EP3060360A1

EP3060360A1 - Hand tool step drive mechanism, crimping pliers provided with such a mechanism, and crimping method

Info

Publication number: EP3060360A1
Application number: EP14806070.0A
Authority: EP
Inventors: Lionel Marcon
Original assignee: Pierre Grehal et Cie SA
Current assignee: Edma
Priority date: 2013-10-21
Filing date: 2014-10-21
Publication date: 2016-08-31
Anticipated expiration: 2034-10-21
Also published as: US20160279765A1; EP3060360B1; WO2015059635A1; AU2014338604B2; US10195721B2; FR3012056B1; ES2955670T3; FR3012056A1; PL3060360T3

Abstract

The present invention relates to a step drive mechanism to be attached into the hollow body of a tool, making it possible to produce a thrust movement that can be easily carried out. To this end, the mechanism includes: a rack (2) that has a first (3) and a second (4) cog having back-slanted teeth (3a, 4a) arranged on an upper (2a) and a lower (2b) edge, respectively; a front end (2c); a pivotable lever (5) that comprises a hollow top end (5a) receiving a torsion spring (8), bearing against said hollow top end (5a) of the lever and against a thrust pawl (7) pivoting in the hollow body (1) in front of the hollow top end (5a) of the lever, and has a crosspiece (7a) inserted between the teeth (3a) of the first cog (3); and a pivotable locking pawl (8) provided with a crosspiece (8a) inserted between the teeth (4a) of the second cog (4). A compression spring (9) is arranged such as to bear against the locking pawl (8) and against an abutment (2d) located at a rear end (2e) of the rack (2).

Description

PUSH-TO-STEP PUSH MECHANISM FOR HAND TOOL, CRIMP TOOL PROVIDED WITH SUCH MECHANISM AND CRIMPING METHOD

The invention relates to a step-by-step push mechanism for a hand tool, a crimping tool provided with such a mechanism, and a crimping method using such a clamp.

A crimping tool is used to crimp two pieces together. In particular, these parts are advantageously open metal profiles arranged one against the other and used, in particular, in certain structures or frameworks of assembly of plasterboard, wall or ceiling.

Conventionally, the metal profiles used have a sectional shape of U.

They generally have a sheet thickness of between 0.5 and 1 mm, so that during crimping, the user must drill between 1 and 2 mm of sheet metal with the punch.

A user may have to do several tens of crimps in a day's work, so that if the first crimps are easy, the following tend to become more and more tiring.

In addition to the drilling of the sheets, the stripping (that is to say the withdrawal of the punch out of the crimp) is also generating forces, being reminded that the stripping force increases when the punch heats, that is to say say after many uses.

For professionals, these efforts often generate musculoskeletal disorders that contribute to the hard work.

The object of the present invention is therefore to provide a step-by-step pushing mechanism making it possible to obtain a pushing movement that is easier to implement, in particular for driving a punch into crimping sheets. To this end, the object of the invention is a step-by-step push mechanism for hand tools, such as a crimping pliers, intended to be fixed in a hollow body having a rear end and a front end. The mechanism is characterized in that it comprises, with reference to the normal position of use and the direction of thrust:

A rack adapted to be slidably mounted in the hollow body between an initial position and a final position, and having:

o two longitudinal edges, respectively upper and lower; a first toothing with rearwardly inclined teeth arranged on one of the two longitudinal edges;

oa second gear teeth inclined rearwardly arranged on ^the other of the two longitudinal edges;

o a front end;

A lever intended to be pivotally mounted in the hollow body between a maximum clamping position and an initialization position, said lever comprising a hollow upper end receiving a torsion spring bearing against said hollow upper end of the lever and bearing against a pawl-called "push" to be pivotally mounted in the hollow body, in front of the hollow upper end of the lever and provided ^with a cross member engaged between the teeth of the first toothing;

A pawl called "locking" intended to be pivotally mounted in the hollow body and provided with a cross member engaged between the teeth of the second toothing, a compression spring being arranged in abutment against the locking pawl and resting against a stop located at a rear end of the rack.

According to a particular embodiment, the locking pawl has, in addition:

• a contact surface with the push pawl; and

• a contact surface with the hollow upper end of the pivoting lever:

said contact surfaces being arranged to cause clearance of the cross member of the locking pawl at the same time as the cross member of the pawl when the pivoting lever is rotated to the initialization position.

