Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Pressina tool for Dressina a cylindrical pressina
member or a pressina member comprisin~ a cYlindrical
Dortion onto a round Drofile. particularlY a pipe
conduit
The invention is directed to a pressing tool for press-
ing a cylindrical pressing member or a pressing member
comprising a cylindrical portion onto a round profile,
particularly a pipe conduit, comprising a plurality of
press dies for pressing the pressing member onto the
;~ round profile from all sides in a pressing process,
and further comprising a plurality of holding members
provided with receiving portions for holding the press
dies, at least one of said holding members being adapt-
ed to be moved towards the other holding member(s) and
away therefrom, respectively.
Pressing tools of the above type are used for estab-
lishing press connections between pipe conduits and
connector pieces, so-called fittings, for connecting
cable shoes or connectors to conductors (full profiles)
and for similar uses. The term "round profile" as used
; throughout this application is meant to cover both
hollow profiles and full profiles. A full profile, for
~ ~ instance, can also be a wire rope.
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For connecting a round profile by pressing action to a
connector piece of a random type, e.g. to a cable shoe,
a cable connector or a pipe conduit fitting, a substan-
tially cylindrical pressing member is pressed onto the
round profile. In a connection for a pipe conduit, the
pressing member can be e.g. a pressing shell enclosing
the pipe conduit. In a cable connector, the cable con-
nector itself serves as a pressing member; in a cable
shoe, the cylindrical portion thereof, provided for
receiving the end of the cable, constitutes the press-
ing member. The pressing tools utilized for effecting
the press connection, being pressing pliers or pressing
tools to be driven hydraulically or by a motor, com-
prise a plurality of press dies for pressing the press-
ing member onto the round profile from all sides in a
pressing process. In case of a hexagonal pressing tool,
for instance, two pressing dies are provided. Normally,
the pressing dies are fastened on two holding members
provided with receiving portions for holding the press
dies. In pressing pliers, the two arms of the pliers
form the holding members for holding the press dies; in
a pressing tool having one holding member to be dis-
placed in linear fashion, this holding member is pro-
vided as a longitudinally displaceable slider adapted
for movement towards a usually bracket-like holding
member and away therefrom.
The pliers known from DE 91 03 264.4 U1, designed for
establishing pipe connections by pressing action, are
provided with three press dies. Two of these press dies
are supported on the arms of the pliers while the third
press die is arranged in stationary manner between the
arms of the pliers. The arms of the pliers are pivot-
able about rotational axes extending in parallel to
each other, wherein, when the pressing pliers are
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closed, the two press dies arranged on the~arms of the
pliers move towards each other and in the direction of
the stationary press die, while in their final pressing
position they are arraged in mutual abutment and form a
ring enclosing the pressing member. Since, during the
closing of the pressing pliers, the movement of the
press dies does not progress radially but - because of
the pivoting of the arms of the pliers about the rota-
tional axes - along an arc in the direction of the
pressing member, the pressing effect is not yet opti-
mal. Especially for the pressing of ends of pipe con-
duits onto fittings, high demands are posed to the
tightness of the connection. These high demands regard-
ing the tightness of the pipe connection cannot be met
even by hexagonal pressing tools (no matter whether
they are operated hydraulically or manually). The two
press dies of a hexagonal pressing tool have different
pressing faces so that the pressing has a slightly oval
configuration. Also a hexagonal pressing tool suffers
from the problem that those pressing faces which do not
extend transversely to the moving direction of the
press dies, do not move toward the pressing member in
radial manner.
It is the object of the invention to provide a pressing
tool, particularly for establishing a press connection
between pipe conduits and fittings, which allows a
press connection with a reliable sealing effect while
requiring only small constructional effort.
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For solving the above object, there is provided a
pressing tool of the initially described type which is
characterized in that each pressing die is guided in
its receiving portion to be displaced in a direction
extending at an angle other than 0 with respect to the
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direction of the force acting on the press dies during
the pressing process for pressing the press dies
against the pressing member, that the holding members
move each of the press dies in a direction extending at
an angle other than 0 with respect to the radial ex-
tension of the pressing member, and that the press dies
prior to the pressing process can be moved into a
starting position in which they have a defined distance
from each other in circumferential direction, wherein,
during the pressing process, the press dies, because of
the displacement in their receiving portions and the
movement of the holding members towards each other,
approach each other until reaching a final pressing
position.
