U.S. patent application number 09/988406 was filed with the patent office on 2002-05-23 for process and device for notching a frame tube for an automobile vehicle seat, and more particularly a headrest support tube.
This patent application is currently assigned to FAURECIA SIEGES D'AUTOMOBILE S.A.. Invention is credited to Richard, Joly.
Application Number | 20020060489 09/988406 |
Document ID | / |
Family ID | 8856638 |
Filed Date | 2002-05-23 |
United States Patent
Application |
20020060489 |
Kind Code |
A1 |
Richard, Joly |
May 23, 2002 |
Process and device for notching a frame tube for an automobile
vehicle seat, and more particularly a headrest support tube
Abstract
To make a notch in a tube, and more particularly a headrest
support tube, with the notch featuring at least one locking edge
perpendicular to the longitudinal direction (A) of the tube and
forming a square angle with the external surface of the tube, the
tube is gripped between clamping jaws, a punch is guided across the
jaws in a working direction (B) that converges with the axis (A) of
the tube and is angled with respect to said axis by a working angle
(.alpha.1) of between approximately 15.degree. and approximately
45.degree.. The tip of the punch features a tooth with a working
face, an angled rear face, and a front face joining the working
face to the rear face, with the working face and the front face
forming a working edge, and a suitable punching force is applied to
the punch to make the tooth penetrate the tube wall in said working
direction, until said working edge has penetrated the tube by a
radial distance equal to the depth of the notch to be produced.
Inventors: |
Richard, Joly; (Longuyon,
FR) |
Correspondence
Address: |
CONNOLLY BOVE LODGE & HUTZ LLP
SUITE 800
1990 M STREET NW
WASHINGTON
DC
20036-3425
US
|
Assignee: |
FAURECIA SIEGES D'AUTOMOBILE
S.A.
Boulogne
FR
|
Family ID: |
8856638 |
Appl. No.: |
09/988406 |
Filed: |
November 19, 2001 |
Current U.S.
Class: |
297/391 |
Current CPC
Class: |
B21D 22/04 20130101 |
Class at
Publication: |
297/391 |
International
Class: |
A47C 007/36 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 20, 2000 |
FR |
00 14920 |
Claims
1. Process for notching a support tube (1) for an automobile
vehicle seat, and more particularly a headrest support tube, by
which at least one notch (12) is made in the tube, this notch
featuring at least one locking edge (13) perpendicular to the
longitudinal direction (A) of the tube and forming a sharp edge
with the external surface of the tube, characterized in that: the
tube (1) is gripped in the area surrounding the notch to be formed
between clamping jaws (51, 52) defining a cylindrical clamping
surface (53, 54) enclosing the periphery of the tube, a punch (6)
is guided across the jaws in a working direction (B) that converges
with the axis (A) of the clamping surface and is angled with
respect to the said axis at a predetermined working angle
(.alpha.1) of between approximately 15.degree. and 45.degree., with
the tip (63) of the punch featuring a notch forming tooth (21) with
a working face (22) parallel to the locking edge of the notch to be
made, a rear face (24) that extends along a plane inclined with
respect to the tube axis, and a front face (23) joining the working
face and the rear face, with the intersection between the working
face and the front face forming a working edge (25), and a punching
force is applied to the punch such that the tooth (21) penetrates
the tube wall in the said working direction until the working edge
has penetrated the tube by a radial distance equal to the depth of
the notch to be produced.
2. Process in accordance with claim 1, characterized in that the
working angle (.alpha.1) is between 30.degree. and 40.degree..
3. Process in accordance with claim 1, characterized in that the
angle (.alpha.3) of the rear face (24) with respect to the said
working direction (B) is between 0.degree. and the said working
angle (.alpha.1).
4. Process in accordance with claim 1, characterized in that to
make a notch (18) featuring two square edges, the notch forming
operations are repeated by reversing the working angle
symmetrically with respect to a plane orthogonal to the tube axis,
and such that in the second operation the front face (23) of the
tooth reaches the bottom of the notch (18) formed by the front face
during the first forming operation.
5. Process in accordance with claim 4, characterized in that the
forming of the notch bottom is finished using a punch (33) that
moves perpendicularly to the tube axis and whose end face profile
corresponds to the desired form of the bottom of the notch
(18).