The invention also relates to a crimping pliers for crimping two parts together, such as sheets, comprising with reference to the normal position of use and the direction of thrust:

A hollow body having a rear end and a front end;

• a fixed handle integral with the hollow body;

A rack slidably mounted in the hollow body between an initial position and a crimping position, and having:

a first toothing with rearwardly inclined teeth arranged on an upper edge;

a second toothing with rearwardly inclined teeth arranged on a lower edge;

o a front end with a punch;

A lever-shaped handle pivotally mounted in the hollow body between a maximum clamping position and a stripping position, said handle having a hollow upper end receiving a torsion spring bearing against said hollow upper end and resting against a ratchet said "thrust" pivotally mounted in the hollow body, in front of the upper hollow end, and provided with a cross member engaged between the teeth of the first toothing;

A pawl called "locking" pivotally mounted in the hollow body and provided with a cross member engaged between the teeth of the second toothing, a compression spring being arranged in abutment against the locking pawl and in abutment against a stop located at a rear end of the rack.

According to other embodiments:

The front end and the rear end of the rack may each be provided with at least one guide pin each engaged in an oblong slot formed at the front and at the rear of the hollow body, so that the rack is slidably mounted in the hollow body by double guiding; The front end of the hollow body may have a crimping hook provided with a crimping end intended to be positioned in abutment behind the parts to be crimped, the crimping end being situated at a determined distance from the punch carried by the front end of the rack in the initial position, so ^that in use, the punch comes into contact with a first of the two parts to be crimped, to a contact position when (a handle pivotally mounted is in an intermediate clamping position range between a zero clamping position and the maximum clamping position, the zero clamping position being between the maximum clamping position and the stripping position;

The intermediate clamping position can be, relative to the zero clamping position, between 20% and 80% of the maximum clamping position, preferably between 60% and 40% of the maximum clamping position, advantageously at 50%; % of the maximum tightening position.

A length of the oblong slots may be chosen so that the guide pins abut with a front end of the oblong slots at the end of crimping;

The locking pawl can furthermore present:

- a contact surface with the push pawl; and

a contact surface with the hollow upper end of the pivoting handle,

said contact surfaces being arranged to cause clearance of the cross member of the locking pawl together with the cross-member of the pawl when the pivoting handle is pivoted to the stripping position.

The invention also relates to a crimping method for crimping two pieces together, such as sheets, comprising:

a) The supply of both pieces;

b) positioning the two parts in a crimping position;

(c) Provision of a previous crimping tool; d) the positioning of the front end of the hollow body behind the parts with reference to the direction of thrust of the rack, said rack being in an initial position;

e) The stepwise pushing of the rack towards the two parts by successive tightenings of the pivoting handle towards the fixed handle, with a clamping force less than a clamping force necessary for the punching of the pieces, until the punch is in a position of contact with a first of the two pieces;

f) The application of a sufficient clamping force to pierce both pieces with the punch;

g) The stepwise pushing of the rack through the two parts by successive tightening of the pivoting handle towards the fixed handle, with a clamping force less than a clamping force necessary for drilling the pieces by the punch, until crimping of both pieces is obtained.

According to a particular embodiment, during step e), the pivoting handle is in an intermediate position between the zero clamping position and the maximum clamping position when the punch is in the position of contact with a first of the two parts.

Other features of the invention will be set forth in the detailed description below, made with reference to the accompanying drawings, which represent, respectively:

- Figure 1, a schematic plan view of a step-by-step pushing mechanism according to the invention;

- Figure 2. a schematic plan view of a crimping pliers provided with a step-by-step thrust mechanism according to the invention, in the initial position and in zero clamping position;

- Figure 3, a schematic plan view of a crimping tool provided with ^a pushing mechanism for step-by-step according to the invention, during pressing and maximum tightening position; and - Figure 4 is a schematic plan view of a crimping pliers provided with a step-by-step pushing mechanism according to the invention, in the stripping position.

The step-by-step push mechanism illustrated in FIG. 1 can be used in any type of hand tool requiring a thrust force and not a pulling force. For example, it may be a crimping pliers, as described later, but also a cutting tool in which the blade is pushed against a stop.

The following description of the mechanism and the crimping tool according to the invention is made with reference to the normal use position (that which is illustrated) and to the thrust direction F1. For example, a "before" structure. respectively a "rear" structure means that this structure is located towards the front, respectively towards the rear, of the tool when the user holds it in the position of use. The tool according to the invention being designed to generate a thrust, ceia means that a rear structure of the tool is located close to the user, while a front structure is located at a distance from the user.