In general terms, the press dies of the pressing tool
of the invention are supported and guided on the hold-
ing members in displaceable manner so that, during the
pressing, the pregs dies move radially towards the
pressing member also if the holding members are not
moved radially with respect to the pressing member but
at an acute angle to the radial extension of the press-
ing member. Each of the holding members can have one or
a plurality of press dies supported thereon. Especially
when a plurality of press dies are supported on a hold-
ing member, a problem resides in that the press dies,
if fastened in stationary manner on the holding member,
cannot be moved radially towards the pressing member
during the pressing process. The displaceable support
of the press dies provided by the invention allows a
centric guidance of the press dies radially towards the
pressing shell.
Preferably, it is provided that each of the holding
members has supported thereon two press dies arranged
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substantially at a right angle with respect to each
other and displaced at a rotational angle of substan-
tially 45 with respect to the moving direction of the
at least one holding member, and that the press dies
are guided for displacement in their receiving portions
at an angle of substantially 45 with respect to the
moving direction of the at least one holding member.
In this arrangement of the pressing tool, a total of
four press dies are provided, which are supported on
only four holding members. The holding members are
e.g. the two arms of pressing pliers or the slider and
the opposite fixed abutment of an e.g. hydraulically
operated pressing head. The two press dies of each
holding member are supported in such a manner thereon
that they are displaced substantially by 90 with
respect to each other while being arranged in mirror
symmetry to an imaginary axis extending in moving
direction, i.e. are oriented at an angle of about 45
to the moving direction. All of the press dies are
guided to be displaced on the holding members; thus,
the press dies can be displaced in a direction which
during the pressing process forms an acute angle other
than 0 with the moving direction of the press dies.
For making this possible, the press dies can be moved
prior to the pressing process into a starting position
wherein they have a defined circumferential distance
from each other. The press dies are resiliently biased
into the starting position. In the subsequent pressing
process, the press dies, due to the movement of the two
holding members towards each other and the displacement
in the receiving portions within the holding members,
are moved towards each other until they rnaintain their
final pressing position in which the~- preferably abut
each other. In the final presing position, all of the
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press dies form a ring enclosing the pressing member.
Due to the displaceability of the press dies within the
receiving portions of the holding members, it is ac-
complished that the pressing faces of all press dies
move radially to the pressing member although there are
provided more pressing members than holding members for
holding them, which perform merely a movement towards
each other. Thus, movement of the pressing faces rela-
tive to the portions of the circumferential surface of
the pressing member which abut on the pressing faces,
is largely avoided so that a "clean~ pressing with a
sealing connection between the pipe conduit and the
fitting is generated.
The requirements for a press connection of cable shoes
and connectors with conductors are comparable to the
sealing requirements of a pipe conduit connection in so
far as a positive and a non-positive connection between
the conductor and the cable shoe or the connector is to
be generated. Also this requirement, which of course
also applies to pipe conduit connections, can be ful-
filled with the pressing tool of the invention so that
the range of applications of the pressing tool is not
restricted solely to pipe conduit connections.
In an advantageous embodiment of the invention, it is
provided that the pressing faces of the press dies are
arranged in such a manner that, while the press dies
are in their starting positions, the pressing faces can
already be brought into contact with the pressing mem-
ber to be pressed. As a matter of logic, this contact
cannot be performed over the complete pressing face
because the radius of the convex pressing faces is
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smaller than the radius of the pressing member prior to
pressing. Since, however, the difference between the
radii is relatively small and lies preferably in the
range of about 1 mm, the pressing faces are practically
in abutment with the circumferential surface of the
pressing member. Thus, from the beginning of the
pressing process, the pressing force can be applied
on all sides over the entire circumferential surface of
the pressing member in the region of the press dies.
This also improves the pressing effect.
Generally, the shape of the pressing faces can be se-
lected at random. For instance, the press dies can be
provided with smooth inner or pressing faces directed
towards each other. Preferably, it is provided that the
press dies have line-shaped concave pressing faces.
