METHOD OF DRIVING HEALD FRAME FOR NEGATIVE DOBBY MACHINE, NEGATIVE CAM MACHINE

Abstract

 A method of driving a heald when flexible transmission members (3a, 3b), such as ropes or the like, connected to the shedding levers of a negative dobby machine, negative cam machine, etc. are provided above a heald frame (11). The flexible transmission members (3a, 3b) and the heald frame (11) are connected via operation levers (4a, 4b) arranged at the side or above the heald frame (11) and a connecting rod (8) or the like, so that the spring tension acting on the heald frame (11) is small and the members (3a, 3b) and an operation member (2) for the negative dobby machine body, negative cam machine body, etc. less wear in case that the tension of the falling warp is larger than the tension of a lifted warp. The heald frame (11) is lowered by the tension of the members (3a, 3b) and raised by the force of spring (13) arranged above or beside the heald frame (11)

Description

Technical Field

[0001] This invention relates to driving method for moving a heald frame up and down in negative dobby machines or negative cam machines installed to looms.

Background Art

[0002] In prior art, when resilient transmission member such as ropes connected to a shedding lever of negative dobby machines or cam machines is disposed above a heald frame, heald frame driving method is performed by raising the heald frame using tension of the rope and depressing it using spring restoring force. In this driving method, however, for example, when spun yarn fabric is woven in refined clothing fashion, if tension of downward warp is made larger than that of upward warp, spring tension must be increased. Since the heald frame is raised against the above mentioned spring tension, large strength acts on the rope and on the negative dobby machine body or the negative cam machine body, thereby abrasion is accelerated in such part and power is lost. Moreover, since the spring and members relating to this are disposed below the heald frame, treatment is inconvenient and workability is not favorable.

Disclosure of Invention

[0003] This invention is characterized in heald frame driving method when resilient transmission member such as rope connected to a shedding lever of negative dobby machines or cam machines i; disposed above a heald frame, wherein the resilient transmission member is engaged with the heald frame through a working lever, a connecting rod or the like, driving is effected so that the heald frame is moved downwards by tension of the resilient transmission member and upwards by restoring force of a spring, and the operating lever, connecting rod, spring and the like are arranged at lateral side or upper side of the heald frame.

[0004] An object of this invention is to provide heald frame driving method wherein spring tension acting on a heald frame is small when tension of downward warp is less than that of upward warp, and abrasion is small at resilient transmission member at working member such as negative dobby machine body or cam machice body.

[0005] Another object of this invention is to provide heald frame driving method, wherein the working lever, connecting rod and spring to engage the resilient transmission member with the heald frame are arranged at lateral side or upper side of the heald frame, and treatment and adjustment are easy.

[0006] Still another object of this invention is to provide heald frame driving method wherein power loss is small.

[0007] Above mentioned and other objects and features of this invention will be apparent from the following description referring to the accompanying drawings.

Brief Description of the Drawings

[0008] Fig. 1 is a schematic front view of an embodiment of tnis invention.

Best Mode Carrying Out the Invention

[0009] Fig. 1 shows an Embodiment of method according to this invention. In the figure, a negative dobby machine body 2 is mounted on the right end of upper surface of a top beam 1 of a loom, and a plurality of heald frames 11, which correspond to a plurality of shedding levers (not shown) of the negative dobby machine body 2 and have the same number as that of the shedding levers, are arranged in longitudinal direction. One shedding lever is connected to two ropes 3a, 3b for one heald frame 11 corresponding thereto.

[0010] The top beam 1 of the loom is provided with pins projecting on leftward and rightward portions from the center of the beam, and a plurality of guide pulleys 15a, 15b corresponding to the heald frames 11 are rotatably supported by respective pins. Shafts 10 project respectively on both side frames 9a, 9b of the loom at sideward portion of the heald frames 11, and a plurality of working levers 4a and 4b are pivotally supported respectively by the shafts 10 corresponding to each heald frame 11. The working levers 4a and 4b are formed in lateral symmetry and provided with sector portions 5a, 5b on upper side, connecting portions 6a, 6b on inner side, and arms 7a, 7b on outer side, the rope 3a guided by the guide pulley 15a is connected to the sector portion 5a;the rope 3b guided by the guide pulley 15b is connected to the sector portion 5b.

[0011] Connecting rods8, 8 are joined with pins respectively to the connecting portions 6a, 6b, and each of the connecting rods 8, 8 stands upright and the bottom and thereof is pivotally connected to the heald frame 11.

[0012] Hooks 12, 12 are joined with pins respectively to outer ends of the arms 7a, 7b, and brackets 14a, 14b are installed below the arns 7a, 7b in opposing relation thereto.

[0013] The brackets 14a, 14b are attached to the side frames 9a, 9b, and two tension coil springs 13 are stretched between the hooks 12, 12 and the brackets 14a, l4b respectively.

[0014] In the negative dobby machine as above constituted, when the shedding lever (not shown) of the negative dobby machine body 2 oscillates and the ropes 3a, 3b are pulled, the left working lever 4a rotates in clockwise direction against torque of the coil spring 13 and the right working lever 4b rotates in counterclockwise direction, thereby the heald frame 11 is moved downwards through the connecting rods 8, 8, When the shedding lever is restored, both working levers 4a, 4b are also restored by means of restoring force of the coil spring 13, thereby the heald frame is moved upwards. Since longitudinal position on upper side of the heald frame 11 is defined by the connecting rods 8, the heald frame 11 is provided with a guide member (not shown) only at lower side thereof. In order to refine clothing fashion in spun yarn fabric, distance from shedding neutral position (i.e position where w^prp is displaced neither upwards nor downwards by means of the heald) to downward war:. position is set larger than that to upward warp position. Accordingly, tension in downward warp is larger than that in upward warp therefore the tension coil spring 13 with less tension may be used there.

[0015] As a result, force applied to the rope or the negative dobby machine body 2 in order to drive the heald frame 11 against the spring tension becomes small.

[0016] Although above mentioned embodiment is described regarding a negative dobby machine, similar function is obtained when the negative dobby machine body 2 is replaced by a negative cam machine body in the above mentioned embodiment.

[0017] Moreover, the tension coil spring 13 in the above mentioned embodiment may be replaced by another tension coil spring connecting the heald frame 11 with the top beam 1.

Claims

Heald frame driving method in negative dobby machines or cam machines, wherein resilient transmission member such as ropes connected to a shedding lever of negative dobby machines or cam machines is disposed above a heald frame which is driven, characterized in that the heald frame is connected to the r. sillent transmission member through a working lever, a connecting rod and the like which are arranged at lateral side or upper side of the heald frame, and driving is effected so that the heald frame is moved downwards by pulling the resilient transmission member using the shedding lever and it is moved upwards by a spring arranged at lateral side or upper side of the heald frame when the shedding lever is restored.

Drawing