# Patent

## Title
Wood chisel and blade for a wood chisel

## Abstract

A tool, in particular a wood chisel, includes a first profiled part (100; 1), a second profiled part (103; 10, 14) and a removable blade (106; 20). The second profiled part (103; 10, 14) is pushed into the first profiled part such that the removable blade can be inserted between the first and second profiled parts (100; 1; 103; 10, 14) and be held therein by friction.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tool with a removable blade, in particular a wood chisel and a blade for such a tool.
2. Description of the Related Art
Wood chisels in which the blade is immovable are known. There are also wood chisels comprising a removable blade which can thus be changed in the case of pronounced wear or for varying the types of blade. However, these tools with a removable blade often require the use of a tool for detaching and mounting the blade.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide a tool, in particular a wood chisel, in which the blade is removable and which permits simple and quick changing of the blade without the need for an auxiliary tool for mounting or detaching the blade, whilst guaranteeing that the blade is securely held once it is fixed to said tool. The aim of the present invention is also to provide a removable blade intended to be fitted to a tool, in particular a wood chisel.
The present invention relates to a tool, in particular a wood chisel, comprising a first profiled part, a second profiled part and a removable blade, characterised in that the second profiled part is pushed into the first profiled part such that the removable blade can be inserted between said first and second profiled parts and be held therein by friction.
The present invention also relates to a removable blade intended to be fitted to a tool, in particular a wood chisel, in accordance with the invention.



BRIEF DESCRIPTION OF THE DRAWING FIGURES
The accompanying drawings schematically illustrate by way of example several embodiments of a tool, in particular a wood chisel, with a removable blade, as well as said removable blade in accordance with the invention.
FIGS. 1a and 1b illustrate a wood chisel in accordance with a first embodiment of the invention:

    
    
        FIG. 1a is a view of the partially assembled elements forming said wood chisel,
        FIG. 1b is a view of the fully assembled elements forming said wood chisel.
    
    


FIGS. 2a, 2b and 2c illustrate the first profiled part of a wood chisel in accordance with a second embodiment of the invention:

    
    
        FIG. 2a is a top view of said first profiled part,
        FIG. 2b is a side view of said first profiled part,
        FIG. 2c is a cross-sectional view taken along the axis II-II of the first profiled part illustrated in FIG. 2a. 
    
    


FIGS. 3a and 3b illustrate the core of a wood chisel in accordance with the second embodiment of the invention:

    
    
        FIG. 3a is a top view of said core,
        FIG. 3b is a side view of said core.
    
    


FIGS. 4a, 4b and 4c illustrate the locking element of a wood chisel in accordance with the second embodiment of the invention:

    
    
        FIG. 4a is a top view of said locking element,
        FIG. 4b is a side view of said locking element,
        FIG. 4c is a cross-sectional view taken along the axis IV-IV of the locking element illustrated in FIG. 4a. 
    
    


FIGS. 5a and 5b illustrate the sliding element of a wood chisel in accordance with the second embodiment of the invention:

    
    
        FIG. 5a is a top view of said sliding element,
        FIG. 5b is a side view of said sliding element.
    
    


FIG. 6a illustrates the removable blade of a wood chisel in accordance with the second embodiment of the invention.
FIG. 6b is a profile view of the blade illustrated in FIG. 6a. 
FIG. 7 illustrates a wood chisel in accordance with the second embodiment of the invention wherein the sliding element is in a first closed position.
FIG. 8 illustrates a wood chisel in accordance with the second embodiment of the invention wherein the sliding element is in a second open position.