The mechanism according to the invention is intended to be mounted in a hollow body 101 (see Figure 2) of a tool and having a rear end 101a and a front end 101b. Advantageously, this hollow body is constituted by a folded sheet on itself to form a U. Alternatively, it may be a molded part.

The mechanism comprises a rack 2 intended to be slidably mounted in the hollow body, between an initial position Pi and a final position PF-

In a general way, the rack presents:

o two longitudinal edges 2a, 2b, respectively upper and lower;

a first toothing 3 with rearwardly inclined teeth 3a arranged on one of the two longitudinal edges;

a second toothing 4 with teeth inclined rearwardly 4a arranged on the other of the two longitudinal edges; o a front end 2c.

In the preferred embodiments illustrated and described below, the rack has:

a first toothing 3 with rearwardly inclined teeth 3a arranged on the upper edge 2a;

a second set of teeth 4 with rearward inclined teeth 4a arranged on the lower edge 2b.

A lever 5 is intended to be pivotally mounted in the hollow body 101. between a maximum clamping position PSM and an initialization position P ₀ ev.

The maximum clamping position PSM means that the lever is pivoted to the maximum to advance the rack one step, and the initialization position P ₀ ev _> means that the lever is rotated to this position to reposition the rack in its initial position. ft.

The lever comprises a hollow upper end 5a receiving a torsion spring 6 bearing against said hollow upper end 5a of the lever and resting against a pawl 7 called "thrust" also intended to be pivotally mounted in the hollow body 101. forward of the upper hollow end 5a of the lever so that a cross member 7a fitted to the pawl is engaged between the teeth 3a of the first toothing 3.

Thus, when the lever is pivoted according to the arrow F2, to the maximum clamping position PSM. it pushes the pawl 7 according to the arrow F3 (see Figure 2) through the torsion spring 6. The cross member 7a is engaged with a tooth inclined backwards, it pushes the rack in the direction of the arrow F 1.

The mechanism also comprises a pawl 8 called "locking", intended to be pivotally mounted in the hollow body 101, and provided with a cross member 8a engaged between the teeth 4a of the second toothing 4. a compression spring 9 being arranged in bearing against the locking pawl 8 and bearing against a stop 2d located at a rear end 2e of the rack 2. Thus, when the lever is pivoted according to the arrow F2, and the rack is pushed forward (arrow F1). 8a through 8a slides along a tooth 4a of the second toothing. As soon as the cross member 8a exceeds the end of the tooth, the compression spring 9 forces the cross member 8a to lock behind the tooth, so that the rack is locked in this position.

The torsion spring has a function of returning the pivoting lever from the maximum clamping position P _M to a clamping position nui Pso. or position of rest, located between the maximum clamping position P _M and the initialization position P _D ev. During this return of the lever in the zero clamping position, the rack is locked.

Cran after notch, the rack is advanced by successive tightening of the pivot.

In end position PF (for example when crimping is obtained), it is necessary to release the rack.

For this, the user pivots the lever in the direction of the arrow F6 (see Figure 4) to the initialization position.

The locking pawl 8 has, in addition: a contact surface 8b with the pawl 7; and

A contact surface 8c with the hollow upper end 5a of the pivoting lever 5.

These contact surfaces 8b. 8c are arranged to cause the clearance of the cross member 8a of the locking pawl 8 at the same time as the crossbar 7a of the pawl 7 when the pivoting lever 5 is pivoted to the initialization position P _D EV (arrow F6). Indeed, when the lever is pivoted in the direction of the arrow F6, ^the hollow upper end 5a of the pivot lever 5 comes into contact with the surface 8c and pivots the locking pawl 8 in the direction of the arrow F4. The surface 8b of the contact locking pawl then comes into contact with the thrust pawl 7 and rotates in the direction of the arrow F5. The crosspieces of the pawls are then forced out of the teeth, thus releasing the rack. The compression spring 9 then relaxes and reposition the rack in the initial position.

Thus, in addition to its constraint function of the cross member 8a, the compression spring also has a double return function:

A first function of returning the rack from the final position PF (for example when crimping is obtained) to its initial position and

A second lever return function from the POEV initialization position (for example the control position of the stripping for a crimping tool) to the zero clamping position P. $ o. or rest position.

Figures 2 to 4 illustrate a crimping pliers 100 provided with a mechanism according to the invention.

