GB2418000A

GB2418000A - Mounting apparatus for mounting a power unit on a body and method

Info

Publication number: GB2418000A
Application number: GB0518248A
Authority: GB
Inventors: Jamie Hamilton
Original assignee: BELLE ENGINEERING
Current assignee: BELLE ENGINEERING
Priority date: 2004-09-13
Filing date: 2005-09-07
Publication date: 2006-03-15
Anticipated expiration: 2025-09-07
Also published as: GB2418000B; GB0919204D0; GB2461826A; GB2461826B; GB0518248D0; GB0420360D0; GB2461826B8

Abstract

A mounting apparatus for mounting a power unit 14 on a main body section 2 to drive a work tool using a drive belt arrangement 8. The mounting apparatus comprises a first section 16 on which a power unit 14 is mountable and a second section 22 attachable to a main body section 2. a number of anti-vibration mounts 18 are locatable between the first and second sections 16, 22 to absorb vibration caused by the power unit 14. A further anti-vibration mount 24 is mounted under compression between the first section 16 and the second section 22 and arranged such that its restorative force substantially offsets tension in a drive belt arrangement 8 acting to tilt the power unit 14 in use. A handle arrangement for attachment to a work tool is also disclosed in which two pairs of anti-vibration mounts connected between first and second sections of the arrangement which inhibit the transfer of vibrational movement between the sections.

Description

24 1 8000 Mountina Apparatus and Method The present invention relates to a

mounting apparatus, for example for mounting a power unit on a main body section to drive a work tool, a method for mounting a power unit on a main body section to drive a work tool and an apparatus comprising such a mounting apparatus, such as a floor grinder and/ a floor saw.

There are a number of applications where it is necessary to operate an apparatus to treat or process a hard surface such as a road surface or a concrete floor in which the tool operating on the surface is rotary and is driven by, for example, an internal combustion engine, usually a small petrol driven motor, which drives the rotary elements. Such machines may experience considerable vibration due to the aggressive nature of the contact with the surface being processed and the engine itself. It is undesirable for this vibration to be transferred to the operator of the apparatus as it may cause health problems and be generally unpleasant to use.

Frequently, in such apparatus, power is transmitted from the drive motor to the tool operating on the work surface by means of a number of belts and pulleys which are driven by the motor. The engine is typically resiliently mounted on the body of the machine by means of a number of anti-vibration mounts. However, in order to transmit the power, the belts must be taut on the pulleys attached to both the engine and the tool. As the engine is resiliently mounted, tension in the belts will tend to tilt the drive shaft of the engine thus causing differing tensions in each of the belts and therefore uneven wear.

Machines such as those described above, for example floor saws or floor grinders, are normally guided and moved by an operator using a handle attached to the body of the apparatus, often in the form of a shaft with a cross piece carrying handle grips for the operator to hold. Vibration from the machine may travel up the handle shaft to the operator. Again, this is undesirable and may have potentially adverse health effects on the operator.

Thus there is a need for an apparatus and method which enables a reduction in the amount of vibration transmitted to the operator of a device such as a floor grinder or a floor saw.

According to a first aspect of the present invention there is provided a mounting apparatus for mounting a power unit on a main body section to drive a work tool using a drive belt arrangement, the mounting apparatus comprising: a first section on which a power unit is mountable; a second section attachable to a main body section; a number of anti-vibration mounts locatable between the first and second sections to absorb vibration caused by the power unit; and a further anti-vibration mount mounted under compression between the first section and the second section and arranged such that its restorative force substantially offsets tension in a drive belt arrangement acting to tilt the power unit in use.

Preferably, the number of anti-vibration mounts is greater than one.

In a preferred embodiment, in use the power unit has a drive shaft, the main body section being attachable in use to a work tool mountable on a further shaft, and wherein the further anti-vibration mount has a longitudinal axis substantially perpendicular to the longitudinal axes of the drive shaft and the further shaft and is arranged such that in use it acts to maintain the longitudinal axis of the drive shaft substantially parallel to the longitudinal axis of the further shaft.

Preferably one or more of the number of vibration mounts are formed of rubber material.

According to a second aspect of the present invention there is provided an apparatus such as a floor saw and/or a floor grinder comprising: a power unit; a main body section; a work tool; and the mounting apparatus defined above for mounting the power unit on the main body section.

