Information
-
Patent Grant
-
6289755
-
Patent Number
6,289,755
-
Date Filed
Thursday, October 7, 199924 years ago
-
Date Issued
Tuesday, September 18, 200122 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Dann, Dorfman, Herrell and Skillman
- Skillman; Henry H.
-
CPC
-
US Classifications
Field of Search
US
- 074 110
- 139 455
- 139 59
- 139 329
- 139 88
- 139 85
- 139 86
-
International Classifications
- F16H2144
- F16H2154
- F16H2518
- D03C300
-
Abstract
A drive transmission assembly for transmitting motive drive between a reciprocating drive member (11) and a driven member (16) in order to move the driven member (16) between first and second limits of reciprocal movement, the assembly including a drive transmission member (20) adapted for connection to the drive member (11) and the driven member (16) in order to transmit said motive drive, a fixed stop member (22) arranged to be located within the path of reciprocal travel of said transmission member (20), the transmission member (20) including a stop (25) for abutment with said stop member (22) in order to define said first or second limit of reciprocal movement for the driven member (16), said transmisson member (20) being adapted to define a vibration isolating connection between said stop (25) and said drive member (11), whilst said stop (25) is in abutment with said stop member (22).
Description
The present invention relates to a drive transmission assembly for transmitting motive drive between a reciprocating drive member and a driven member.
In particular, the present invention relates to such a transmission assembly which is used to connect the output from a Jacquard mechanism to the heald(s).
It is a common condition in jacquards that the Jacquard output to the loom is subject to small oscillation either at bottom shed or top shed or both, in addition to the normal lifting and lowering of the outputs which takes place as ends are selected and deselected. Elimination of these oscillations within the Jacquard may be difficult or impossible without considerable changes to the mechanism or extensive fine adjustment of the machine. Components of vertical oscillation may also occur because of vibrations in the Jacquard mounting and the gantry. These secondary oscillations can however be very detrimental to the other components of the weaving system, such as the harness.
According to one aspect of the present invention there is provided a drive transmission assembly for transmitting motive drive between a reciprocating drive member and a driven member in order to move the driven member between first and second limits of reciprocal movement, the assembly including a drive transmission member adapted for connection to the drive member and the driven member in order to transmit said motive drive, a fixed stop member arranged to be located within the path of reciprocal travel of said transmission member, the transmission member including a stop for abutment with said stop member in order to define said first or second limit of reciprocal movement for the driven member, said transmission member being adapted to define a vibration isolating connection between said stop and said drive member whilst said stop is in abutment with said stop member.
Preferably dampening means are provided for dampening impact of the stop with said stop member.
Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which:
FIG. 1
is a diagrammatic view illustrating the principle of operation of a drive transmission assembly according to the present invention;
FIG. 2
is a schematic side view of a first embodiment according to the present invention;
FIG. 3
is a schematic side view of a second embodiment according to the present invention;
FIG. 4
is a schematic side view of a third embodiment according to the present invention; and
FIG. 5
is a schematic longitudinal section showing a modification to the drive transmission assembly according to the invention.
Referring initially to
FIG. 1
, there is shown a Jacquard mechanism
10
including an output member
11
which is moved, when selected, between upper shed US and lower shed LS positions. Jacquard mechanisms
10
of this type are well known, for example see GB 2047755.
The output member
11
is drivingly connected to a heald harness
15
via a transmission assembly
20
according to the present invention. The harness
15
in the illustration comprises three harness cords
16
. Each harness cord
16
passes through a comber board
17
and is connected to a spring
18
in a conventional manner. The springs
18
collectively apply a downward biasing force T
H
on the transmission assembly
20
. Each harness cord
16
carries a heald
19
in a conventional manner. The transmission assembly
20
includes a stop member
22
which is preferably rigid and fixedly supported so as to be isolated from vibrations in the Jacquard
10
. Preferably the stop member
22
is mounted upon the main frame
23
of the loom (not shown) with which the Jacquard machine co-operates.
The transmission assembly
20
flirter includes a stop
25
which is biased by springs
18
into abutment with the stop member
22
to define a lower shed position for the heralds
19
.
The stop
25
is raised out of abutment with the stop member
22
when the output member
11
moves to its upper shed position US in order to move the heralds
19
to their upper shed position.
When the output member
11
is located at its lower shed position vibrations within the Jacquard mechanism can cause the output member
11
to vibrate or oscillate over a distance V
0
. The transmission assembly
20
is constructed so as to define a vibration isolating connection between the stop
25
and member
11
so that vibrations or oscillations from the acquard are not transmitted to the harness
15
whilst the stop
25
is in abutment with stop member
22
.
