BACKGROUND OF THE INVENTION
[0001] The present invention relates to a mechanical assembly, effective to reciprocately
driving the pliers bearing tape in a textile loom.
[0002] As it is known,presently in many looms the weft threads are inserted into the warp
threads by means of pliers pairs,as suitably designed ana driven with a reciprocating
movement,in opposite directions.
[0003] Said pliers as mounted at one ena of corresponding tapes,as provided with a plurality
or cross slots, in such a way as to be able of engaging with spur gears.
[0004] These latter are reciprocated by means or driving mechanisms which are usually very
complicated,because of the great amplitude of rotation to be transmitted to said spur
gears.
[0005] Practically the thereinabove cited driving mechanisms generally comprise large diameter
pulleys, cooperating with connecting rods and oranks effective to transform the movement
and, accordingly, the have a great inertial mass.
[0006] This fact acts against obtaining a suitable
[0007] evenness in the variations and reversions of the movements of the weft thread inserting
pliers.
SUMMARY OF THE INVENTION
[0008] Accordingly the task of the present invention is to eliminate the thereinabove cited
drawback,by providing a mechanical assembly, effective to reciprocately driving the
pliers bearing tapes in textile looms,having drastically reduced inertial masses.
[0009] Within said task,it is a main object of the present invention to provide such a mechanical
assembly,effective to reciprocately driving the pliers bearing tapes in textile looms,which
comprises a reduced number of component parts,effective to mutually cooperate,in such
a way as to provide a greatly efficient and sure operating assembly.
[0010] The task and object thereinabove mentioned,as well as yet other objects which will
become more apparent thereinafter are achieved by a mechanical assembly effective
to recirpcately driving the pliers bearing tapes in textile looms,characterized in
that it comprises a toothed pulley,eccentrically thereto there is pivoted a spur gear,supporting
an arm member at one end thereof there is articulated a slider rigid with a toothed
belt,said spur gear meshing with an internal gear,said toothed belt engaging with
a second spur gear,meshing with said pliers bearing tape, said toothed pulley being
driven,through a belt or the like driving member, by a driving pulley and eccentrically
supporting the axis of said first spur gear meshing with said internal gear as mounted
cantilever-wise on said loom shoulder.
[0011] Advantageously said driving pulley is mounted at one end of a high speed operating
shaft,bearing a brake assembly at both ends thereof and effective to transmit movement
to the two ends of the swingable shaft.
[0012] Owing to this approach the possibility is eliminated of possible torsion phenomena
on said swingable shaft during the braking, which would occur in looms provided with
a brake assembly at the motor or at one end only or the shaft.
[0013] Said first spur gear supports an arm member or crank, on the pin thereof there is
pivoted a slider, formed by two adjoining plates and effective to clamp a portion
of an endless toothed belt which, through transmission members and a tension member,
engages the shaft or the second spur gear, this latter meshing with said pliers bearing
tape.
[0014] In particular, said slider and crank may be joined to one another by means of interposed
connecting Furthermore,in order to restrain the tapes from vibrating, which would
damage the warp threads, and to control the shed opening, there is provided a device
which restrains the tape only at the edge opposite to the comb, thereby said tape
is able of sliding in a position nearly adhering to said comb.
[0015] Said tape guiding device consists of a L-shaped section,made rigid with the loom
slay and bearing, at the free end of its horizontal wing,a plurality of vertically
extending shaped plates,as evenly spaced, and provided,at the top thereof, with a
parallel wall recess:at the top of the vertical wing of said section there is fixed
a resilient material rectangular cross-section rod,provided with a suitably stiffened
and abrasion resistant surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Further characteristics and advantages of the mechanical assembly effective to reciprocately
driving the pliers bearing tapes in textile looms,according to the present invention,
will become more apparent from the figures of the accompanying drawings,relating to
a preferred and essentially indicative embodiment of the invention and where:
fig.l is a schematic side view illustrating the mechanical assembly according to the
present invention;
fig.2 is a perspective view illustrating that same mechanical assembly;
fig.3 is a detail view illustrating the fixed spur gear and the planetary gear as
eccentrically mounted to the driven pulley;
fig.4 illustrates the spur gear effective to transmit the reciprocating movement to
the pliers bearing tape;
fig.5 is a plan view illustratting the arrangement of the mechanical assembly on the
two shoulders of a textile loom provided with a high speed operating shaft; and
fig.6 is a cross-section view illustrating the tape guiding device.
DESCRITPION OF THE PREFERRED EMBODIMENT
[0017] With reference to the number references of the figures of the accompanying drawings,
the mechanical assembly according to the present invention comprises a toothed pulley
1 driven, through a belt 2 or other suitable driving member,by a driving pulley 3.