According to a third aspect of the present invention there is provided a method for mounting a power unit on a main body section to drive a work tool using a drive belt arrangement, the method comprising the steps: mounting a power unit on a first section; locating a number of antivibration mounts between the first section and a second section to absorb vibration caused by the power unit; and mounting a further anti-vibration mount under compression between the first section and the second section such that its restorative force substantially offsets tension in a drive belt arrangement acting to tilt the power unit in use.

According to a fourth aspect of the present invention there is provided a handle arrangement for attachment to an apparatus in which vibration is generated comprising: a first section having one or more handgrips; a second section connectable in use to the apparatus; a first pair of antivibration mounts connectable between the first and second sections; a second pair of anti-vibration mounts connectable between the first and second sections; wherein the first pair of anti-vibration mounts is arranged at an angle to said second pair of anti-vibration mounts to inhibit vibrational movement from being transmitted from the first section to the second section in more than one plane.

Preferably, each one of the first pair of anti-vibration mounts has an associated longitudinal axis, and wherein the anti-vibration mounts in the first pair are arranged to be coaxial.

In a preferred embodiment, each one of the second pair of anti-vibration mounts has an associated longitudinal axis, and the anti-vibration mounts in the second pair are arranged such that the longitudinal axis of one of the anti- vibration mounts in the second pair is substantially parallel to the longitudinal axis of the other of the anti-vibration mounts in the second pair. Preferably, the first and second pairs of anti-vibration mounts are arranged such that the longitudinal axes of the anti-vibration mounts in the first pair extend in a plane substantially orthogonal to the plane in which the longitudinal axes of the anti- vibration mounts in the second pair extend.

In a preferred embodiment, the first section comprises a housing for housing the first and second pairs of anti-vibration mounts, and the second section may comprise an elongate shaft.

Preferably, the one or more handgrips are formed of a rubber material.

In a preferred embodiment, the handle arrangement further comprises one or more struts attachable, for example by welding, to said second section for attaching the second section in use to the apparatus.

According to a fifth aspect of the present invention there is provided an apparatus such as a floor grinder or a floor saw, in which vibration is generated comprising the handle arrangement defined above.

Preferred embodiments of the present invention will now be described by way of example, and with reference to the accompanying drawings, in which: Figure 1 is a side view of a floor saw according to an embodiment of the invention; Figure 2 is a perspective view from the rear of the saw of Figure 1; Figure 3 is a rear elevation of the mounting apparatus and belt drive of the saw of Figure 1; Figure 4 is a perspective view of the handle of the saw of Figure 1; Figure 5 is a partial perspective view from above and one side of the saw of Figure 1; Figure 6 is a partial perspective view from above and the rear of the saw of Figure 1 showing the mounting apparatus according to a preferred embodiment of the present invention; Figure 7 is a perspective view of the saw of Figure 6 from the front; Figure 8 is a perspective view from the underside of a floor grinder according to a further preferred embodiment of the present invention; Figure 9 is a front elevation of the mounting apparatus of the floor grinder of Figure 8; Figure 10 is an elevation of the grinder of Figure 8; Figure 11 is a perspective view of the handle of the grinder of Figure 8; Figure 12 is a perspective view from the underside of the handle of Figure 11; Figure 13 is a plan view of the underside of the handle of Figure 11; and Figure 14 is a frontal elevation of the handle of Figure 11.

Figures 1 to 7 illustrate a floor saw 1 and components thereof according to a first preferred embodiment of the invention. The floor saw 1 comprises a main body section 2, a saw (not shown) mounted on a shaft 4 carrying a belt pulley 6 at one end. The belt pulley 6 is driven by a number of belts 8 which are driven by a further pulley 10 mounted on a drive shaft 12 of a drive motor 14. The motor 14 is carried on a plate 16 and the plate 16 is attached to the main body section 2 using a number of anti-vibration mounts 18. The plate 16 is bent such that it has a flat surface 20 to which the motor 14 is bolted and two free end sections 21 which are bent downwardly at an angle so that the end sections 21 taper outwardly from the flat section 20 and extend towards the main body section 2. The main body section 2 carries, on its upper surface in the operation condition, a bracket arrangement 22 such that the free end sections 23 of the bracket arrangement 22 are bent upwardly and inwards to be substantially parallel to the free ends 21 of the plate 16.