Preferably, these are generated in that grooves are
machined into the smooth concave pressing face of each
of the press dies, resulting in linear raised portions
extending in parallel to each other. Preferably, the
line-shaped pressing faces or protrusions are arranged
at distances from each other when the press dies are
located in their final pressing position with their
radial side faces abutting each other. The line-shaped
pressing faces cause a constriction of the elastically
deformable pressing member. For instance, the total
pressing face consists of the inner faces of three
rings formed by the protrusions on the mutually facing
inner faces of the press dies. Undesired crushing of
the material of the pressing member in the region be-
tween successive pressing faces of adjacent press dies
will not occur during pressing because, due to the
interior mechanical stress between the constricted por-
tions and the bellied portions, the material in this
region "flows off" towards the bellied portions.
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Preferably, the line-shaped pressing faces are ad~usted
to the configuration of the fitting with respect to the
relative position of the protrusions of the press dies.
Normally, a pipe conduit fitting comprises a support
body onto which the end of a pipe sondui~ is mounted,
and a pressing shell surrounding the end of the pipe
conduit. When using press dies with the above described
pressing faces, the support body of the fitting is pro-
vided with peripheral beads which are axially displaced
with respect to the protrusions of the pressing faces
of the press dies.
Each of the holding members comprises receiving por-
tions for the press dies. Preferably, the receiving
portion for a press die is provided in such a manner
that the press die on its side opposite the pressing
surface comprises an adapter piece or projection which
can be inserted into a receiving recess on the holding
member and be displaced therein. The width and the
depth of a receiving recess are substantially identical
with the thickness or the projecting length of the pro-
jection of the press die; the length of a receiving
recess, however, is larger than the length of the pro-
jection by the extent of the possible displacement of
the press die. The press die, thus having its projec-
tion inserted into the receiving recess partially in
positive connection, is reliably held therein while
movement is still possible.
Preferably, the springs urging the press dies into
their starting positions are respectvely arranged be-
tween the mutually facing ends of the projections of
the two press dies supported on a holding member and
the faces of the receiving recesses located opposite to
these projection ends. The pressure springs urge the
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two press dies of a holding member away from each other
so that these - while pressing against a pressing mem-
ber without a load, i.e. without pressing force - are
spaced from each other. The pressure springs are held
in blind-end bores of the pro~ections of the press
dies.
Preferably, the press dies are lockingly inserted into
receiving recesses of the holding members; thereby, the
press dies can be easily exchanged for other press
dies, with each of the press dies held in reliable man-
ner.
With the above locking connection between the press die
and the appertaining receiving portion, the locking
elements are immersed in longitudinal locking depres-
sions formed in the inner faces of the recesses. This
arrangement can of course also be provided vice versa,
i.e. in that the locking elements are arranged on the
inner faces of the recesses and are immersed in the
longitudinal locking depressions of the press dies.
Thus, the locking elements also fulfill a guiding func-
tion for the displacement of the projections and thus
of the press dies relative to the respective holding
members within the receiving portions during displace-
ment upon pressing and thereafter during opening of the
pressing tool.
As already mentioned above, the pressing tool can be
provided in the form of pressing pliers wherein the
pressing dies are held on the two arms of the pliers,
or the pressing tool can be a tool comprising an
hydraulic, motor-driven or hand-driven pressing head
having a slider guided for linear displacement therein
for moving towards or away from a stationary abutment.
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In this arrangement, the slider and the abutment act as
the holding members for holding the press dies. The
pressing head can have e.g. C-shaped configuration with
or without a lockable and releasable bracket for clos-
ing the open side.
Preferably, the pressing head is arranged as a two-
armed fork having its fork basis connecting the two
arms. There is provided a slider acting as one of the
holding members, being guided for longitudinal dis-
placement relative to the two fork arms and carrying
two press dies on its end directed to the end of the
fork. The open side of the fork can be closed by a
bracket to be locked releasably. The bracket acts as an
abutment and is likewise provided with two press dies
which are located opposite to the press dies of the
slider. The bracket has both of its ends connected to
the fork so that the pressing forces acting on the arm
can be reliably received by the fork. Therefore, the
bracket can have smaller width than the portion of a C-
shaped pressing head acting as an abutment. Also in
restricted space conditions, e.g. in the region of dis-
tributors of underfloor heatings, pressing can still be
accomplished by the above arrangement.