[0018] This toothed driving pulley eccentrically supports the axis 4 of a spur gear 5,meshing
with the teeth of an internal gear 6,as fixed, cantilever-wise,on the shoulder 7 of
the loom.
[0019] Said spur gear, in turn, supports a crank 8 to the pin thereof there is pivoted a
slider 9, formed by two adjoining plates.
[0020] The slider 9 is effective to clamp a portion of a toothed belt 10 which, througn
transmission members 11 and a tension member 12,engages the shaft 13 of a further
spur gear 14.
[0021] Practically, by rotating the pulley 1, the axis of the spur gear 5 moves on a circular
path,in such a way that said spur gear is able of meshing with the teeth of said fixed
internal gear 6.
[0022] Accordingly, this latter is driven with a planetary movement, in such a way as to
cause the pin of the crank 8 to rectilinearly reciprocate.
[0023] The slider 9, therefore, drives, with a like reciprocating movement, the toothed
belt 10, there by causing the spur gear 14 to rotatively reciprocate.
[0024] This latter engages the pliers bearing tape 15,restrained in the guide 16, thereby
causing said tape to reciprocate.
[0025] It is moreover provided the possibility of replacing the direct fixing of the slider
y by connecting rods, in such a way as to vary the stroke of said pliers bearing tape.
[0026] Advantageously, said driving pulley 3 is mounted at one end of a high speed operating
shaft 17, bearing at both ends thereof a braking assembly 18, effective to transmit
movement to the two ends of the swingable shaft 19.
[0027] Moreover,it is possible to provide for the use of a tape guiding device 20,formed
by a L-shaped section member 21 made rigid with the loom slay 22.
[0028] The vertical wing 21' of said section member is located at one side of the loom comb
23 and supports, at the top thereof,an elastomaeric or plastics material rod 24,provided
with a suitably stiffened and abrasion resistant surface.
[0029] On the free edge of that same section member there are fixed a plurality of shaped
plates 25 as evenly spaced at adjoining positions,
[0030] These plates are provided with a top recess 26 in such a way as to jointly provide
a sliding guide effective to restrain an edge of the tapes 27 bearing the pliers 28.
[0031] It should be noted that the aforesaid resilient material rod 24 is located at a slightly
lower level than the theretical sliding plane of said tapes,in order not to hinder
the passage of the warp threads 29, not rised by the heddles.
[0032] That same rod,anyhow,advantageously acts as a damping member, against possible vibrations
of said pliers bearing tapes.
[0033] From the above description and the observation of the figures of the accompanying
drawings the great functionality and use facility characterizing the mechanical assembly
effective to reciprocately driving the pliers bearing tapes in textile looms according
to the present invention are self-evident.
[0034] Obviously the mechanical assembly has been illustrated and described only by way
of an indicative and not limitative example,and only to demonstrate the practicing
and main characteristics of the present invention and,accordingly,it should be pointed
out that it is susceptible to all of variations and modifications as falling within
the scope of the invention.
1- A mechanical assembly effective to reciprocately driving the pliers bearing tapes
in textile looms, characterized in that it comprises a toothed pulley, eccentrically
thereto there is pivoted a spur gear, supporting an arm member at one end thereor
there is articulated a slider rigid with a toothed belt, said spur gear meshing with
an internal gear, said toothed belt engaging with a second spur gear, meshing with
said pliers bearing tape, said toothed pulley being driven, through a belt or the
like driving members by a driving pulley and eccentrically supporting the axis of
said first spur gear meshing with said internal gear as mounted cantilever-wise on
said loom shoulder.
2- A mechanical assembly,according to claim 1, characterized in that said driving
pulley is mounted at one end of a high speed operating shaft, said shaft supporting
a braking member at both ends and being effective to transmit movement to both ends
or a swingable shaft.
3- A mechanical assembly, according to one or more of the preceding claims, characterized
in that said first spur gear supports an arm member or crank, on the pin thereor there
is pivoted said slider, formed by to adjoining plates and effective to clamp a portion
of an endleas toothed belt which, through transmission members and a tension member
engages the shaft or said second spur gear meshing with said pliers bearing tape.
4- A mechanical assembly, according to one or more of the preceding claims, characterized
in that said slider and crank are joined to one another by means or interposed rod
members.
5- A mechanical assembly, according to the preceding claims, characterized in that
it provides for the use of a tape guiding device, formed by a L-shaped section made
rigid with the loom slay and bearing, at the free end of its horizontal wing, a plurality
or evenly spaced vertically extending shaped plates provided, at the top thereof,
with a vertically extending wall recess,at the top of the vertical wing of said section
there being fixed a resilient material rectangular cross-section rod,as provided with
a stiffened and abrasion resistant surface.