AU2004200455A1

AU2004200455A1 - Manual percussion or vibration tool with tool handle

Info

Publication number: AU2004200455A1
Application number: AU2004200455A
Authority: AU
Inventors: Jean-Luc Simonin; Alain Vettoretti
Original assignee: Societe de Prospection et dInventions Techniques SPIT SAS
Current assignee: Societe de Prospection et dInventions Techniques SPIT SAS
Priority date: 2003-02-20
Filing date: 2004-02-10
Publication date: 2004-09-09
Anticipated expiration: 2024-02-10
Also published as: AU2004200455B2; FR2851492B1; CA2458051A1; FR2851492A1; EP1449625A2; CA2458051C; EP1449625A3

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S):: Societe de Prospection et d'Inventions Techniques SPIT ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Nicholson Street, Melbourne, 3000, Australia INVENTION TITLE: Manual percussion or vibration tool with tool handle The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5102 la The invention relates to manual pneumatic or electric percuss-ion tools, of the hammer, drill or nail gun type and the like.

To comply with health and safety standards provided within the context of work in legislation, and especially European standards limiting vibrations of hammer handles or other manual percussion apparatus, manufacturers have proposed limiting the vibrations by equipping the handles of the tools with damping devices or coatings made of a flexible material, as described, for example in EP 0 856 385 or in WO 00/64642 in order to damp the impacts and vibrations in the direction of the working axis of the tool.

The solution using coatings seems effective, since the entire handle is covered by the damping coating and the hand is completely protected.

However, apart from the vibrations themselves, these coatings, which are generally plastic, are subject to various corrosive elements, such as water, air, light, UiV, temperature and industrial pollutants which affect their physical properties.

it is for this reason that, periodically, when they have lost their elasticity, they must be replaced.

However, nothing indicates when they are no longer effective enough to comply with the standards above.

The applicant has tried to solve this problem and proposes a manual percussion or vibration tool comprising a tool handle with a coating of a damping material, characterized in that the handle comprises a visual wear indicator.

Thus, it is possible to know when to replace the coating of the handle.

2- Preferably, it is the material of the coating of the handle which f orms the wear indicator, which material visually reveals that it is worn by its change of state caused by the action of the corrosive means.

Preferably again, the coating conforms to the handle in a shape which evens out the stresses f rom mechanical impacts and vibration in the said material, resulting in uniform wear and thus longer life of the material.

Advantageously, the shape of the coating is symmetrical with respect to a plane of symmetry of the tool and is limited by a contact surface and an outer surface whose cross sections in this plane of symmetry are substantially delimited by curves with axes of symmetry parallel to the working axis and with convexities oriented towards the tool. This shape evens out the stresses and conforms with the shape of a hand.

Advantageously, the coating comprises two layers of material having different damping factors fitting together along a joining surface similar to the contact surface separating the handle from the coating so that the spectrum of impacts and vibrations to be damped is more effectively covered, one layer being harder and effective against Vibrations, the other softer and effective against impacts.

Preferably, at least one material is transparent or tranJlucent while it is not worn and makes it possible to visually distinguish an indicator on the handle proving compliance with the standards with regard to damping.

In addition, and by way of intermediate product, the applicant also proposes a detachable handle for a manual percussion or vibration tool provided with a tool handle, which detachable handle is characterized in that it comprises a visual wear indicator, -3 preferably, a flexible coating on a rigid reinforcement, the flexible coating acting as a wear indicator.

Thus it is easy, when the indicator shows marked wear, to replace the detachable handle.

Advantageously, it is by opacitication of the flexible coating that the wear becomes apparent. When it is opacified, the flexible coating conceals a wear marker inscribed on the handle.

Advantageously again, the reinforcement does not cover a central part of the flexible coating. This makes it easier to visually monitor the wear.

Still advantageously, the flexible coati ng comprises a protuberance designed to fit into an opening in the tool. handle and the reinforcement comprises means for fastening the detachable banidle to the tool handl~e- The invention will be better understood by means of the following description and the preferred embodiment of the tool and of the handle of the invention, with reference to the appended drawing, in which Figure 1 shows a perspective view of the tool; Figure: 2 shows schematic sections through the coating of the handle according to the invention and Figure 3 shows a perspective view of the detachable handle according to the invention.

With reference to Figure 1, the manual percussion tool 1 comprises a handle 1L0 for working with 315 percussion along the axis 3 of the tool.

The tool handle 10 is covered with a coating 11 or flexible layer made of a material that damps the impacts caused by the percussions from the tool.