DETAILED DESCRIPTION OF THE INVENTION
In the first embodiment illustrated in FIGS. 1a and 1b, the tool with a removable blade in accordance with the invention is a wood chisel. Said wood chisel comprises a first profiled part 100 having the form of a substantially rectangular plate whose edges 101 are curved as illustrated in the enlargement 102 of FIG. 1a. 
In accordance with this first embodiment, the wood chisel in accordance with the invention further comprises a second profiled part 103 having the form of a substantially rectangular plate whose edges 104 are curved as illustrated in the enlargement 102 of FIG. 1a. The second profiled part 103 is shaped so as to be able to be inserted into the first profiled part 100 and its length is substantially equal to that of the first profiled part 100.
Preferably, the wood chisel in accordance with the invention further has a core 105 having the form of a substantially rectangular plate and intended to be inserted between the first and second profiled parts 100, 103. The core 105 is used to reinforce the wood chisel in accordance with the invention, thereby improving the rigidity of the tool.
The wood chisel in accordance with the invention further has a removable blade 106 formed from a cutting plate 107 fixedly attached to a fixing plate 108. The cutting plate 107 has at its free end a cutting edge 109. The size and shape of the fixing plate 108 are such that it can be forcibly inserted between the first and second profiled parts, thereby fixing the removable blade to the wood chisel in accordance with the invention. The size of the cutting plate and the angle of the cutting edge may vary depending upon the type of blade.
Preferably, the core is substantially shorter than the first and second profiled parts 100, 103, as illustrated in FIG. 1b, in order to permit the insertion of the fixing plate 108 of the removable blade 106 between the first and second profiled parts 100, 103.
In order to remove the removable blade 106, it only has to be pulled by the cutting plate out of the first and second profiled parts. Preferably, the first and second profiled parts each comprise a first oblong opening 110 at their end receiving the removable blade. The removable blade 106 for its part comprises a hole 111 in the fixing plate 108. The first oblong openings 110 and the hole 111 are such that when the removable blade 106 is inserted between the first and second profiled parts 100, 103 the hole 111 is visible through the oblong openings 110 as illustrated in FIG. 1b. This enables in particular the removable blade 106 to be easily removed from the wood chisel.
In the second embodiment illustrated in FIGS. 2 to 8, the tool with a removable blade in accordance with the invention is likewise a wood chisel. As in the first embodiment, said wood chisel comprises a first profiled part 1 illustrated in FIG. 2a and having the form of a substantially rectangular plate. A first end 1a of the first profiled part 1 is shaped to be able to be inserted and held in a handle (not shown) of the wood chisel.
As illustrated in FIGS. 2a and 2c, the first profiled part 1 has curved edges 2 along its entire length, except for at its first end 1a. 
The first profiled part 1 further comprises different openings whose function will be described hereinafter. A first hole 3 is produced in the first profiled part 1 at its first end 1a. The first profiled part 1 further comprises a second hole 4 located between its curved edges 2. Finally, the first profiled part 1 further has two positioning holes 5 at its second end 1b. 
The wood chisel in accordance with the second embodiment of the invention comprises a core 6 illustrated in FIG. 3a and having the form of a substantially rectangular plate. The core 6 is shaped so as to be able to be slid between the curved edges 2 of the first profiled part 1. The core 6 likewise has an end 6a matched in terms of size and shape to the first end 1a of the first profiled part 1 and intended to be inserted and held in the handle of the wood chisel. The core 6 is used to reinforce the wood chisel in accordance with the invention.
At its end 6a on a first face, the core 6 comprises a first protuberance 7 intended to co-operate with the first hole 3 of the first profiled part 1 to guarantee that the core 6 is suitably positioned and held with respect to the first profiled part 1. The core 6 further comprises, still at its end 6a, a second protuberance 8. As illustrated in FIG. 3b, this second protuberance 8 is located on the second face (opposite the first face) of the core 6 and is thus directed in a direction opposite that of the first protuberance 7. Moreover, still with reference to FIG. 3b, the core 6 has first and second recesses 7a, 8a corresponding to the first and second protuberances 7, 8 respectively. The first recess 7a and the second protuberance 8 are located on the same second face of the core 6. Similarly, the second recess 8a and the first protuberance 7 are located on the same face of the core, opposite the second face.
The core 6 further has an oblong opening 9 extending in parallel with the longer sides of said core 6.
In this second embodiment, the second profiled part is composed of two elements: a locking element 10 and a sliding element 14.
The locking element 10 illustrated in FIG. 4a has a substantially rectangular shape. The locking element 10 comprises a first portion 10a matched in terms of size and shape to the first end 1a of the first profiled part 1 and to the first end 6a of the core 6 and likewise intended to be inserted and held in the handle of the wood chisel. The second portion 10b of the locking element 10 comprises lateral flanges 11 illustrated in FIGS. 4b and 4c. The second portion 10b and the lateral flanges 11 are shaped such that the locking element 10 can be inserted into the first profiled part 1 and that the core 6 is held between said first profiled part 1 and the locking element 10 by the combined insertion effect of the bent edges 2 of the first profiled part 1 and the lateral flanges 11.
Moreover, the locking element 10 comprises on its first portion 10a a third hole 12 intended to co-operate with the second protuberance 8 of the core 6 so as to guarantee that the locking element 10 is suitably positioned with respect to the core 6.
The locking element 10 further comprises a tab 13 cut from its second portion 10b. Said tab 13 is shaped so as to have a certain degree of resiliency under pressure along an axis perpendicular to the longitudinal axis of the locking element 10. Preferably, the tab 13 has a substantially circular portion 13a providing a suitable pressing area for the user, fixedly attached to the locking element 10 by an arm 13b. In a likewise preferable manner, the tab 13 has on its free end a finger 13c whose function will be described hereinafter.