6. Device for notching a support tube for an automobile vehicle
seat, and more particularly a headrest support tube, characterized
in that it comprises: clamping jaws (51, 52) defining a cylindrical
clamping surface (53, 54) enclosing the periphery of the tube (1),
to grip the tube in the area surrounding the notch (12) to be made,
a punch (6) guided across the jaws in a working direction (B) that
converges with the axis (A) of the clamping surface and is angled
with respect to the said axis at a predetermined working angle
(.alpha.1) of between 15.degree. and 45.degree., with the tip of
the punch featuring a notch forming tooth (21) with a working face
(22) parallel to the locking edge of the notch to be made, a rear
face (24) that extends along a plane inclined with respect to the
tube axis, and a front face (23) joining the working face and the
rear face, with the intersection between the working face and the
front face forming a working edge (25), control means (42) to apply
a suitable punching force to punch (6) to make tooth (21) penetrate
the tube wall in the said working direction.
7. Device in accordance with claim 6, characterized in that the
working face (22) of the tooth (21) of the punch (6) forms an angle
(.alpha.2) of between 70 and 100.degree. with the axis (A) of the
clamping surface (53, 54).
8. Device in accordance with claim 6, characterized in that the
rear face (24) of the tooth (21) of the punch (6) forms an angle of
between 0.degree. and the value of the working angle (.alpha.1)
with the axis (A) of the clamping surface.
9. Device in accordance with claim 6, characterized in that the
clamping jaws comprise a fixed jaw (52) and a moving jaw (51)
perpendicular to the axis (A) of the tube and controlled by a
clamping actuator (43).
10. Device in accordance with claim 9, characterized in that one of
the jaws is made in contiguous two sections (52a, 52b) and features
a hole to guide the punch (6), formed by the combination of two
grooves (56) made in the two sections of the jaw, in the joining
plane (55) between the said two parts.
11. Device in accordance with claim 10, characterized in that the
tooth (21) protrudes with respect to an end face (64) of the punch,
the said end face meeting the clamping surface at a tangent when
the punch reaches end of travel after the drawing operation.
12. Device in accordance with claim 11, characterized in that the
end face (64) has a concave profile corresponding to the clamping
surface.
13. Support tube (1) for an automobile vehicle seat, and more
particularly a headrest frame tube, characterized in that it is
provided with sharp angle notches (12) obtained by the process in
accordance with one of claims 1 to 5, without removing material and
without deforming the external cross-section of the tube.
Description
[0001] This invention concerns a process and device for making
notches in a support tube for an automobile vehicle seat, and more
particularly a headrest frame tube.
[0002] It concerns more particularly, but not exclusively,
height-adjustable headrest supports featuring several notches
spaced along the length of at least one support tube, with each
notch determining a position setting. One conventional type of
headrest has a frame formed for example by a tube bent into an
inverted U shape, with each branch of the U forming a supporting
rod that can slide into a guide in the seat back, so that the
headrest can be set in the position desired by the seat occupant.
The chosen position is commonly maintained by means of blocking
systems, such as a spring clamp that engages in the notches of one
or both headrest supporting rods.
[0003] Moreover, to prevent the headrest from moving downwards if a
strong force is exerted on it by the occupant's head, in the event
of an accident for example, it is known to make the adjustment
notches with an upper edge that is approximately orthogonal to the
longitudinal direction of the headrest support rod, to form a
positive stop to prevent the headrest from sliding downwards,
unless the headrest is intentionally released. The lower edge of
the notch is preferably beveled to facilitate upward movement of
the headrest, without being blocked by the locking clamp.
[0004] Equally, a far-end bottom notch can be made with square
lower edge to form a positive stop that prevents accidental removal
of the headrest from its guides when pulled upwards, unless it has
been intentionally released.
[0005] As can be seen on the headrest support tube shown in FIG. 1,
it is possible to have several notches situated towards the front
or the rear of the headrest, and these notches can, depending on
the intended application, have several different configurations: a
square upper edge and beveled lower edge or a square lower edge and
beveled upper edge, or two square edges.
[0006] These notches can easily be created in solid metal rods by
punching or drawing. It is however desirable to make tubular
headrest supports to reduce weight. The creation of notches in a
tube by transverse drawing inevitably deforms the tube through
crushing. This process does not produce the desired square-edged
notch faces, where the desired result is to have a square edge that
is as sharp as possible.
[0007] To try to solve this problem, the machining of a previously
drawn preform has already been proposed. However, apart from the
additional cost of machining, this method removes material and
therefore weakens the tube at the notches.