Each of the number of anti-vibration mounts 18 is located and retained between the free end sections 21 of the plate 16 and the free end sections 23 of the brackets 22. This arrangement enables the motor 14 to move slightly vertically, laterally and longitudinally. The number of anti-vibration mounts 18 may vary according to the apparatus and its use, for example, in the apparatus of figure 1 to 7, four anti-vibration mounts 18 are included.

A further anti-vibration mount 24 is fitted between a further bracket section 25 which may be an extension of one of the free end sections 21 of the plate 16 and a bracket 26 mounted to a side face of the main body section 2.

The floor saw 1 further comprises a pair of wheels 30 located at the rear of the apparatus and attached to the main body section 2.

A handle 32 for use by the operator of the apparatus 1 is mounted on the rear of the apparatus and comprises an elongated shaft 34 and a cross piece 36 carrying a hand grip portion 38.

As shown in Figure 4, the handle 32 further comprises a number of struts 40 which are attachable to the opposite end of the shaft 34 to the end carrying the cross piece 36. One end 41 of each of the struts 40 is couplable to a mounting plate 42 attachable to the rear of the main body section 2. The ends 41 of each strut 40 are spaced from each other laterally and the other ends 43 of the struts 40 are attached to the shaft 34. The shaft 34 may be formed in two parts to allow height adjustment for the operator, the upper section being telescopically receivable in and slidable with respect to the lower section and fixable relative thereto using a clamp 44.

The shaft 34 is attached to a plate 46 carrying two anti-vibration mounts 48 which are connected to the base of an open backed box 50. A further plate 52 is also attached to the shaft 34 and carries two further antivibration mounts 54 which are connected to the sides of the box 50. The crosspiece 36 extends through the sides of the box 50 and carries the two handgrips 38.

The two anti-vibration mounts 54 mounted on sides of box section 50 are coaxial and the two anti-vibration mounts 48 mounted on the base of the box section 50 have longitudinal axes which are substantially parallel to each other. These axes are substantially orthogonal to the longitudinal axis of the two anti-vibration mounts 54 mounted on the side of the box section 50.

In operation, the motor 14 drives the motor shaft 12 and its associated pulley transmitting rotary power to the further pulley 6 on the shaft 4 thus turning the saw (not shown) carried on the shaft 4.

Vibration from the motor 14 is reduced by the anti-vibration mounts 18. The further anti-vibration mount 24 is mounted in compression and, in use, exerts an upward force on the bracket 25 to offset the tilting action due to the tension in the belts 8 thereby keeping the shaft 12 of the motor 14 substantially parallel to the shaft 4 on which the saw is carried thereby evening the tension in the belts 8 and therefore the wear of the belts 8.

Residual vibration from the motor 14 and the saw is transmitted up the shaft 34 and is further reduced by the arrangement of anti-vibration mounts 48 and 54 in the box section 50 carrying the operating handle hand grips 38. The box section 50 carrying the hand grips 38 is connected to the shaft 34 and therefore the rest of the apparatus 1 via the anti-vibration mounts 48 and 54 which absorb vibration from the motor 14 and the saw. Thus the hand grips 38 are resiliently mounted to the body section 2 of the apparatus 1 and the orthogonal arrangement of the anti-vibration mounts 54 and 48 absorbs much of the vibration travailing up the shaft 34 but at the same time mounting of the handle section 32 is rigid enough for the operator to control the apparatus 1.

Figures 8 to 14 show a floor grinder 60 according to a further preferred embodiment of the invention. The floor grinder 60 comprises a main body section 62, a grinder 63 mounted on a shaft 64 carrying a belt pulley 66 at one end. The belt pulley 66 is driven by a number of belts not shown (which are driven by a further pulley 70 mounted on a drive shaft 72 of a drive motor 74.

The drive motor 74 is carried on a plate 76 and the plate is attached to an upper face of the main body section 72 in the in use configuration through a number of anti-vibration mounts 78. The plate 76 is bent such that it has a flat section 80 to which the motor 74 is bolted and two free end sections 81 which are bent downwards at an angle so that the end sections 81 taper outwardly from the flat section 80 and extend towards the main body section 62. The main body section 62 carries a bracket arrangement 82 such that the free end sections 83 of the bracket arrangement 82 are bent upwardly and inwardly to be substantially parallel to the free end sections 81 of the plate 76.