Both holding members have their mutually facing sides
provided with V-shaped edge recesses or V-shaped por-
tions in whose regions the press dies are arranged.
When the holding members are in abutment with each
other, e.g. when the slider has been moved up to the
bracket, the V-shaped edge recesses or portions, with-
out the press dies, form a quadrangular opening which
is arranged at such a rotational displacement that the
diagonal line of the quadrangle coincides with the line
of application of the pressing force or extends in
parallel thereto. In a pressing head having a slider
provided for linear displacement, the diagonal line
extends in the moving direction of the slider.
Preferably, the locking point between the free end of
the bracket, averted from the pivot point with the one
fork arm and the other fork arm is located at a
position which, when viewing the bracket from the basis
of the fork, is arranged before the press dies or the
pressing member. This arrangement is advantageous
especially for the pressing of pipe conduits located
closely side by side to each other in a row, because
the distance of the individual pipe connections
canlatively small, notably slightly larger than the
thickness of the bracket, without hindering or
preventing the use of the tool of the invention. Also
the locking or release lever or the like is arranged
before the press dies.
Preferably, the slider is biased in the direction of
the open end of the fork so that the press dies after
the locking of the bracket abut the pressing member
with the force of the biasing spring. This provides for
a certain fixation of the pressing tool.
Preferably, the path of displacement of the slider in
the direction of the bracket is limited by guide pins
entering into guide recesses of the slider. Thus, it is
precluded that the slider slips out when the fork is
open. The guide pins projecting from the inner side
faces of the fork arm, which are immersed into the
guide recesses of the slider located opposite thereto,
also act as a linear guide means for the slider.
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For advancing the slider with the pressing force~re-
quired for the pressing, there is preferably provided a
plunger extending through a passage in the fork basis
and abutting the end of the slider averted from the
fork opening or being connected to the slider thereat.
The driving of the plunger for advancing it is per-
formed preferably hydraulically. Suitable manual
hydraulic drives are available on the market. The
pressing tool of the invention can be adapted to these
devices in that the fork can be screwed onto the de-
vices or can be coupled to the hydraulic drives in some
other manner (e.g. by snapping or bajonet locking).
Preferably, the slider can be completely disassembled
for exchanging it in a simple and uncomplicated manner
against another press die comprising differently de-
signed receiving portions for receiving pres~ dies hav-
ing a different shape. To this purpose, the slider com-
prises a preferably relatively flat, solid slider core
whose side edges, which are facing the inner sides of
the fork arms, comprise the guide recesses for receiv-
ing the guide pins. The guide grooves extend over the
whole thickness of the slider, i.e. they are provided
in the manner of edge recesses limited on three sides.
The receiving recesses for the projections of the press
dies are shaped in the same manner. All of the edge
recesses (guid1ng and receiving recesses) are limited
by slider plates in the planes of the upper and lower
sides of the slider core which enclose the slider core
from above and below and are connected thereto by
knurled screws or in some other manner allowing manual
release of the connection. For exchange of the slider,
it is merely required to release the screw connection
of one of a slider plate; the slider core along with
the second lsider plate can the be removed from the
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fork by movement transversely to the longitudinal dis-
placement of the slider.
Preferably, the slider plates project beyond the press
dies of the slider while, in this region, they are pro-
vided with a respective edge recess by which they
engage around the round profile upon application of the
pressing tool. This facilitates the positioning of the
pressing tool. ~he two edge recesses of the slider
plates are flush with each other and with the opening
enclosed by the press dies.
The edge recesses of slider plates are particularly
advantageous for a pressing action wherein the pressing
tool is to be reliably secured against axial displace-
ment relative to the round profile. The pressing member
or - in pipe conduit fitting - the support body,
comprises a peripheral shoulder having the edge of the
edge recess of the one slider plate axially abutting
thereon, while the edge of the edge recess of the other
slider plate is in abutment on the axial end of the
pressing member averted from the peripheral shoulder.