[0008] It has also been proposed, for example in document DE
29714315, to introduce a metal sleeve or rod into the part of the
tube in which the notches are to be formed, in order to locally
fill the tube and enable the notches to be produced by drawing, as
would be done with a solid rod. However, this added sleeve
increases the weight and moreover it must be positioned correctly
inside the tube prior to the drawing operation, and this creates
additional problems.
[0009] It has also been proposed to produce the notches by
hydroforming, but this method requires specific and extremely
costly equipment to generate the very high pressures required.
[0010] From document EP 974409, we also know of a method of making
square edged notches in tubes without removing material, and that
method aims at keeping virtually constant the tube wall thickness
at the notches and the arrangement of the metal fibres, without
deforming the tube around the notches. This method consists in
using a riveting machine fitted with a notch-forming tool. The
notch is then produced by the hammering of the machine, which leads
to progressive shaping of the notches, allowing the production of
relatively sharp angled edges due to the fact that each blow of the
tool deforms the material very locally and by a small amount. The
disadvantage of this process however is that it takes a relatively
long time to produce each notch.
[0011] The aim of the present invention is to solve the problems
mentioned above and to provide a tube notching machine and a
process that is easy to implement and allows sharp edged notches to
be made in tubes in an economical manner. It aims more specifically
at producing on tubes, usually with a more or less circular
cross-section, notching in which at least one face of the notches
makes a sharp square angle with the external surface of the tube
wall. It aims at producing these notches without removing material
and without deforming the external cross-section of the tube, in
particular to avoid disturbing the sliding of the tube in a
guide.
[0012] It also aims at obtaining the said notching without
excessive reduction in the tube wall thickness at and around the
notch, by seeking to satisfy the desire to maintain a virtually
constant or even increased thickness at the bottom of the notch, to
ensure optimum mechanical strength of the support should the
notches be subjected to high loads.
[0013] The invention aims more particularly, but not exclusively,
at producing notches commonly called anti-collapse or anti-ejection
notches in a headrest support, while benefiting from the low weight
that can be obtained by making the said support from a tube, and
without reducing the strength and reliability of this support.
[0014] With these objectives in view, the subject of the invention
is a process for notching a support tube for an automobile vehicle
seat, and more particularly a headrest support tube. It is a
process that makes at least one notch featuring at least one
locking edge perpendicular to the longitudinal direction of the
tube, and forming a sharp edge with the external surface of the
tube.
[0015] In accordance with the invention, this process is
characterized in that:
[0016] the tube is gripped, in the area around the notch to be
formed, between clamping jaws that form a cylindrical clamping
surface enclosing the periphery of the tube,
[0017] a punch is guided across the jaws in a working direction
that converges with the axis of the clamping surface and is angled
with respect to the said axis at a predetermined working angle of
between approximately 15.degree. and approximately 45.degree., with
the tip of the punch featuring a notch forming tooth with a working
face parallel to the locking edge of the notch to be made, a rear
face that extends along a plane angled with respect to the tube
axis, and a front face joining the working face and the rear face,
with the intersection of the working face and the front face
forming a working edge,
[0018] and a suitable punching force is applied to the punch to
make the tooth penetrate the tube wall in the said working
direction, until the working edge has penetrated the tube by a
radial distance equal to the depth of the notch to be produced.
[0019] Thus, by means of the process in accordance with the
invention, and in particular due to the angle of the direction of
movement of the punch with respect to the tube axis, the desired
type of notch can be made in the tube, that is to say forming a
sufficiently sharp angle with the outer surface of the tube, simply
and rapidly in a single drawing operation.
[0020] As a general rule, when the headrest is used, the sharp
square edge of notch in the rod works in conjunction with the
locking device to ensure reliable locking of the headrest. To
achieve this the angle this square edge makes with the axis of the
headrest support rod axis is about 90.degree., that is to say for
example between 80.degree. and 100.degree.. But, to make locking
even more reliable, this edge can even form an acute angle with the
generating surface of the rod in which the notch is made, for
example down to 70.degree. or even less. Such an acute angle which
would be difficult to obtain with the known processes can, on the
contrary, be easily produced by the process in accordance with the
invention.
[0021] The working angle of between 15 and 45.degree., and
preferably between 30.degree. and 40.degree., means that the tool
penetrates the tube metal in a direction that is sufficiently
angled to avoid any crushing of the tube, or at least negligible
crushing compared with that which would occur if punching was
carried out perpendicular to the tube axis. When the working edge
penetrates the tube metal, the metal is upset towards the tube
interior, but because the pressure is exerted in a direction
relatively close to the axial direction of the tube, the effect of
upsetting towards the interior is relatively less than the effect
of pushing metal in the axial direction produced by the working
face of the punch.