A number of anti-vibration mounts 78 are fitted and retained between the end sections 81 of the plate 76 and the end sections 83 of the bracket arrangement 82. This arrangement enables the motor 74 to move slightly vertically, laterally and longitudinally.

A further anti-vibration mount 84 is fitted between a further bracket section 85 which may be an extension of one of the free end sections 81 of the plate 76 and a bracket 86 mounted to a side face of the main body section 62.

The floor grinder 60 further comprises a pair of wheels 90 located at the rear of the apparatus 60 and is attached to the main body section 62.

A handle 92 for use by the operator of the apparatus 60 is mounted on the rear of the apparatus 60 and comprises an elongated shaft 94 and a cross piece section 96 carrying hand grip portions 98. The handle 92 further comprises a number of struts (not shown) which are attachable to the opposite end of the shaft 94 to the end carrying the cross piece 96 and which are attachable by means (not shown) to the main body section 62.

A boss 100 is welded to the main shaft of the handle and carries two rotatable portions 102 which are rotatable about a longitudinal shaft of the boss, and a clamping device 103 for blocking the rotation of the rotatable portions 102 about the shaft. An arm 104 is attached to each rotating portion 102 and extends radially from the longitudinal shaft. The other end of each arm 104 to that attached to the rotating portions 102 is attached to a respective anti- vibration mount 106 which is retained and attached to the side wall 107 of an open backed box section 110. A strap 112, which may be formed from a material such as metal, connects the two arms 104 and at each end the strap carries a further anti-vibration mount 113 which is retained between the base 114 of the box section 110 and the ends of the strap 112. Thus the axes of the anti-vibration mounts 106 are orthogonal to the axes of the antivibration mounts 108. A pair of arms 116 projecting from an end section of the box section 110 carries a cross piece 118 to which is mounted the pair of hand grips 98.

In use, the user may adjust the height of the handle 92 using the boss 100 and clamping device 103 arrangement.

In operation, the motor 74 drives the motor shaft 72 and its associated pulley transmitting rotary power to the further pulley 66 on the shaft 64 thus turning the grinder 63 mounted thereon. The main purpose of the floor grinder 63 is to reduce surface height by grinding it away and this is achieved by a rotating axle arrangement carrying a plurality of star shaped toothed blades which, when in contact with the floor create a grinding effect thereby reducing the height of the surface.

Vibration from the motor 74 is reduced by the anti-vibration mounts 78. The further anti-vibration mount 84 is mounted in compression and, in use, exerts an upward force on the bracket 85 to offset the tilting action due to the tension in the belts thereby keeping the shaft 72 of the motor 74 substantially parallel to the shaft 64 on which the grinder 63 is carried thereby evening the tension in the belts and therefore the wear of the belts.

Residual vibration from the motor 74 and the grinder 63 is transmitted up the shaft 94 and is further reduced by the arrangement of anti-vibration mounts 106 and 108 in the box section 110 carrying the hand grip portions 98 for the operator. The box section 110 carrying the hand grip portions 98 is connected to the shaft 94 and therefore the rest of the apparatus 60 via the anti-vibration mounts 106 and 113 which absorb vibration from the motor 74 and the grinder 63. Thus the hand grip portions 98 are resiliently mounted to the body section 62 of the apparatus 60 and the orthogonal arrangement of the anti-vibration mounts 106 and 1 13 absorbs much of the vibration travailing up the shaft 94 but at the same time mounting of the handle section 92 is rigid enough for the operator to control the apparatus 60.

In a preferred embodiment, the anti-vibration mounts are formed of rubber.

Also, the compact saw 1 may be used for all floor and road repair work on, for example, concrete or asphalt. Due to the cutting speeds of the saw, conventional saws have a high hand/arm vibration level and embodiments of the present invention may be arranged to reduce this level of vibration.

In a further preferred embodiment, the handgrips are formed of moulded foam to absorb further residual vibration and reduce the transmission thereof to the operator. The struts 40 may be welded to the shaft of the handle section to increase the rigidity thereof and reduce further the vibration transmitted along the shaft.