-4 Although not absolutely necessary, in this case the coating comprises a second layer 12, additional to the layer 11, to damp the vibrations of the hand on the handle.

These layers are adhesively bonded or overmoulded one over the other and the first fastened or mounted on the tool handle, thereby forming the coating and both are of appropriate materials so as to damp the entire frequency spectrum of impacts and vibrations generated by the percussions of the tool. In particular, the material of the first flexible layer filters out the high frequencies generated by the impacts and the material of the second layer, which is more rigid, filters out the lower frequencies not filtered by the first layer.

The tool and the tool handle mainly admit a plane of symmetry 4 which separates the body of the tool into two half-shells 10'' and (see Fig. Here, with reference to Figure 2, the layers 11, 12 and the tool handle 10 are applied along the bearing surfaces which are a contact surface 70 between the flexible layer 11 and the tool handle 10, a joining surface 60 between the two layers of the coating 11, 12, and an outer manual gripping surface. These bearing surfaces are at least second order surfaces belonging, in their parts most exposed to the impacts, that is to say in the vicinity of their intersection with the axis 3, substantially to hyperbolic' parabol~oids such that the plane of symmetry 4 intersects them substantially along parabolas 111, 112 in the case of the layer 11 and 121, 122 in the case of the layer 12, and any plane 5 to 7 perpendicular to the plane 4 and parallel to the axis 3 3S intersects them along parabolas 113, 114 to 115, 116, in the case of the layer 11, and 123, 124 to 125, 126, in the case of the layer 12. These surfaces however differ from the hyperbolic paraboloids in that the parabolas 213, 114, 123, 124 and the parabolas 115, 116, 125, 126 do not have, in pairs, for example 113 and 115, equal parameters.

Remember that the parameter P of a parabola is equal to twice the distance separating its focus from the point which is closest to it.

Here, these parameters P depend on the thickness el, e 3 or e 2 e 4 of each of the layers in the plane 5, 7 and on the thickness E of the tool handle so as to even out the stresses in the materials forming them as much as possible, from the axis 3 intersecting the planes and 4 to the axis 6 intersecting the planes 7 and 4 while completely covering the tool handle.

more specifically, if the axis 6 is at a distance d f rom the axis 3 such that the layer has a negligible thickness, the thickness on the axis 3 being a maximum and equal to e 0 then on an intermediate pa-rallel axis 8 separated by x from the axis 3, a thickness e. will be chosen such that substantially: (RI) e e d-x and the parameters P of the. parabolas are chosen according to these thicknesses.

For example, in Figure 2, if a contact surf ace on the tool handle is chosen such that the parabola 151 of axis 8 equivalent to the parabola 113 of axis 3 has a parameter Px and the layer 11 a thickness ex, the tool handle having a constant thickness E, the parabola 152 of the same axis and equivalent to the parabola 114, will have a parameter Py such that substantially: (22) Py P 18Px- -6 Thus, once the value of the parameter P of the parabola 113 of the thicknesses el, *2z of the layers 11, 12 and of the thickness E of the handle are fixed, the bearing surfaces can be completely defined, using the equations RI and R2.

Of course, R can also be chosen as a function of x.

Similarly, the bearing surfaces are such that the parabolas in the planes 5 and 7 and an intermediate plane passing through the axis 8 come closer to each other the further away they move from the axes 3, 8 and 6 such that the stresses in the said material tend to even out in the planes such as 5, 8 and 7. The equation R2 complies with the zero thickness condition at a distance E/2 from the said axes.

it is thus possible to obtain a three -dimensional evening out of the stresses in the layers, uniform wear of the materials and an optimal life in this respect.

Correlatively, if a layer 11, 12 is transparent, with wear it becomes uniformly opaque, which has the effect of concealing the contact surface of the layer 11 on the handle 10 from the user's sight, and therefore concealing a visual wear indicator printed on the surface of the layer 11 or on the tool handle With reference to Pigure 3, the tool handle (10) of the tool is equipped with a detachable handle forming the coating as described above, that is to say comprising two layers of different materials, one, a flexible layer 11, mostly filtering out impacts, for example overmoulded on the second rigid reinforcement 12, which mostly filters out vibrations, with a suitable joining surface The detachable handle 10' fits onto the tool handle along "a contact surface of the type described above, but it comprises a protuberance 45 from its flexible 7layer 11 fitting into an opening 20 made in the upper part of the two half-shells of the tool and of its tool handle.