[0022] With regard to this, the importance of all-round clamping of
the tube must be stressed, not simply to prevent axial movement
under the punching force, but also to prevent tube deformation by
swelling around the punched zone.
[0023] The working edge is straight, insofar as the working face
and the front face are both flat, to form a notch locking edge and
bottom that are also flat. One could nevertheless in a similar
manner produce notch edges and bottoms that are not flat, by
adapting the shape of the punch working and front faces to the
desired notch edge shapes.
[0024] It will also be noted that the working edge is preferably
rounded with a radius of less than 0.8 mm, and more preferably of
about 0.2 mm. The rounding of the working edge means that it does
not shear the drawn metal, but on the contrary tends to upset it
under the front face, with the rounded edge "sliding" over the
deformed zone as the tool advances.
[0025] The angle of the rear face with respect to the working
direction is preferably between 0.degree. and the said working
angle, and more preferably about 20.degree.. The value of this
angle has two effects. Firstly, it determines the angle of the
notch edge opposite the square edge, and must therefore respect the
constraints of the locking system in order not to hinder movement
of the headrest in the authorized direction, as was indicated
previously. Secondly, the angle of the rear face influences the
drawing operation itself. This is due to the fact that, depending
on the value of this angle with respect to the direction of punch
travel, the rear face of the punch tooth has a more or less marked
direct drawing effect. For example, if the angle is 0.degree., the
rear face of the tooth will simply slide against the angled portion
of the edge formed by the working face, without causing any
specific deformation. If, on the contrary, the angle is relatively
steep, and in particular if it approaches the working angle, the
rear face will firstly participate directly in the deformation of
the metal by pushing back the portion of the tube wall that will
form the said beveled edge, and secondly, by the resulting reactive
force, it will tend to push the punch forward, that is to say in
the punch advance direction.
[0026] It is the combination of the effects of these different
angles that finally enables the notch to be formed without crushing
the tube around the said notch, thereby forming the squarest angle
possible between the locking edge and the cylindrical wall of the
tube.
[0027] The front face of the tool is preferably flat and more or
less parallel with the axis of the clamping surface, to form a
notch bottom that is more or less parallel with the tube axis. If
necessary however, this face could be made with a predetermined
form and in particular with a certain angle with respect to the
tube axis. The front face could even be virtually eliminated, or
blended with the rear face as it were, forming in this case a notch
with a triangular profile.
[0028] In accordance with a particular arrangement of the
invention, to make a notch featuring two square-angled edges, the
notch forming operations are repeated, reversing the working angle
symmetrically with respect to a plane orthogonal to the tube axis,
and such that during the second operation the front face of the
tooth reaches the bottom of the notch formed by the front face
during the first forming operation.
[0029] If the front face of the tooth is small in comparison with
the notch length, after the preceding two operations there may
subsist an insufficiently drawn median area in an intermediate zone
between the two formed parts of the notch. In this case the forming
of the notch bottom can be completed with a punch moved
perpendicularly to the tube axis and whose end face is shaped
according to the desired form of the notch bottom.
[0030] A single set of clamping jaws and punch can be used to make
several notches in the tube, one after the other, by moving the
tube in the clamping jaws from one position to the next using an
automated positioning device, for example. It is also possible to
make several notches on the tube simultaneously using a machine
equipped with several punches.
[0031] The subject matter of the invention also concerns a support
tube for an automobile vehicle seat, and more particularly a
headrest support tube, characterized in that it is provided with
square-edged notching obtained by the process mentioned above,
without removal of material and without deforming the external
cross-section of the tube
[0032] The subject matter of the invention further concerns a
device for notching a support tube for an automobile vehicle seat,
and more particularly a headrest support tube, characterized in
that it comprises:
[0033] clamping jaws defining a cylindrical clamping surface
enclosing the periphery of the tube, to clamp the tube in the zone
surrounding the notch to be formed,
[0034] a punch guided across the jaws in a working direction that
converges with the axis of the clamping surface and is angled with
respect to the said axis at a predetermined working angle of
between approximately 15.degree. to 45.degree., with the tip of the
punch featuring a notch forming tooth with a working face parallel
to the locking edge of the notch to be made, a rear face that
extends along a plane angled with respect to the tube axis, and a
front face joining the working face and the rear face, with the
intersection of the working face and the front face forming a
working edge,
[0035] means of control to exert a suitable punching force on the
punch to make the tooth penetrate the wall of the tube in the said
working direction.
