This invention relates to a device for driving and guiding a rapier
of a weaving machine, comprising a rotatable drive wheel provided for driving a
rapier rod in a back and forth movement, and a guide channel formed by adjustable
guide bodies in order to guide the said rapier rod according to a guide path in
co-operation with the drive wheel. This invention further relates to a rapier weaving
machine provided with at least one such drive and guide device.
A rapier weaving machine is equipped with one or more rapier systems,
each rapier system comprising two co-operating rapiers. Each rapier system is provided
for inserting a weft yarn into a shed formed between the warp yarns each time in
successive inserting cycles. In each inserting cycle, the rapiers situated on
either side of the shed are first moved towards one another in this shed, while
the one rapier takes along a weft yarn. The rapiers meet in the middle of the
shed and there the weft yarn taken along is taken over by another rapier. Finally,
both rapiers are withdrawn from the shed back into their original positions.
For a good operation of such a rapier system, the two co-operating
rapiers have to meet in a respective position (hereafter called "the take-over
position"), making an impeccable take-over of the weft yarn possible. Furthermore,
the movement path of the rapiers must be situated at the right height, almost
in the plane of symmetry of the shed. With narrow weaving machines, the movement
path of the rapiers must run parallel to the reed. With wide weaving machines,
the rapier heads must lean against the reed in order to obtain a safe take-over
of the weft yarn. For these reasons the known drive and guide devices for rapiers
are provided with means, with which the movement paths of the rapier can be exactly
Known rapiers primarily consist of a rapier rod with a built-in gear-rack,
which carries a rapier head at its extremity that is provided with gripping means
to take along a weft yarn. The rapier drive occurs by means of a drive gearwheel
that acts on a gear-rack and is rotated in the one and the other sense of rotation
alternatively in order to move the rapier into or out of the shed. In order to
keep the rapier rod within reach of the drive gearwheel during this drive and
to avoid lateral movements of the rapier rod, this rapier rod is guided in a U-shaped
In the Belgian patent n° 1 000 994 a drive and guide device for such
a rapier is described, having a moulded guide channel for the rapier rod, in which
a series of guide rollers is provided opposite the drive gearwheel. The guide
channel is connected, in a manner adjustable as to height, to the casing of the
drive gearwheel, and this casing itself is likewise rotatable in order to be able
to give the guide channel the exact orientation. These adjustments allow the take-over
position of the rapier head to be adjusted in order to obtain an efficient take-over
of the weft yarn. The guide rollers are mounted in a frame that is adjustable in
a direction at right angles at the paths of movement in order to guide the rapier
rods at the exact distance of the drive gearwheel. This device has the disadvantage
that particularly much heat is developed, and that the rapier rods, especially
at relatively high weaving speeds, are subject to premature wear.
In the Belgian patent n° 1 004 622 such a drive and guide device
is described, the U-shaped guide channel of which is formed between a profile with
an L-shaped cross-section on the one side, and a guide ruler, hingedly attached
and which can be moved back in order to open the guide channel at the front, on
the other side. The guide ruler comprises only one guide roller near the point
where the drive gearwheel acts on the gear-rack to absorb the radial force exerted
by the gearwheel on the rapier rod. The guide ruler with the guide roller is adjustable
in a horizontal direction at right angles on the direction of the path of movement.
The L-section is supported by a carrier arm, which is adjustable in a horizontal
In order to limit wear and development of heat to a minimum, it is
important that the gear-rack is guided at the correct distance from the gearwheel.
On the other hand, the rapier rod also is to be guided at the correct height, so
that the gearwheel might act in the middle of the tooth space of the gear-rack.
This to avoid that the teeth should rub against the sidewalls of the tooth spaces
of the gear-rack. If both clearances (the horizontal and the vertical clearances)
are not adjusted correctly, this might provoke premature wear of the gear-rack
and an exaggerated heating of the rapier envelope, which will cause its rapid decline.
To adjust the horizontal clearance of the device according to the
Belgian patent n° 1 004 622 first the carrier arm to which the L-section is attached
must be moved in the horizontal direction, and thereafter the hinged guide ruler
with the guide roller must be adjusted again into the correct position in order
to obtain a guide channel having the exact width. In order to be able to adjust
the vertical clearance the L-sections can be adjusted as to height, but the hinged
guide ruler must be adjusted separately on the side of the guide roller by inserting
or removing thin shims between the hinge and the guide slat. The installation level
of the drive gearwheels can also be adjusted step by step by means of shims. These
adjustments of the vertical and horizontal clearances are difficult to perform
and cannot be carried out with the required precision and moreover, they are particularly
time-consuming and complicated.