In this manner, the fixing of the pressing tool and the
pressing or the pipe conduit connector ~piece is ob-
tained. Alternatively, one of the two slider plate edge
recesses can be provided for setting it onto a pipe
conduit fitting having a circumferential groove machin-
ed into the peripheral shoulder or for bilateral en-
closure of a peripheral shoulder of a pipe conduit fit-
ting. All of these variants are designed for providing
not only a mechanical coupling of pressing tool and
pressing member but, through the press dies, a posi-
tional fixing of the pressing tool relative to the
round profile to be connected by press action.
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An embodiment of the invention will be~described here-
under in greater detail with reference to the drawings.
Fig. 1 shows a side view of a pressing tool screwed
onto a hand-operated hydr~ulic device;
Fig. 2 shows the pressing tool according to Fig. 1 at
an enlarged scale, with the press dies abutting
on a pressing member without pressing force,
and without a slider plate;
Fig. 3 shows a side view, similar to Fig. 1, of the
pressing tool, partially broken away and seen
in section, with the press dies being in their
final pressing position, and without the press-
ed pressing member;
Fig. 4 shows a side view of the pressing tool with a
slider plate and with the press dies in their
final pressing position;
Fig. 5 shows a frontal view of the pressing tool in
the direction of arrow V of Fig. 4 for illus-
trating the lateral enclosure of the bracket by
suitable edge projections of the slider plates
in the locking region of the bracket and the
fork;
Fig. 6 shows a sectional view along the line VI-VI of
Fig. 4;
Fig. 7 shows the press die receiving region of the
bracket designated by VII in Fig. 2 in horizon-
tal section;
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Fig. 8 shows a sectional view along the line VIII-VIII
of Fig. 7;
Fig. 9 shows a sectional view along the line IX-IX of
Fig. 7;
Fig. 10 shows a side view of the pressing tool with the
bracket in its open position, and
Figs. 11 and 12
show longitidinal sectional views of a first
and a second pipe conduit fitting, with the
press dies abutting on the pressing member
without pressing force.
Figs. 1 to 4 are side views of a pressing tool lO with
different positions of its individual elements. As
evident from Fig. 1, the pressing tool 10 i5 provided
as a pressing head screwed onto a hand-operated hydrau-
lic device 12. The hand-operated hydraulic device 12 is
provided with a fixed and a movable handle 14,16. By
upward and downward movement of the handle 16, hydrau-
lic liquid is pumped or pressurized within a housing 18
rigidly connected to handle 14, in order~to advance a
plunger 20 acting on pressing tool 10. The pressing
tool 10 is screwed in a known manner onto the housing
10 of the hand-operated hydraulic device 12, with a
stopper arm 22 limiting a twisting movement of the
pressing tool 10 relative to the hand-operated hydrau-
lic device 12 to a rotational angle of about 180.
The pressing tool 10 comprises a fork-shaped element 24
wherein a slider 26 is guided for longitudinal dis-
placement. The open side of fork 24 can be closed by a
bracket 28 having one end rotatably connected to one
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arm of the fork while its- other end is adapted to be
releasably locked to the other arm of the fork. The
locking of bracket 28 is effected through a locking arm
30 supported on fork 24.
The slider 26 comprises two slider plates 32 (Figs. 1
and 4 showing one of these slider plates, respectively)
and a slider core 34 arranged between the two slider
plates 32 (shown e.g. in Figs. 2, 3 and lO). In the
front end of slider core 34 facing towards bracket 28,
there is formed a V-shaped recess 36, extending sub-
stantially over the whole width of slider core 34, with
the edges 38 of its legs extending at a right angle to
each other and at an angle of 4S of the direction of
displacement (cf. the double arrow 40 in Fig. 2) of
slider 26. In the portion opposite the V-shaped recess
36 of slider core 34, bracket 28 has a portion 42 of V-
shaped configuration; the inner faces of portion 42,
facing slider 26, extend perpendicularly to each other
and are oriented at an angle of 45 to the direction 40
of displacement of slider 26. The four faces of the
V-shaped recess 36 and of the V-shped portion 42 to-
gether form a quadrangular opening.