The wood chisel in accordance with the invention further comprises a sliding element 14 illustrated in FIGS. 5a and 5b and having the form of a substantially rectangular plate. The sliding element 14 comprises a first portion 14a preferably having two ridges 15 intended to facilitate handling of the sliding element 14 by the user. The end of this first portion 14a of the sliding element 14 has a cut-out 17 intended to co-operate with the finger 13c of the tab 13 of the locking element 10.
The second portion 14b of the sliding element 14 has lateral flanges 16 extending perpendicularly to the longitudinal axis of the sliding element on the side opposite the ridges 15. Still on the face opposite that having the ridges 15, the sliding element has a stop 18 intended to slide in the oblong opening 9 of the core 6.
The lateral flanges 16 of the sliding element 14 are shaped such that said sliding element 14 can be displaced in the first profiled part 1, said lateral flanges sliding between the bent edges 2 of the first profiled part 1 and the core 6.
The assembly and operation of the wood chisel in accordance with this second embodiment will now be described in detail. The core 6 is inserted into the first profiled part 1, its positioning being ensured by the insertion of the first protuberance 7 of the core 6 into the first hole 3 of the first profiled part 1. The locking element 10 is then inserted in the first profiled part 1. Said locking element is correctly positioned when the second protuberance 8 of the core 6 is correctly pushed into the third hole 12 of the locking element. Owing to the shape of the first profiled part 1, of the core 6 and of the locking element 10, the latter can be removed from the first profiled part 1 only by displacing it along the longitudinal axis of the first profiled part. In particular, said locking element cannot be removed from the first profiled part 1 vertically. Therefore, once in its operational position, the locking element 10 is pushed into the first profiled part 1 and also locks the core 6 in said first profiled part 1.
The size of the core 6 is such that once the first profiled part 1, the core 6 and the locking element 10 are in their operational position, the positioning holes 5 are not covered by the core and are accessible to the user, as illustrated in FIG. 8.
The sliding element 14 is inserted into the first profiled part 1 such that the lateral flanges 16 of said sliding element 14 enclose the core 6. Owing to the shape of the first profiled part 1 and of the sliding element 14, the latter cannot be removed from the first profiled part vertically. As was the case for the locking element 10, the sliding element 14 can only be displaced laterally along the longitudinal axis of the first profiled part 1.
Displacement of the sliding element 14 with respect to the first profiled part 1 is limited by the travel of the stop 18 in the oblong opening 9 of the core 6. Moreover, in the closed position, the finger 13c of the tab 13 of the locking element 10 co-operates with the cut-out 17 of the sliding element 14 to lock it and prevent it from sliding further forward with respect to the first profiled part 1. This closed position is illustrated in FIG. 7. The size of the sliding element 14 is such that in this closed position, the sliding element covers the positioning holes 5 of the first profiled part 1, these thus being inaccessible for the user.
In order to displace the sliding element 14 into its open position, the user must press the tab 13, via its circular portion 13a, so as to disengage the finger 13c from the cut-out 17. Whilst keeping pressure on the tab 13, the user can then slide the sliding element 14 over the locking element 10, thereby uncovering the positioning holes 5 of the first profiled part 1. The travel of the sliding element 14 is limited by the stop 18 sliding in the oblong opening 9. The locking element 10 and the sliding element 14 are shaped such that the latter can slide over the former. This open position is illustrated in FIG. 8.
The wood chisel in accordance with the second embodiment of the invention further comprises a removable blade 20 illustrated in FIG. 6a. The removable blade 20 comprises a fixing plate 21 having retaining means having for example the form of first and second lugs 22 intended to co-operate with the positioning holes 5 of the first profiled part 1. The size and shape of the fixing plate are such that it can be inserted in the first profiled part 1 and between said profiled part 1 and the sliding element 14.
The removable blade 20 further comprises a cutting plate 23 fixedly attached to the fixing plate 21. The free end of the cutting plate 23 has a cutting edge 24. The size of the cutting plate and the angle of the cutting edge may vary depending upon the type of blade.
When the sliding element 14 is in the open position, the removable blade 20 is placed in the first profiled part 1. The suitable positioning of the blade 20 is ensured by the snap-fitting of the first and second lugs 22 in the positioning holes 5 of the first profiled part 1. In order to ensure the fixing of the removable blade 20 to the wood chisel in accordance with the invention, the user must now displace the sliding element 14 into its closed position by sliding it with respect to the first profiled part 1. Once the sliding element is in its closed position, the fixing plate 21 of the removable blade 20 is completely covered by the sliding element 14 which thus keeps the removable blade 20 fixedly attached to the wood chisel in accordance with the invention.
The present embodiment has been described by way of example only. In particular, the tab 13 could be replaced by any suitable resilient force. Similarly, the various positioning means, such as the protuberances, the recesses, the stops, could be replaced by any other suitable positioning means.
The angle a between the cutting plate 23 and the fixing plate 21 of the removable blade may vary depending upon the type of blade. However, the cutting plate 23 is adjusted with respect to the fixing plate 21 so as to form a shoulder 25 shaped such that possible material shavings lifted off during use of the wood chisel in accordance with the invention cannot come to slide between the sliding element 14 and the removable blade 20. This variation for the removable blade can likewise be applied to a removable blade intended to be fitted to a wood chisel in accordance with the first embodiment. The cores 105, 6 described in the two embodiments described above are optional in both cases.