This clip includes:

A hollow body 101 having a rear end 101a and a front end 101b;

A fixed handle 102 integral with the hollow body 101;

• A rack 103 slidably mounted in the hollow body 101 between an initial position Pi and a crimping position PF (see Figure 4).

The rack shows:

a first toothing 104 with rearwardly inclined teeth 104a arranged on an upper edge 103a;

a second set of teeth 105 with rearwardly inclined teeth 105a arranged on a lower edge 103b;

c a front end 103c provided with a punch 106.

A lever handle 107 is pivotally mounted in the hollow body 101 between a maximum clamping position PSM (shown in dashed lines in FIG. 2) and a stripping position Poev (illustrated in FIG. 4).

The pivoting handle 107 is mounted forward of the fixed handle 102, i.e. the handle 107 is located between the fixed handle and the front end 101b of the hollow body. In other words. in use, a pivoting of the pivoting handle 107 towards the maximum clamping position PSM generates an advance of the punch towards the front end 101b of the hollow body 101.

This arrangement allows the user to apply an optimum force since his movable fingers are in contact with the pivoting handle 107, while his palm, immobile, receives the fixed handle 102.

The movable handle 107 has a hollow upper end 107a receiving a torsion spring 108 bearing against said hollow upper end 107a and resting against a pawl 109 called "thrust" pivotally mounted in the hollow body 101, in front of the end upper hollow 107a. and provided with a cross member 109a engaged between the teeth 104a of the first toothing 104.

A pawl 110 called "locking" is also pivotally mounted in the hollow body 101 and is provided with a cross 110a engaged between the teeth 105a of the second toothing 105. A compression spring 111 is arranged in abutment against the pawl of locking 110 and bearing against a stop 103d located at a rear end 103e of the rack 103.

^The front end 103c and the rear end 103 of the rack 103 are each provided with at least one guide pin 112-

113 each engaged in a 114-115 oblong slot formed in ^the front and rear of the hollow body 101, so that the rack 103 is slidably mounted in the hollow body by a double guide.

Advantageously, the lugs are each engaged with two parallel oblong slots located on either side of the rack in the hollow body. This improves the quality of the thrust and therefore the crimping because the punch is guided on each side, forward and backward.

Like the conventional crimping pliers, the front end 101b of the hollow body 101 has a crimping hook 120 provided with a crimping end 121 intended to be positioned in abutment behind the crimping plates. According to an advantageous embodiment of the invention, the crimping end 121 is situated at a determined distance D from the front end of the punch 106 carried by the front end 103a of the rack 103 in the initial position P "of such so that in use, the punch comes into contact with a first of the two sheets, at a contact position Pc, when the pivotally mounted handle is in an intermediate clamping position Psn, Psi2. Psi3 between the zero clamping position Pso and the maximum clamping position Ρ $ Μ ·

This feature of the invention allows crimping much easier than if the punch came into contact with the sheet at the end of the race or at the beginning of the race of the pivoting handle.

Indeed, the most critical phase of crimping is the drilling of the sheets. Before this breakthrough, the ^user does apply little effort to get the punch in contact with the sheet. After drilling, the crimping resistance is generated solely by the friction of the punch against your sheets. The effort required during this phase is greater than to bring the punch into contact with the sheets, but less important than the effort required for drilling.

Although the use of a step-by-step mechanism according to the invention greatly facilitates the crimping, the Applicant has found ^that by selecting a distance D such that the contact between the punch and the sheet metal occurs when the pivoting handle is in an intermediate position between the zero clamping position Pso and the maximum clamping position PSM, the drilling of the sheets was facilitated.

Thus, the invention takes advantage of the fact that the clamping power of the user is maximum when his hand n ^! is not in the position ^of maximum extension (the position of the pivoting handle being then the zero clamping position Pso). in the maximum tightening position (the position of the pivoting handle is then the maximum tightening position PSM).

Preferably, the intermediate clamping position Psn, Psi2,

Pso is included, relative to the zero clamping position Pso. between 20% and 80% of the maximum clamping position, preferably between 60% and 40% of the maximum clamping position, advantageously at 50% of the maximum clamping position.

An intermediate clamping position at X% of the maximum clamping position means that the pivoting handle is at an angular distance from the maximum clamping position equal to X% of the angular distance between the maximum clamping position and the clamping position. zero tightening.

The fatigue due to repeated crimps is therefore reduced. The corollary is that users with less physical strength than professionals can easily perform rail crimps.

According to another aspect of the invention, the length L1 of the oblong slots 114-115 is chosen so that the guide pins 112-113 abut with the front end 114a-115a of the oblong slots 1 14-115 at the end of crimping.