The vibration isolation connection is preferably defined by a lost-motion arrangement
30
whereby movements of the output member
11
within the range of movement V
0
are not transmitted to move the stop
25
. In
FIG. 1
, the range of movement V
0
is shown as having an upper limit corresponding to the maximum distance and a lower limit corresponding to the minimum distance which the output member
11
is displaced relative to stop
25
by the vibration of the Jacquard. The lost motion accommodated by this arrangement
30
preferably has an upper limit LM spaced by a distance LE from the stop
25
and which slightly exceeds the upper limit of V
0
such that when the output member
11
is is raised by a distance slightly greater than distance LE the stop
25
is raised from stop member
22
.
As shown in
FIG. 1
, the lost motion arrangement
30
may be in the form of a flexible inextensible member
32
which interconnects the output member
11
and the stop
25
. The inextensible member
32
has a length which extends for distance LE so that when stop
25
is in abutment with stop member
22
the inextensible member
32
is in a collapsed state. Once member
11
is raised to distance LE, the inextensible member
32
is fully extended and thereafter raises the stop
25
as the member
11
continues to rise.
It is common in Jacquard mechanisms for the output member
11
to be biased downwardly onto a stop (not shown) to reside at its lower shed position. Accordingly, a resilient means
40
is preferably interconnected between the stop
25
and member
11
to provide a downwardly directed biasing force T for biasing the associated member
11
downwardly. The biasing force T is chosen to be sufficiently less than the biasing force T
H
in order to ensure that the stop
25
remains in abutment with stop member
22
.
Various embodiments are shown in
FIGS. 2
to
4
wherein similar parts have been designated by the same reference numerals throughout.
In
FIG. 2
, a first embodiment
50
is illustrated including a transmission member
51
in the form of an inextensible flexible cord
52
having a stop block
53
attached thereto. The stop block
53
may be moulded from a suitable plastics material and may be moulded onto the cord
52
. The stop block
53
defines stop
25
. The cord
52
has an upper portion
52
a
which terminates in an upper eye formation
55
to provide an anchorage point for a connector
56
which in turn is connected to an output cord
57
from the Jacquard mechanism (not shown). The portion
52
a
of the cord
52
between stop block
53
and eye formation
55
is of length LE in order to provide the lost motion connection.
An elasticated strip
41
which defines the resilient means
40
is connected between the stop block
53
and eye formation
55
. The elasticated strip
41
may for example be formed by one or multiple strands of elastomeric yarn such as LYCRA (RTM).
The cord
52
has a lower portion
52
b
which terminates in a lower eye formation
58
to provide an anchorage point for a connector
59
which in turn is connected to the harness cord(s)
16
.
The length of lower portion
52
b
is sufficiently long to enable the harness
15
to be raised to its upper shed position without eye formation
59
abutting the underside of stop member
22
.
The cord
52
may be of one continuous length or alternatively cord portions
52
a
,
52
b
may be separate and joined by or at the stop block
53
.
In the second embodiment
70
illustrated in
FIG. 3
, the upper cord portion
52
a
is replaced by a rigid elongate member
72
. In order to create lost motion the elongate member
72
is illustrated as being is connected to a rigid output connector
75
for the Jacquard mechanism by a pin
78
and slot
79
connection. The pin
78
and slot
79
are shown as being provided on the member
72
and connector
75
respectively but it will be appreciated that these may be reversed and be provided connector
75
and member
72
respectively if desired.
The length of slot
79
and its position relative to pin
78
is chosen to enable lost motion to occur over range V
0
. The lower end of slot
79
is positioned to engage pin
78
when the output connector
75
has been raised by distance LE from the stop block
53
. The resilient means
40
is in the form of a helical spring
76
which extends about and along the elongate member
72
; the spring
76
being connected at its opposite ends to the connector
75
and stop block
53
respectively.
Conveniently the elongate member
72
may be formed from a suitable plastics material and may be integrally moulded with the stop block
53
.
It is envisaged that the elongate member
72
may be pivotally connected to the output connector
75
and connected to the stop block
53
by a pin and slot connection similar to the pin and slot connection
78
,
79
.
In the third embodiment
90
illustrated in
FIG. 4
, the upper portion
52
a
is replaced by a strip member
91
which is resiliently extendable lengthwise. The strip member
91
shown is formed from a resilient material so as to undulate along the length of the strip. The material is resilient enough to cause the strip member
91
to assume its undulated, retracted, form when relaxed but flexible enough to enable the strip member
91
to extend to a maximum extended length whereat the strip member
91
is substantially flat. When at its maximum extended length, the strip member
91
becomes inextensible and so enables the Jacquard to raise the stop block
53
.
The strip member
91
may integrally include a stop face (not shown) at its lower end for abutment with stop member
22
. Accordingly, with such an arrangement, stop block
53
may be dispensed with.
It is to be appreciated that the effective distance LE which the Jacquard output needs to travel before lifting of the stop
25
is a relative distance and that in practice it is envisaged that the stop member
22
will be adjustably mounted to enable its height to be adjusted relative to the jacquard output. In this way, the stop member
22
may be raised/lowered relative to the Jacquard output to ensure that the fully extended length of the upper portion of the transmission member has an effective length corresponding to distance LE.