The purpose of the present invention is to provide for a drive and
guide device for a weaving machine rapier, allowing an easier and more precise
adjustment of the clearances between gearwheel and gear-rack, and the working
of which, because of an improved adjustment of these clearances, will cause less
wear and development of heat.
The purpose mentioned above is attained by a drive and guide device
for a rapier of a weaving machine, comprising a rotatable drive wheel, provided
in order to give a back and forth movement to a rapier rod and a guide channel
formed by adjustable guide bodies in order to guide the said rapier rod along
a guide path in co-operation with the drive wheel, the guide bodies, according
to this invention, being a part of a guide unit, which, as a whole, is adjustable
in order to modify the distance between the guide path and the axis of rotation
of the drive wheel, and the drive wheel which is continuously adjustable along
the longitudinal direction of its axis.
With this device, the distance between the drive wheel and the rapier
rod can be adjusted in a direction at right angles to the plane of the axis by
simply sliding the guide unit. A continuous adjustment of the drive wheel in the
direction of the drive shaft makes it possible to mutually modify and adjust the
installation of drive wheel and rapier rod, also in the direction of the axis.
Both adjustments can be performed very easily and with great precision, so that
the said clearances may be adjusted with optimum precision in order to obtain
a drive and guide device reducing wear and development of heat to a minimum.
Preferably, the drive wheel is attached to its shaft in a continuously
adjustable manner by means of an internal bicone shaft hub connection.
In a preferred embodiment, the device according to this invention is carried out
in such a manner that the said guide unit is slidable over a supporting surface
in order to adjust the said distance. Because of this construction of the guide
unit, there is no need for a supplementary support after the fastening or fixing
means have been loosened and adjustment may occur in a particularly precise manner,
for instance, by means of an adjusting spindle screw.
Preferably, the drive wheel is provided on the shaft in a slidable
manner, while an internal bicone shaft hub connection for fixing it in the desired
position is provided.
Preferably the device is carried out with a guide unit comprising
also guide means to absorb the forces exerted by the drive wheel on the rapier
rod in the guide channel. Because the guide means are part of the adjustable guide
unit, the position of the guide means, with respect to the guide path, is maintained
when adjusting the guide unit.
Preferably, the said guide means comprise a rectilinear air bearing.
Such an air bearing is capable of absorbing strong radial forces, so that development
of heat is considerably reduced in consequence of which the life of the rapier
rods and of the guide bodies is considerably increased. Moreover, the development
of heat in the air bearing can be monitored by means of a temperature sensor, so
that the weaving machine can be put out of action in case of too sharp a rise
in temperature. This may happen, for instance, in consequence of a breakdown of
the compressed air supply or of the air inlet holes of the bearing getting clogged.
In this way, damage to the rapier rods can be avoided.
Preferably, the said guide means, and particularly the air bearing
mentioned above, are installed in such a manner that they determine a guide surface
situated in the same plane as a guide surface of the guide channel. Because of
this, the rapier rod remains straight under the highest radial or lateral loads.
In a particularly preferred embodiment, the device is provided with
a guide unit comprising a guide slat, which can be brought into an operative position
in which the guide channel is limited on one side and is movable into another
position in order to make the guide channel accessible on the said side. In such
an embodiment, a rapier rod can be removed from the guide channel very easily.
Preferably, the guide slat is hingedly attached to a fixed part of
the guide unit. In addition to that, the guide channel may be constituted by the
said guide slat on the one side and an elongated moulded piece having an L-shaped
cross-section, while the guide slat is attached to the moulded piece in a hinged
In an advantageous embodiment, the said guide means, and more particularly
the air bearing, are attached to the guide slat, while the guide slat is adjustable
in order to modify the width of the guide channel. Because the guide slat and
the guide means are adjustable together, now the adjustment of the width of the
guide channel can be carried out very easily and rapidly. It may, for instance,
be necessary to adapt the width of the guide channel to a rapier rod having deviating
In a preferred drive and guide device, the guide unit is attached
to a casing or part of a casing for one or several drive wheels. Several guide
units can be adjustably attached to a respective segment of a casing and these
segments can be placed above one another in such a manner that they form the complete
casing for a number of drive wheels, provided above one another, while the guide
units are provided for guiding rapier rods, co-operating with these drive wheels.