This ensures that the punch can not continue its course, at the risk of destroying the crimp. This also allows the user to make successive tightenings of the pivoting handle until the guide pins 112-113 abut with the front end 114a-1 15a oblong slots without fear of damaging the crimping.

When crimping is complete, the user only has to pivot the pivoting handle towards the stripping position (see Figure 3).

For this purpose, the locking pawl 110 further has: a contact surface 110b with the pawl 109; and

A contact surface 110c with the hollow upper end 107a of the pivoting handle 107.

The contact surfaces 110b, 110c are arranged to cause the clearance of the cross member 1 10a of the locking pawl 1 10 together with the cross 109a of the pawl 109 when the pivoting handle is pivoted to the stripping position. In this position, the compression spring 9 relaxes and automatically reposition the rack in the initial position Pi.

The user does not have to provide effort during stripping, unlike conventional clamps that force "user to move the handles to get out the punch crimping.

The compression spring 9 is thus chosen to have sufficient stiffness to remove the crimping punch (stripping).

The torsion spring 6, 108 is chosen to have a sufficient stiffness to allow, after a tightening, the return of the pivoting handle to the zero clamping position Pso- Alternatively, if the hollow body does not have an internal volume sufficient to allow the use of a torsion spring 6. 108 sufficiently stiff, a third spring can be added between the pivoting handle and the fixed handle to bias the movable handle to the zero clamping position Pso- With the crimping pliers according to the invention, the crimping method comprises:

(a) The supply of two sheets to be crimped to one another;

b) The positioning of the two sheets in a crimping position;

c) The provision of a crimping tool according to the invention,

d) the positioning of the front end of the hollow body behind the sheets in reference to the thrust direction of the rack, said rack being in an initial position Pi;

e) The stepwise pushing of the rack towards the two sheets by successive tightenings of the pivoting handle towards the fixed handle, with a clamping force less than a clamping force necessary for drilling the sheets by the punch, until the punch is in a contact position Pc with a first of the two sheets;

f) The application of a sufficient clamping force to pierce the two sheets with the punch;

g) The stepwise pushing of the rack through the two plates by successive tightening of the pivoting handle towards the fixed handle, with a clamping force lower than a clamping force necessary for drilling sheets by the punch, until the crimping of the two sheets is obtained.

Then, the method comprises a stripping step of pivoting the pivoting handle towards the stripping position so as to release the sleepers of the pawls out of the toothings of the rack, thereby releasing the compression spring which automatically repositions the rack in the initial position Pi .

Preferably, during step e). the pivoting handle is in an intermediate position Psn, Psis. Pso between the zero clamping position Pso and the maximum clamping position PSM when the punch is in the contact position Pc with a first of the two sheets.

Claims

1 Step-by-step push mechanism (10) for hand tools, such as a crimping pliers, to be fixed in a hollow body (1) having a rear end (1a) and a front end (1b) , characterized in that it comprises, with reference to the normal position of use and the thrust direction (F1):

A rack (2) intended to be slidably mounted in the hollow body (1) between an initial position (Pj) and a final position (PF), and having:

o two longitudinal edges (2a, 2b), respectively upper (2a) and lower (2b)

a first toothing (3) with teeth inclined towards the rear (3a) arranged on one of the two longitudinal edges (2a, 2b); a second toothing (4) with rearwardly inclined teeth (4a) arranged on the other of the two longitudinal edges (2b, 2a); a front end (2c);

A lever (5) to be pivotally mounted in the hollow body (1) between a maximum clamping position (PSM) and an initialization position (PDEV). said lever having a hollow upper end (5a) receiving a torsion spring (6) bearing against said hollow upper end (5a) of the lever and resting against a pawl (7) called "thrust" to be pivotally mounted in the hollow body (1), in front of the hollow upper end (5a) of the lever, and provided with a cross member (7a) engaged between the teeth (3a) of the first toothing (3);

• a pawl (8) called "lock" intended to be pivotally mounted in the hollow body (1) and provided with a cross member (8a) engaged between the teeth (4a) of the second toothing (4). a compression spring (9) being arranged in abutment against the locking pawl (8) and resting against an abutment (2d) located at a rear end (2e) of the rack (2).