The detachable handle also comprises a fastening means, for example a screw 41, which fastens, by means of a hole 40 provided in the lower part of the reinforcement 12, the reinforcement to the lower part of the tool handle which has a complementary fastening means, for example a threaded hole 30. The reinforcement is designed to leave the joining surface visible in a central part 50 of the detachable handle located facing an inscription 25 of a wear marker on the contact surface 70 of the tool handle 10 and of the detachable handle 10' such that, since the layer 11 is transparent, this marker appears visually in this central part.

Since the view of this marker fades as the flexible layer wears, the central part 50 forms the wear indicator.

When the marker is no longer visible, all that has to be done is to unscrew the screw 41 and pull the protuberance 45 out of the opening 20 in order to replace the worn detachable handle A tool having a handle with a coating comprising two layers, one layer of which is flexible and one layer of which is rigid, the flexible layer being in contact with the handle, has been considered. Naturally, the reverse could also be envisaged, that is to say placing the rigid layer in contact with the handle.

-8- Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

The reference numerals in the following claims do not in any way limit the scope of the respective claims.

Claims

9- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. Manual percussion or vibration tool comprising a tool handle (10) with a coating 12) of a damping material, characterized in that the handle comprises a visual wear indicator (11, 25, 2. Tool according to Claim 1, in which it is the material of the coating 12) of the handle which forms the wear indicator. 3. Tool according to Claim 2, in which the material visually reveals that it is worn by its change of state. 4. Tool according to one of Claims 1 to 3, in which the coating (11, 12) conforms to the handle in a shape (111, 112, 113, 114; 121, 122, 123, 124) which evens out the stresses from mechanical impacts and vibration in the said material. Tool according to Claim 4, in which the shape of the coating is symmetrical with respect to a plane of symmetry of the tool and is delimited by a contact surface and an outer surface whose cross sections in this plane of symmetry are sub stantially curves (111, 112; 121, 122) with axes of symmetry parallel to the working axis and with convexities oriented towards the tool. 6. Tool according to Claim 5, in which the curves are such that the distance ex between the curves in the plane of symmetry at a given distance x from the axis of symmetry and this distance x, are related by a quadratic equation 7. Tool according to either of Claims 5 and 6, in which the planes 7) perpendicular to the plane of 10 symmnetry and parallel to the working axis (3) intersect the surfaces defining the coating (11, 12) along second degree curves (113, 114; 123, 124; 115, 116; 125, 126) having axes 8, 6) parallel to the working axis. 8. Tool according to Claim 7, in which the second degree curves are parabolas whose parameters P are functions CR2) of the thickness ex of the coating along the axis 8, 6). 9. Tool according to one of the preceding claims', in which the coating comprises two layers (11, 12) of material having different damping factors fitting together along a joining surface (60) similar to the contact surface (70) separating the handle from the coating. Tool according to one of the preceding claims, .in which at least one material (11) is transparent or tranlucent while it is not worn.
11. Tool according to Claim 104 in which the transparent material (1i) makes it possible to visually distinguish an indicator (25) on the handle
12. Detachable handle for a manual percussion or vibration tool provided with a tool handle which detachable handle is characterized in that it comprises a visual wear indicator.
13. Handle according to Claim 12, in which a flexible coating (11) is provided on a rigid reinforcement (12), the flexible coating acting as a wear indicator.
14. Handle according to either of Claims 12 and 13, in which the wear becomes apparent by opacification of the flexible coating (11). 11 Handle according to Claim 14, in which a wear marker (25) is inscribed on the handle
16. Handle according to one of Claims 12 to 15, in which the reinforcement (12) does not cover a central part (50) of the flexible coating (11).
17. Handle according to one of Claims 12 to 16, in which the flexible coating (11) comprises a protuberance (45) designed to fit into an opening in the tool handle
18. Handle according to Claim 17, in which the reinforcement (12) comprises means (40, 41) for fastening the detachable handle to the tool handle -12-
19. A tool substantially as hereinbefore described with reference to the drawings and/or Examples. A detachable handle substantially as hereinbefore described with reference to the drawings and/or Examples.
21. The steps, features, compositions and compounds disclosed herein or referred to or indicated in the specification and/or claims of this application, individually or collectively, and any and all combinations of any two or more of said steps or features. DATED this TENTH day of FEBRUARY 2004 Societe de Prospection et d'Inventions Techniques SPIT by DAVIES COLLISON CAVE Patent Attorneys for the applicant(s) 5108