When the word casing is used in this patent application, then both a complete
casing and a component part of a casing are meant.
Preferably, each guide unit is also rotatable as a whole in order
to adjust the direction of the guide path. This will permit an exact adjustment
of the guide path in order to obtain an ideal take-over position of the rapier
When the guide unit is attached to a casing for the drive wheel and
said casing is rotatable with respect to the axis of the drive wheel, the take-over
position of the rapier head can be adjusted, while the adjustments of the clearances
between the rapier rod and the drive wheel remain unchanged.
In a preferred embodiment, the casing for the drive wheel can be
fixed in an adjusted position by means of fixing means, in which case fixing and
loosening these fixing means may be carried out near a top of said casing. Because
the fixing means are well accessible, adjusting the direction of the guide path
can be carried out easily and rapidly.
Preferably, the device comprises a casing for the drive wheel and
a bearing housing in which the bearings of the shaft of the drive wheel are lodged,
the guide unit being attached to the casing of the drive wheel and the casing for
the drive wheel being attached to a fixed part of the device, so that the bearing
housing is detachable while the settings of the guide unit are maintained. This
means a considerable time-saving in case of inspection or replacement of the bearing
or of any other piece of this part incorporated in the bearing housing, such as,
for instance, a bevel gear on the drive shaft.
In a most preferred embodiment the guide unit is attached to a casing
for the drive wheel by means of a fastening means with two legs, which legs are
adjustably attached to this casing, on both sides of the casing and resting on
supporting surfaces respectively, moulded on this casing, the distance between
the guide path and the axis of the drive wheel being adjustable, because said legs
may be shifted over their respective supporting surfaces and may be fixed in a
position as desired.
The device may also be carried out having at least two guide units
installed above one another, each guide unit being attached to a respective part
of a casing for one or several drive wheels, thus this device can be carried out
to drive and guide the rapiers of a double rapier weaving machine, or of a weaving
machine with three or more rapier systems working above one another. Moreover,
each guide unit can be installed individually without the adjustment of the one
guide unit being influenced by the other unit.
Moreover, each guide unit can also be adjustable as a whole, in a
direction running practically parallel to the axis of the drive wheel. This is
possible, for instance, by means of shims and may be necessary, among other things,
to adapt the differences in height between the guide units provided one above
the other to the desired pile height.
Preferably, the guide unit also comprises an extensible rod, which
carries a supporting means for a rapier head. When the height or the orientation
of the guide channel or its distance with respect to the drive shaft is modified,
the position of the supporting means is likewise adapted in a suitable manner.
A very suitable embodiment is carried out in such a manner that the
guide path is practically horizontal, that each guide unit is movable, as a whole,
in a horizontal plane in order to adjust the distance between the guide path and
the axis of the drive wheel, is rotatable in a horizontal plane in order to adjust
the direction of the guide path and is adjustable as to height in order to adjust
the height of the guide path.
This invention further relates also to a rapier weaving machine comprising
at least one rapier moving back and forth having a drive and guide device carried
out in accordance with this invention.
These and other characteristics and particulars of the device according
to the present invention will be clarified and illustrated in the following detailed
description of one of its possible embodiments.
It may be clear that the only purpose of this description is to clarify
the invention by means of an example and therefore in no way may be considered
as a limitation of the scope of this patent protection.
In this description reference is made, by means of reference numbers,
to the attached drawings of which:
- figures 1 and 2 are perspective representations of a device for driving and
guiding a rapier according to the present invention;
- figure 3 is a vertical cross-section of the device represented in the figures
1 and 2, according to the axis A-A indicated in these figures;
- figure 4 is a top view at the level of the drive wheel of the device represented
in the figures 1 and 2;
- figure 5 represents two such drive and guide devices, provided above one another
for driving and guiding rapiers working one above the other of a double rapier
- figure 6 is a vertical cross-section according to the plane of the drive shaft
of the two devices represented in figure 5;
- figure 7 is a vertical cross-section of a part of the device represented in
figure 5 according to the axis B-B indicated in this figure;
The drive and guide device represented in the figures 1 and 2 comprises
a drive wheel (1) mounted on a drive shaft (2) extending vertically and incorporated
in a casing (3), hereafter called "the drive casing (3)". The drive casing (3)
has laterally projecting collars (4),(5) on two opposite flanks, the tops of which
constitute a horizontal supporting surface (6),(7) for the legs (15),(16) of the
fastening fork to be further described. Under the drive casing (3) a second housing
(8) has been provided, (hereafter called "the bearing housing (8)" in which the
bearings of the drive shaft have been incorporated.