In the V-shaped recess 86 of slider core 34, there are
arranged two press dies 44, and two further press dies
46 are arranged in the V-shaped portion 42 of bracket
28. All of the press dies 44,46 are congruent and have
their mutually opposed inner faces provided with con-
cave peripheral or pressing faces 48 extending over
90. The exact configuration of the pressing faces 48
by which the press dies 44,46 abut on a pressing member
49 to be pressed (see Fig. 2), will be described later.
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Each of the press dies 44,46 is provided, on its side
opposite from the pressing face 48, with an integrally
formed projection 50 which is received in a recess 52.
The receiving recesses 52 are formed on the confronting
fac~s of the the V-shaped recess 36 and the V-shaped
portion 42. The receiving recess 52 is larger, i.e.
longer than the width of the projection 50 so that the
press die is displaceably guided on the respective face
of the V-shaped recess 36 or the V-shaped portion
42. Due to this displaceability, the two press dies 44
of the V-shaped recess 36 can be moved towards each
other and away from each other in the same manner as
the two press dies 46 of the V-shaped portion 42. Fig.
2 shows the case in which the press dies 44 and 46 have
been moved away from each other while Fig. 3 shows the
case in which the press dies have been moved towards
each other and brought into mutual abutment. The moving
path of a press die in outward direction, i.e. from the
press die arranged in the same recess or the same por-
tion of slider core 34 or bracket 42, is limited by the
abutting of the outer end face of projection 50 against
the face of the appertaining receiving recess 52 op-
posite this end face, and the movement of the press
dies towards one another is limited by the abutment of
the two press dies and the abutting action of the other
end face of projection 50 against the face of receiving
recess 52 opposite thereto (for the last case, cf. Fig.
3).
In their starting positions, i.e. in their positions
maintained before the pressing process, the two press
dies 44 and the two press dies 46 are respectively
spaced from one another in circumferential direction.
Since the slider 26 at its rear end opposite the front
end is supported through pressure springs 54 against
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the base portion 58 of fork 24 connecting the fork arms
56, the slider 26 is biased in the direction of the
press dies 46 of bracket 28. Without the inserted
pressing member 49, the press dies 44 and 46 following
each other in circumferential direction, would lateral-
ly abut each other; with the pressing member 49 insert-
ed, however, the distance between the press dies 44 and
46 is substantially equal to the mutual distance of the
press die 44 or 46 from each other. This is also the
result of the configuration of the pressing faces 48 of
press dies 44,46. Also when the pressing member has not
been pressed yet, these pressing faces 48 lie against
the circumference thereof, notably to the largest poss-
ible extent in face-to-face abutment, which, however,
cannot be fully realized due to the different radii of
curvature of the pressing face and the circumferential
surface of the pressing member.
With reference to Figs. 6 to 9, a more detailed de-
scription will be given hereunder of the manner in
which the press dies 44,46 are received in the receiv-
ing recesses 52 and of the arrangement of the pressing
faces 48. This description will be rendered by way of
example with reference to press die 44 which is ar-
ranged in the upper half of the V-shaped portion 42 of
bracket 28 with respect to the side views of the tool
10 according to Figs. 1 to 4 and 10. Each of the press
dies 44 is biased into its starting position by means
of a helical pressure spring 60. The pressure spring
60 is received in a blind-end bore 62 formed in the one
end side of the press die projection 50 and extending
in the direction of the displacement of the press die.
The pressure spring 60 projects beyond the inner end
face of the projection, i.e the face directed to the
gorge of the V-shaped recess or the V-shaped portion
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and is supported on the face of the receiving recess 52
opposite thereto (see Fig. 7). Further, the projection
is provided with a spring-based locking ball 64
which is immersed in a locking recess 66 being in turn
formed in the face of the receiving recess opposite the
locking ball 64. The locking recess 66 is formed in
such a manner that the locking ball 64 will move there-
in when the press die 44 is being displaced. Thus, the
locking ball and the locking recess also act as a guid-
ance for guiding the press die 44 in the receiving re-
cess 52.