[0036] In accordance with other particular arrangements:
[0037] the working face of the punch tooth forms an angle of
between 70 and 100.degree. with the axis of the clamping
surface.
[0038] the rear face of the punch tooth forms an angle with the
axis of the clamping surface of between 10.degree. and the value of
the working angle.
[0039] the clamping jaws comprise a fixed thrust jaw and a mobile
clamping jaw perpendicular to the tube axis, controlled by a
clamping jack.
[0040] one of the jaws is made in two contiguous sections, and
features a punch guiding hole formed when two grooves, one in each
section, are brought together in the joining plane between the two
sections of the said jaw. This method of fabrication enables, for
example, a rectangular cross-section guiding hole to be created to
accommodate the sliding movement of a punch whose end part has a
similar rectangular cross-section, thus providing a simple means of
making the tool and clamping jaws while preventing any pivoting of
the punch around its axis.
[0041] the forming tooth is made such that it protrudes beyond one
end face of the punch, with the said end face meeting the tube at a
tangent at the end of punch travel. The end face can also have a
concave profile corresponding to the external surface of the tube,
in order to envelop the tube around the notch when forming of the
said notch is completed, in order to push back any points of local
swelling that might have appeared further to the drawing operation,
to ensure that at the end of the operation there is no increase in
the tube cross-section at any point whatsoever.
[0042] Other characteristics and advantages will come to light in
the following description of a device and process for notching a
headrest support tube, in accordance with the invention.
[0043] Refer to the appended drawings in which:
[0044] FIG. 1 is a perspective view of a tubular headrest support
made by the process forming the subject of the invention,
[0045] FIG. 2 is a schematic diagram of the process forming the
subject of the invention to make a notch in such a support,
[0046] FIG. 3 is another diagram illustrating the creation of a
notch featuring two opposing square edges orthogonal to the axis of
the tube,
[0047] FIG. 4 is a simplified view of a machine in accordance with
the invention for making notches in a tubular support,
[0048] FIG. 5 is a longitudinal section view of the drawing
punch,
[0049] FIG. 6 is a front view of the punch viewed in the direction
of arrow F1 of FIG. 5,
[0050] FIG. 7 is a view of the end of the punch in the direction of
arrow F2 of FIG. 5,
[0051] FIG. 8 is a partial perspective view of the end of the
punch,
[0052] FIG. 9 is a perspective view of the tube clamping jaws,
[0053] FIG. 10 is a front view of the jaws clamping the tube during
the drawing operation.
[0054] The headrest support 1 illustrated in FIG. 1 is made from a
steel tube, for example type E36 steel, with a tensile strength of
400 MPa and an elongation of 22%, diameter 14 mm and thickness 2
mm. The tube is bent to form a U-shape with two branches 11
constituting the headrest support and guiding rods, which slide and
can be locked in a manner known in itself in the guides built into
the back of an automobile seat. Each rod comprises notches 12,
which have a square upper edge situated in a plane more or less
perpendicular to the rod axis, a bottom 14 that is more or less
flat and parallel to the axis, and a lower edge 15 that is slightly
beveled with respect to the said axis. On one of the branches we
have also shown a notch 16 in the same direction but situated on
the diametrically opposed side of the tube, and a lower notch 17,
which is reversed with respect to the other notches. The notch
arrangement shown in FIG. 1 is given purely for illustrative
purposes and is in no way limiting.
[0055] FIG. 2 provides a schematic illustration of the forming of a
notch like notch 12, by a punch 2 moving in the direction of its
axis B which is angled at a working angle .alpha.1 with respect to
the tube axis, of 35.degree. for example, and whose end forms a
tooth 21 displaying:
[0056] a working face 22 situated in a plane forming an angle
.alpha.2 of between 70.degree. and 100.degree. with respect to the
axis A of tube 1, this angle being 90.degree. in the example
illustrated.
[0057] a front face 23, more or less parallel with axis A,
[0058] a rear face 24, angled with respect to axis B by an angle
.alpha.3 of between 0.degree. and the value of angle .alpha.1.