Various modifications to the embodiments of the present invention described above may be made. For example, whilst the invention has been described with reference to floor grinders and floor saws, the invention is not limited to the use in such apparatus. Thus, although the invention has been described above using particular embodiments, many variations are possible within the scope of the claims as will be clear to the skilled reader.

Claims

Claims 1. A mounting apparatus for mounting a power unit on a main body

section to drive a work tool using a drive belt arrangement, the mounting apparatus comprising: a first section on which a power unit is mountable; a second section attachable to a main body section; a number of antivibration mounts locatable between the first and second sections to absorb vibration caused by the power unit; and a further anti-vibration mount mounted under compression between the first section and the second section and arranged such that its restorative force substantially offsets tension in a drive belt arrangement acting to tilt the power unit in use.
2. A mounting apparatus according to claim 1, wherein the number of antivibration mounts is greater than one.
3. A mounting apparatus according to any one of claims 1 or 2, wherein in use the power unit has a drive shaft, the main body section being attachable in use to a work tool mountable on a further shaft, and wherein the further anti-vibration mount has a longitudinal axis substantially perpendicular to the longitudinal axes of the drive shaft and the further shaft and is arranged such that in use it acts to maintain the longitudinal axis of the drive shaft substantially parallel to the longitudinal axis of the further shaft.
4. A mounting apparatus according to any one of the preceding claims, wherein the number of vibration mounts are formed of rubber material.
b. A mounting apparatus according to any one of the preceding claims, wherein the further vibration mount is formed of rubber material.
6. An apparatus comprising: a power unit; a main body section; a work tool; and a mounting apparatus according to any one of the preceding claims for mounting the power unit on the main body section.
7. An apparatus according to claim 6, wherein the apparatus comprises one or more of a floor grinder and/or a floor saw.
8. A method for mounting a power unit on a main body section to drive a work tool using a drive belt arrangement, the method comprising the steps: mounting a power unit on a first section; locating a number of anti-vibration mounts between the first section and a second section to absorb vibration caused by the power unit; and mounting a further antivibration mount under compression between the first section and the second section such that its restorative force substantially offsets tension in a drive belt arrangement acting to tilt the power unit in use.
9. A handle arrangement for attachment to an apparatus in which vibration is generated comprising: a first section having one or more handgrips; a second section connectable in use to the apparatus; a first pair of antivibration mounts connectable between the first and second sections; a second pair of anti-vibration mounts connectable between the first and second sections; wherein the first pair of anti-vibration mounts is arranged at an angle to the second pair of anti-vibration mounts to inhibit vibrational movement from being transmitted from the first section to the second section in more than one plane.
10. A handle arrangement according to claim 9, wherein each one of the first pair of anti-vibration mounts has an associated longitudinal axis, and wherein the anti-vibration mounts in the first pair are arranged to be coaxial.
11. A handle arrangement according to claim 10, wherein each one of the second pair of anti-vibration mounts has an associated longitudinal axis, and wherein the anti-vibration mounts in the second pair are arranged such that the longitudinal axis of one of the anti-vibration mounts in the second pair is substantially parallel to the longitudinal axis of the other of the anti-vibration mounts in the second pair.
12. A handle arrangement according to claim 11, wherein the first and second pairs of anti-vibration mounts are arranged such that the longitudinal axes of the anti-vibration mounts in the first pair extend in a plane substantially orthogonal to the plane in which the longitudinal axes of the anti- vibration mounts in the second pair extend.
13. A handle arrangement according to any one of claims 9 to 12, wherein the first section comprises a housing for housing the first and second pairs of anti-vibration mounts.
14. A handle arrangement according to any one of claims 9 to 13, wherein the second section comprises an elongate shaft.
15. A handle arrangement according to any one of claims 9 to 14, wherein the one or more handgrips are formed of a rubber material.
16. A handle arrangement according to any one of claims 9 to 15, further comprising one or more struts attachable to said second section for attaching the second section in use to the apparatus.
17. A handle arrangement according to claim 16, wherein the one or more struts are welded to the second section.
18. An apparatus in which vibration is generated comprising the handle arrangement of any one of claims 9 to 17.
19. An apparatus according to claim 18, wherein the apparatus comprises a floor saw.
20. An apparatus according to claim 18, wherein the apparatus comprises a floor grinder.