accords with any one of claims 1 to 11.

13. A pump substantially as herein described with reference to the accompanying drawings.

14. A method substantially as herein described with reference to the accompanying drawings.