In the above embodiments the stop
25
is in the form of a stop block
53
which is fixedly attached to cord
52
and which, on lowering of the cord
52
, impacts against the stop member
22
. Such impacts are transmitted along cord
52
and in some cases may be undesirable.
As exemplified in
FIG. 5
, it is therefore envisaged that dampening means
80
may be provided in order to dampen the impact of the stop block
53
onto the stop member
22
.
In
FIG. 5
, the dampening means
80
includes a stop body
53
a
having an upper end
81
which may be connected to output member
11
by any of the lost motion arrangements
30
previously described.
The body
53
a
includes a piston cylinder
84
which is defined by an axially extending closed bore
82
which has a downwardly facing open end. A piston
86
is mounted on the stop
22
. Preferably the piston
86
is slidably received within the cylinder
84
over at least the range of movement V
0
.
The body
53
a
includes an axially extending guide rod
87
which projects beyond bottom stop face
53
b
of the body
53
a
and is slidably guided through a central bore
88
which extends axially through the piston
86
. The length of guide rod
87
is such as to ensure that the guide rod
87
remains within the piston
86
throughout the range of reciprocal movement between the upper shed US and lower shed LS positions of the member
11
.
Accordingly when the body
53
a
is lowered from the upper shed position toward the lower shed position, it is guided by the guide rod
87
such that the piston
86
enters into the piston cylinder
84
. In so doing, air within the piston cylinder
84
is trapped and compressed and so acts as a cushion to dampen motion of the stop body
53
a.
The degree of dampening required is determined by controlling the rate of escape of air from the piston cylinder
84
. This may be achieved by providing one or more bleed vents
89
in body
53
a
and/or providing a desired gap
89
a
between opposed faces of the piston
86
and cylinder
84
.
As the cylinder
84
vents, the body
53
a
is lowered in a dampened fashion until stop face
53
b
contacts stop member
22
.
It is envisaged that the piston may be provided on the stop body
53
and the piston cylinder be mounted on stop member
22
.
Claims
- 1. A drive transmission assembly for transmitting motive drive between a reciprocating drive member and a drive member in order to move the driven member in a path of reciprocal travel between first and second limits of reciprocal movement, the assembly including a drive transmission member connected to the drive member and the driven member in order to transmit said motive drive, a fixed stop member located within the path of reciprocal travel of said transmission member, the transmission member including a stop for abutment with said stop member in order to define said first or second limit of reciprocal movement for the driven member, said transmission member when connected to said drive and driven members defining a vibration isolating connection between said stop and said drive member whilst said stop is in abutment with said stop member.
- 2. An assembly according to claim 1 wherein dampening means are provided for dampening impact of the stop with said stop member.
- 3. An assembly according to claim 2 wherein the dampening means comprises a piston cylinder formed on the stop and a piston formed on the fixed stop member, the piston cylinder and piston co-operating to dampen motion of the stop towards the fixed stop.
- 4. An assembly according to claim 2 wherein the dampening means comprises a piston formed on the stop and a piston cylinder formed on the fixed stop member, the piston and piston cylinder co-operating to dampen motion of the stop towards the fixed stop.
- 5. An assembly according to claim 1 wherein the transmission member is in the form of an elongate flexible inextensible member connected at opposite ends to the drive member and stop respectively, the flexible inextensible member being longer than the distance between the drive member and the stop when the drive member is located at its limit position of reciprocal motion which is closest to the fixed stop member and the stop is in abutment with the fixed stop member.
- 6. An assembly according to claim 5 wherein biasing means are provided between the drive member and stop such that the drive member is biased toward the stop when the stop is in abutment with the fixed stop member and the drive member is located at its limit of reciprocal movement which is closest to the fixed stop member.
- 7. An assembly according to claim 1 wherein the transmission member is an elongate rigid member connected at opposite ends by first and second connection formations to the drive member and stop respectively, at least one of said connection formations permitting axial movement of the rigid member relative to the stop or drive member when the stop is in abutment with the fixed stop and the drive member is located at its limit position of reciprocal motion which is closest to the fixed stop member.
- 8. A jacquard machine including a plurality of output members interconnected to a plurality of heralds, each said output member being connected to one of said healds by a drive transmission assembly according to claim 1.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9718987 |
Sep 1997 |
GB |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/GB97/03309 |
|
WO |
00 |
10/7/1999 |
10/7/1999 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO99/13144 |
3/18/1999 |
WO |
A |
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3747647 |
Bergmann |
Jul 1973 |
|
5511588 |
Jak{haeck over (s)}ić |
Apr 1996 |
|
5636663 |
Lacrdix |
Jun 1997 |
|
Foreign Referenced Citations (5)
Number |
Date |
Country |
0051548 |
May 1982 |
EP |
0330624 |
Aug 1989 |
EP |
0374279 |
Jun 1990 |
EP |
2509333 |
Jan 1983 |
FR |
2510619 |
Feb 1983 |
FR |