As is shown particularly in Figs. 6 and 9, the pressing
face 48 of a press die consists of three linear faces
extending in parallel to each other, being arranged at
distances from each other and being formed by the sur-
face of rib-like raised portions 68. The ends of the
rib-like raised portions 68 of two adjacent press dies
are distanced from each other although these abut each
other. The distance is relatively small and amounts to
a few millimeters only.
As can be seen especially in Fig. 3, the slider 26 is
guided on guide pins 70 inserted in through-holes of
the fork arms 56 and projecting beyond the mutually
facing inner faces 72 of the fork arms 56. The pro-
jecting portions of these confronting guide pins 70 are
immersed in lateral guide reccesses 74 machined into
the lateral edges of slider core 34. The guide pins 70
limit the advance movement of slider 26 by abutment on
the end face of guide recess 74 arranged to the rear
when viewed in advance direction (see particularly Fig.
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The receiving recesses 52 and the guide recesses 74 of
slider 26 can be formed in slider core 34 as in the
embodiment shown in the Figures. Alternatively, it can
be provided that these recesses are not only formed or
defined by the slider core but also by slider plates 32
connected to the slider core by knurled screws 76. This
would particularly offer the advantage of a simpler
manufacture of the locking recesses 66 in the press die
receiving recesses 52. On the other hand, there exist
diverse manufacturing techniques (e.g. material pro-
cessing by spark or arc erosion) which allow the for-
mation of the locking recesses 66 in the side faces of
the receiving recesses 52.
As is evident from the Figures, the two fork arms 56
have different lengths. On the end of the longer of the
two fork arms 56, the one end of bracket 28 is pivotab-
ly supported; bracket 28 is biased in the opening di-
rection by a leg spring 80 enclosing the pivot axis 78
between fork 24 and bracket 28. By means of another leg
spring 82, the locking arm 30 is biased against the
free end of bracket 28 or in lateral direction towards
slider 26. The free end of bracket 28 is provided with
a locking projection 84 immersed into a locking recess
86 of locking arm 30 when bracket 28 is locked. The
locking arm 30 is supported on the shorter one of the
two fork arms 56 so that the bracket 28 in the region
of its free end provided with the locking projection
84, is arranged substantially in parallel to the longer
one of the two fork arms and constitutes, as it were,
an extension of the shorter fork arm 56. In this end
portion 88, the bracket 28 extends laterally to slider
26. For preventing undesired twisting of bracket 28,
bracket 28 has its end portion 88 partially enclosed
between slider plates 32 which are provided with two
lateral projections 90 to this purpose (see Fig. 4).
- 21 - 2~
By the shortening of the fork arm 56 provided with the
locking bracket, the locking point between the bracket
and the fork arm is displaced towards the fork basis
58. This offers the advantage that the locking - as
seen from the viewpoint the assembly worker handling
the pressing tool - takes place before the pipe con-
duit connection. In addition to the simplified hand-
ling, this solution also complies with narrow space
conditions, notably if - as is usual with an under-
floor heating - the pipes or pipe conduits to be con-
nected are arranged side by side next to each other and
at a small distance to the wall arranged therebehind.
The narrow bracket 28 together with the displacement of
the locking or release mechanism to the assembly worker
makes it possible to use the pressing tool shown in the
Figures also in a restricted space.
The operàtion and the application of the pressing tool
10 will be described in short hereunder. For insertion
of the pressing member indicated by 49 in Fig. 2 into
the mouth of pressing tool 10 formed by the four press
dies 44,46, the bracket 28 of pressing tool 10 is
opened by actuating the locking arm 30 and is pivoted
to the side. Then, the bracket 28 is moved into the
closed position. During the closing movement, the press
dies 46 of bracket 28 will press - through pressing
member 49 - against the press dies 44 of slider 26
which thereupon will move back by a certain distance
against the force of the pressure springs 54. The
reason for this process is that the press dies 44,46 in
their starting position shown in Fig. 2 have a circum-
ferential distance from each other, with their pressing
~` faces 48 already abutting the circumferential surface
of the pressing member 49. The distance between the
press dies 44,46 and among themselves is shown in rela-
:
--
21~ .3
- 22 -
tively large dimensions in Fig. 2; actually, it can be
selected to be much smaller, which will depend also on
the type of pressing (hollow or round profile, cable
shoe or connector pressing or pipe conduit pressing).