## Claims

1. A tool, comprising:
a first profiled part having at one end positioning means for a removable blade;
a locking element having at least one portion shaped to be inserted into the first profiled part;
a sliding element shaped to be displaced in the first profiled part in a longitudinal direction parallel to a longitudinal axis of the first profiled part and fixed with respect to the first profiled part in a direction perpendicular to said longitudinal axis; and
a removable blade having retaining means intended to co-operate with the positioning means of the first profiled part to position and retain the removable blade on said profiled part in a longitudinal direction parallel to the longitudinal axis of the first profiled part,
wherein the locking element and the sliding element are shaped so that the sliding element can slide over the locking element when the locking element is displaced in the first profiled part in the longitudinal direction parallel to the longitudinal axis of the first profiled part, and
the sliding element is conformed to be displaced with respect to the first profiled part and the locking element between an open position in which the positioning means at the end of the first profiled part are accessible/uncovered and the removable blade can be placed on the first profiled part, retaining means co-operating with the positioning means of the said profiled part to ensure proper positioning of said removable blade and a closed position in which the sliding element covers the positioning means of the first profiled part and the removable blade positioned on the first profiled part so that said removable blade is held fixed between the first profiled part and the sliding element and cannot be removed from there without displacing back the sliding element in the sliding element's open position.

2. The tool as claimed in claim 1 wherein the tool further comprises first locking means on the locking element and second locking means on the sliding element, the first and second locking being conformed to co-operate when the sliding element is in the closed position to block said sliding element in said closed position.

3. The tool as claimed in claim 2, wherein the first locking means comprise a resilient tab conformed to be pressed by the user in a direction perpendicular to the longitudinal axis of the first profiled part and having at its end a finger designed to co-operate with a cut-out of the sliding element and said cut-out constituting the second locking means.

4. The tool as claimed in claim 3, wherein the tool further comprises a core positioned between the first profiled part and the locking element.

5. The tool as claimed in claim 4, wherein the core presents an oblong opening and the sliding element presents a stop designed to slide inside said opening and limit the displacement of the sliding element with respect to the locking element and the first profiled part.

6. The tool as claimed in claim 2, wherein the tool further comprises a core positioned between the first profiled part and the locking element.

7. The tool as claimed in claim 6, wherein the core presents an oblong opening and the sliding element presents a stop designed to slide inside said opening and limit the displacement of the sliding element with respect to the locking element and the first profiled part.

8. The tool as claimed in claim 1, wherein the tool further comprises a core positioned between the first profiled part and the locking element.

9. The tool as claimed in claim 8, wherein the core presents an oblong opening and the sliding element presents a stop designed to slide inside said opening and limit the displacement of the sliding element with respect to the locking element and the first profiled part.