The stepwise pushing mechanism according to claim 1, wherein the locking pawl (8) further has: A contact surface (8b) with the pusher (7); and

A contact surface (8c) with the hollow upper end (5a) of the pivoting lever (5);

said contact surfaces (8b, 8c) being arranged to disengage the cross member (8a) of the locking pawl (8) at the same time as the cross member (7a) of the pawl (7) when the pivoting lever (5) ) is rotated to the initialization position (Poev) -

3. Clamp (100) for crimping to crimp the two parts together, characterized in ^that it comprises, with reference to the normal use position and the direction of thrust:

A hollow body (101) having a rear end (101a) and a front end (101b);

• a fixed handle (102) integral with the hollow body (101);

A rack (103) slidably mounted in the hollow body (101) between an initial position (Pi) and a crimping position (PF). and having: a first toothing (104) with rearwardly inclined teeth (104a) arranged on an upper edge (103a);

c a second toothing (105) with rearwardly inclined teeth (105a) arranged on a lower edge (103b);

a front end (103c) provided with a punch (106);

A lever-shaped handle (107) pivotally mounted in the hollow body (101) between a maximum clamping position (PSM) and a stripping position (Poev). said handle (107) having a hollow upper end (107a) receiving a torsion spring (108) bearing against said hollow upper end (107a) and resting against a pawl (109) said "thrust" pivotally mounted in the body hollow (101), in front of the upper hollow end (107a), and provided with a cross member (109a) engaged between the teeth (104a) of the first toothing (104);

A pawl (110) called "locking" pivotally mounted in the hollow body (101) and provided with a cross member (110a) engaged between the teeth (105a) of the second toothing (105), a compression spring (11) 1) being arranged resting against the locking pawl (1 10) and bearing against a stop (103d) located at a rear end (103e) of the rack (103).

4. Crimping pliers according to claim 3, wherein the front end (103c) and the rear end (103e) of the rack (103) are each provided with at least one guide pin (112-1 13). each engaged in an oblong slot (1 14-1 15) arranged at the front and rear of the hollow body (101), such that the rack (103) is slidably mounted in the hollow body by double guiding .

5. Crimping tool according to any one of claims 3 or 4, wherein ^the front end (101b) of the hollow body

(101) has a crimping hook (120) having a crimping end (121) to be positioned abutting behind the crimping pieces, the crimping end (121) being located at a determined distance (D) the punch (106) carried by ^the front end (103a) of the rack (103) in the initial position (P) such that in use, the punch comes into contact with a first of the two parts to be crimped, at a contact position (Pc), when the pivotally mounted handle is in an intermediate clamping position (Psn, Psiz, Psia) between a zero clamping position (Pso) and the maximum clamping position (PSM), the position zero clamping force (Pso) being located between the maximum clamping position (PSM) and the stripping position (POEV).

The crimping pliers according to claim 5, wherein the intermediate clamping position (P $ n, P $ i2, Ps *) is in relation to the zero clamping position (Pso). between 20% and 80% of the maximum clamping position, preferably between 60% and 40% of the maximum clamping position, preferably at 50% of the maximum clamping position.

The crimping pliers according to any one of claims 3 to 6, wherein a length (L1) of the oblong slots (1 14-1 15) is selected so that the guide pins (112-1 13) abut with a front end (114a-115a) oblong slots (114-115) at the end of crimping.

The crimping pliers according to any of claims 3 to 7, wherein the locking pawl (110) further has:

A contact surface (110b) with the push pawl (109); and

A contact surface (1 10c) with the hollow upper end (107a) of the pivoting handle (107),

said contact surfaces (110b, 110c) being arranged to disengage the cross member (110a) of the locking pawl (1 10) together with the cross member (109a) of the pawl (109) when the pivoting handle is rotated to the stripping position.

9. Method of crimping two pieces together, such as sheets, comprising:

a) The supply of both pieces;

b) positioning the two parts in a crimping position;

c) The provision of a crimping tool according to ^one of Claims 3 to 9;

d) the positioning of the front end of the hollow body behind the parts with reference to the pushing direction of the rack, said rack being in an initial position (Pi);

e) The stepwise pushing of the rack towards the two parts by successive tightenings of the pivoting handle towards the fixed handle, with a clamping force less than a clamping force necessary for the punching of the pieces, until the punch is in a contact position (Pc) with a first of the two pieces;

The method of crimping according to the preceding claim when implementing a clamp according to claim 5, wherein, in step e), the pivoting handle is in an intermediate position (Psn, Psis, Psis) between the zero clamping position (Pso) and the maximum clamping position (PSM) when the punch is in the contact position (Pc) with a first of the two pieces.