After the bracket 28 has been moved into the closing
position, the hand-operated hydraulic device 12 is
actuated for moving the plunger 20 against the rear end
of slider 26 so that slider 26 will be moved in forward
direction upon further operation of the hand-operated
hydraulic device 12. Through the pressing faces 48, the
pressing member 49 is subjected to a pressing force for
effecting the pressing. During the advance movememt of
slider 26 in the actual pressing process, the press
dies 44,46 are displaced along the respective abutment
faces of the V-shaped recess 36 in slider 26 and of the
V-shaped portion 42 of bracket 28. By the displaceable
accommodation of the press dies 44 and the press dies
46, these will move towards one another; the advance
movement of slider 26 in the direction of the statio-
nary bracket 28 reduces the distance of two circum-
ferentially successive press dies 44,46. In this man-
ner, the linear movement of slider 26 is transformed
into a radial movement of press dies 44,-46 which, be-
cause the pressing faces 48 are arranged as surfaces of
the raised portions 68 forming a circle, leads to con-
centric constrictions of the pressing member 49. A pipe
connection which can be formed through pressing action
by use of the pressing tool provided with such pressing
faces, is described in the German Utility Model speci-
fication DE 90 60 310.9 U1 of the applicant. The dis-
closure of this German Utility Model specification is
herewith incorporated by reference into the disclosure
of the instant invention.
.
~ ,, . ., . - .
2~? f'~
- 23 -
In connection with the different embodiments of a pipe
conduit fitting shown in Figs. 11 and 12, there will be
described now the manner in which the pressing tool 10
during the pressing process is fixed on the fitting
while being secured against axial displacement. The
pipe conduit connectors of Figs. 11 and 12 to be used
for interconnected pipes comprise a clutch-like support
body 92 which in its middle is provided with a circum-
ferential collar or circumferential shoulder 94. Onto
the support bodies 92, the ends of two pipes 96 are
mounted on both sides. Around the pipe ends, there are
arranged elastically deformable pressing members 49
formed as pressing shells. The pressing shells, being
deformed during the pressing process, become anchored
to the material of the pipes whose material in turn
penetrates into circumferential recesses of support
body 92, thus safeguarding a positive and a non-posi-
tive connection between the pipe and the connector.
The sectional views shown in Figs. 11 and 12 substan-
tially correspond to the sectional view shown in Fig. 6
except for the difference that also the pipe is shown
together with the fitting to be pressed.
-
For axially fixing the presing tool 10 to the fittingor pipe connection piece, the ends of the slider plates
fAcing towards bracket 28 have edge recesses 28 formed
therein which surround the pipe, the pressing shell and
the circumferential shoulder. The recesses 98 of the
two slider plates 32 are flush with each other and with
the opening limited by the pressing faces 48 of the
press dies 44,46. The slider plates 32 are extended
beyond the two slider press dies 44 and thus enclose
these press dies 44 to both sides. According to Fig.
11, the edge of the slider pl~te rece~s ga is i=ersed
,
'
:
-- 24 -- 2~ ?73
into a circumferential groove 99 formed in the circum-
ferential shoulder 94. Thereby, the whole tool is se-
cured against axial displacement. In this position of
the pressing tool 10 and the fitting relative to each
other, the second slider plate 32, on the frontal end
of the pressing shell facing away from the circum-
ferential shoulder 94, abuts the annular surface of
this end, with the appertaining edge recess 98 other-
wise surrounding the pipe 96.
For pressing the fitting onto a support body 92 accord-
ing to Fig. 12, in a case when the circumferential
shoulder is not provided with a circumferential groove,
there is used a slider plate 32' which is formed like a
fork at its end facing toward bracket 28. The C-shaped
edge 32 of slider plate 32 delimiting the recess 98
grips around the circumferential shoulder 94 from both
sides; the other slider plate 32 can abut the frontal
end of the pressing shell facing away from circumferen-
tial shoulder 94, as has been the case with the fitting
of Fig. 11.