A guide unit (9) is attached to the drive casing (3). It consists
of an elongated moulded supporting part (10) having an L-shaped cross-section (hereafter
called "the L-section (10)", a guide ruler (11) with built-in air bearing (12)
hingedly connected to this L-section (10) and an extensible rod (13), forming
a whole together. Between the L-section (10) and the guide ruler (11) a U-shaped
guide channel for a rapier rod is formed. A cross-section of the channel for such
a rapier rod (14) is only represented in figure 3. The rod (13) is slidable in
a separate channel (29) and carries a support (30) at its extremity to support
a rapier head and to guide the rapier rod.
The guide unit (9) is attached to the drive casing (3) in such a
manner that the distance between the centre line of the drive shaft (2) and the
U-shaped guide channel is adjustable. To that effect, the L-shaped section (10)
is provided with an fastening fork having two parallel legs (15),(16) extending
at right angles to the longitudinal direction of the L-section on both sides of
the drive casing (3) and are resting on the horizontal supporting surfaces (6),(7)
of the collars (4),(5) mentioned above. In order to adjust the distance between
the centre line of the drive shaft (2) and the guide channel, the legs (15),(16)
may be slid over the said supporting surfaces (6),(7).
The L-shaped section (10) extends over the full length of the rapier
rod when this rod has been withdrawn completely from the shed. The L-section (10)
is preferably made of one piece, has an L-shaped section at one side and the opposite
side is provided with the fastening fork mentioned above having two cross-directed
legs (15),(16). These legs are made integral with the L-section. Shifting of the
said legs (15),(16) over their respective supporting surfaces (6),(7) is done
by an adjusting spindle screw (17) acting on one of the legs (15),(16). Finally,
to fix the fastening fork, use is made of a bolt connection (18). Shifting occurs
in the warp direction. During this shifting, the guide unit (9) is maintained
in a horizontal position, because the legs (15),(16) are resting on the said horizontal
supporting surfaces (6) , (7) of the collars (4) , (5) forming integral parts
of the drive casing (3). In this manner, adjusting can be performed with great
In order to absorb the radial forces exerted on the rapier rod (14)
by the drive gearwheel (1) and to prevent the development of heat, a rectilinear
fixed air bearing (12) of sufficient length is built into the extendible guide
ruler (11) in the place of the zone of action between the drive gearwheel (1)
and the gear-rack of the rapier rod. This bearing (12) is capable of absorbing
strong radial forces developing much less heat. Because of which the life of the
rapier rod is considerably prolonged.
The guide surface of the air bearing (12), i.e. the surface in which
the holes of the air blowers are situated and the guide surface of the hinged guide
ruler (11) are situated in a same plane, so that the rapier rod in rest as well
as in motion has a perfectly smooth guide surface. Because of this, the rapier
rod is maintained in a perfectly upright position, even when under the influence
of the heaviest radial and lateral loads in consequence of the action of the drive
gearwheel (1). The rapier rods (14) are guided better and the take-over is strongly
improved at high weaving speeds. This is confirmed by a reduced number of stops
of the weaving machine due to loss of weft yarn at or after the central take-over
of the weft yarn.
The development of heat in the air bearing (12) is monitored by a
temperature sensor (not represented in the drawings). In case the temperature should
become too high because of a breakdown of the compressed air supply or of the air
blowing holes being obstructed, the weaving machine is put out of action for an
inspection, because of which any damage to the rapier rods is avoided.
The rapier drive gearwheel (1) is continuously adjustable as to height
by shifting it on its drive shaft (2) and this adjusting height is adapted to the
height of the rapier rod lying on the L-section (10), consequently the action takes
place in the middle of the gear-rack. The rapier drive gearwheel is fixed in the
desired position by means of an internal bicone shaft hub connection (19).
Furthermore, the drive casing (3) can be rotated with respect to the drive shaft
(2) and be adjusted in an orientation as desired. At the bottom the drive casing
(3) is centred around a collar (20) of the bearing housing (8) and is fixed by
two vertical bolts (21), (22), the heads of which reach up to the top surface of
the drive casing (3). At the top, these bolts (21),(22) are easily accessible.