[0059] The notch 12 is made by pushing the punch 2, by means of a
hydraulic actuator for example, in the direction of arrow F, until
the edge 25 formed by the intersection of the working face 22 and
the front face 23 has penetrated the tube by a radial distance
equal to the desired depth of the notch. This edge is rounded with
a radius of less than 0.8 mm, and preferably a radius of 0.2
mm.
[0060] As the punch advances, the edge 25 penetrates the metal wall
of the tube in the direction of arrow F, with the working face 22
gradually pushing back the metal in front of it to form the square
edge 13 at end of travel, while at the same time allowing the said
metal to flow towards the front face 23, which forms the bottom 14
of the notch at end of travel. At the same time, the beveled edge
15 is formed by the rear face 24 of the tooth.
[0061] In the case shown in FIG. 3, the notch 18 with two square
edges is made in two successive operations, the first being
illustrated by the dashed line 31 of the tool, angled with respect
to the tube axis by the angle .alpha.1 to form the first square
edge 18', and the second, illustrated by the solid line 32, angled
symmetrically with respect to a plane orthogonal to the tube axis,
to form the second square edge 18". To finish the bottom of the
notch, a third drawing operation can be carried out by a tool 33
that moves perpendicularly to the tube.
[0062] The machine illustrated in FIG. 4 features a frame 40
comprising a punching head 41 and a clamping assembly that moves
vertically with respect to frame 40 and is controlled by a clamping
actuator 43. Frame 40 bears fixed clamping jaws 52, such as those
illustrated in FIGS. 9 and 10 which will be described later. The
moving clamping assembly features moving clamping jaws 51. The
punching head features an axially guided punch 6 controlled by a
hydraulic actuator 42. One end of the punch passes through the
clamping jaws 52, which guide its sliding movement in the working
direction F and prevent it from rotating.
[0063] The punch 6 used in the machine in FIG. 4 is illustrated in
FIGS. 5 to 8. It comprises a body 61, of which one end 62 is
arranged in a known manner to be connected to the control actuator
42. Towards the other end, the body features a rectangular
cross-section guiding section 63 terminated by an end face 64,
angled along a working angle .alpha.1=35.degree. with respect to
axis B of the punch. The notch-forming tooth 21 protrudes with
respect to face 64 and extends over its entire width, for example
11 mm, this width being determined such that it corresponds to the
width of the finished notch.
[0064] The clamping jaws illustrated in FIG. 9 in a reversed
position with respect to the illustration in FIG. 4, comprise a
moving jaw 51 and a fixed jaw 52 made in two sections 52a and 52b
separated by a joining plane 55. The moving jaw 51 is attached to
the moving clamping assembly and the fixed jaw 52 is attached to
frame 40 of the machine.
[0065] Jaw 51 features a semi-cylindrical recess 53, and each
section of the fixed jaw 52 features a quarter-cylinder recess 54,
such that when the two sections of jaw 52 are assembled together in
the joining plane 55 and the moving jaw is brought opposite the two
assembled sections of the fixed jaw, the surfaces of the recessed
forms 53 and 54 constitute a cylindrical surface of the same
cross-sectional area as the tube 1, that is capable of clamping the
said tube firmly under the action of clamping actuator 43, to
completely immobilize it when the notches are being formed.
[0066] The rectangular section of the punch is guided in a hole
with the same cross-section, made up by the combination of two
grooves 56, one in each respective section of the fixed jaw 52,
with the rectangular cross-section preventing any risk of the punch
pivoting around its axis.
[0067] The way in which the machine is used to make a notch can be
easily deduced from the foregoing. As the moving jaw 51 is lifted
by the actuator 43, the tube 1 has simply to be placed in the
recess in the lower jaw. The tube is then gripped by actuating the
clamping actuator 43. Then actuator 42 that drives the punch is
activated in order to make the punch tooth penetrate the tube wall
down to the desired depth, which is usually defined by the height
of the tooth, which therefore corresponds to bringing the face of
punch end 64 tangential with the tube. Punch withdrawal is then
initiated, the jaws are separated, and the tube can be moved along
to make another notch, or another tube can be installed.
[0068] The invention is not limited to the method of production
described above solely by way of example.
[0069] In the illustrated example, the end face 64 is flat, which
facilitates the creation of the active end of the punch. This face
can also be given a concave form to better match the external
surface of the tube, as has already been explained.
[0070] The shapes and dimensions of the guided end of the punch and
tooth can also be modified to adapt them to the tube dimensions and
materials, while still remaining within the scope of the
invention.
* * * * *