In order to adjust the direction of the rapiers in a precise manner, a second
adjustable fixing point (23) to attach the L-section (10) to the frame of the weaving
machine is provided on the other side, away from the rapier drive casing. Here
also an adjusting spindle screw has been provided for adjusting purposes.
In order to be able to free the drive shaft (2) without removing
the guide unit (9) the drive casing (3) is centred on the collar (20) of the bearing
housing (8) but this is realized in such a manner that the bearing housing (8)
can be removed without being obliged to remove the guide unit (9). The drive casing
(3) remains firmly fixed to the frame of the device by means of the bolts (21),(22).
During this operation, the settings of the guide unit (9) can be maintained completely.
This means a considerable saving of time during inspections or when replacing the
bearings of the bevel gear on the drive shaft (2).
The guide ruler (11) is hingedly attached to the L-section (10).
The guide ruler (11) is attached to the hinges by means of bolts (25) in order
to be able to adjust the clearance of the rapier rod in the U-shaped guide channel
and therefore to be able to adapt the width of the channel to the varying dimensions
of the cross-sections of the rapier rods sections. Because the guide ruler (11)
and the air bearing (12) are in one piece, this adaptation can be performed easily
The height of the U-shaped guide channel is adjustable in a step
by step manner by means of shims (25),(26), which can be placed or not on the supporting
surfaces (6),(7) of the drive casing (3) and under the protruding legs (15, 16)
of the guide unit (9) (as represented in figure 6). The exact distance of the
drive gearwheel (1) is adjusted continuously with respect to the centre of the
gear-rack of the rapier rod by moving the drive gearwheel (1) on its shaft (2),
the gearwheel (1) being fixed in the desired position by means of an internal
bicone shaft hub connection (19).
The building up of a drive and guide device for a double rapier weaving
machine or for a weaving machine having three or more rapiers (see figure 5, 6
and 7) is done by positioning drive casing segments (27),(28) in layers above
one another, to which each time a guide unit (9) of the above-mentioned construction
is attached. Each drive and guide device should be installed at the level at which
a shed is formed. When weaving face-to-face pile fabrics the difference in height
between the sheds formed above one another depends on the pile height to be woven.
This adjustment in height is done in continuously by putting one or several shims
(26),(26') having a certain thickness between the respective drive casing segments
(27). Adjusting the direction or orientation of the rapier rods (14) - in a horizontal
plane - is done with the help of bolts (21),(22), passing all through these drive
casing segments (27),(28), and the heads of which are well accessible at the top
for loosening and fastening the connection. The drive casing segments (27),(28)
are centred in the drive casing (3) or with respect to each other by means of a
projecting collar. These segments (27),(28) each have their own collar (4),(5),
forming supporting surfaces (6),(7) for the legs (15),(16) of an L-section (10)
and an adjusting screw spindle (17) for adjusting the distance between the shaft
of the gearwheel (2) and the guide channel. In this manner, each guide channel
can be adjusted separately.
The two drive gearwheels (2) provided above one another are continuously
adjusted as to height on a common drive shaft (2) in order to adapt their in-between
distance. This is done by an adjustable displacement on the vertical drive shaft
(2). The drive gearwheels (2) can be placed perfectly in the centre of the gear-rack
of the rapier rod and be fixed on the common shaft (2) by means of a screw via
an internally placed bicone shaft hub connection (19).
Each drive casing (3) or each drive casing segment (27),(28) is provided
with a channel (29), either at the top or at the bottom, in which an extensible
rod may be attached. At its free extremity, the rod (13) carries a support or guide
table (30) for the rapier heads. By moving these rods (13) in or out, these supports
(30) are placed exactly where they are needed in accordance with the width of the
fabric to be woven. Each rod (13) is attached to a respective guide unit (9),
so that a modification of the distance between guide channel and drive shaft (2)
or of the direction of the movement path of the rapier on a certain guide unit
will immediately result in a corresponding adjustment of the supports (30) of
the rapier heads concerned.
On the drive and guide device according to the invention therefore,
each guide unit can be adjusted individually without adjusting the one having any
influence on another guide unit. Adjustments can be made with great precision and
are far less time-consuming. Moreover, the rapier bearing will develop far less
heat, even at higher weaving speeds. By means of a temperature sensor the device
can be monitored very easily.