GB2398618A

GB2398618A - Oscillatory drive assembly

Info

Publication number: GB2398618A
Application number: GB0303652A
Authority: GB
Inventors: John Dalton Griffith
Original assignee: Griffith Textile Machines Ltd
Current assignee: Griffith Textile Machines Ltd
Priority date: 2003-02-18
Filing date: 2003-02-18
Publication date: 2004-08-25
Anticipated expiration: 2023-02-18
Also published as: GB0303652D0; BE1018526A3; GB2398618B

Abstract

An oscillatory drive assembly 100 includes a continuous rotary input 1 which drives an oscillatory output 6 via first and second oscillatory drive transmissions. The first oscillatory drive transmission (cams 2 and 3, cam followers 11 and 12 and rocking body 10) creating a primary oscillatory motion of the output 6 and the second oscillatory drive transmission (cams 4 and 5, cam followers 19 and 20 and rocking lever 17, fig 3) creating a secondary oscillatory motion of the output 6 which is superimposed on the primary oscillatory motion. The amplitude of oscillation may be adjustable, preferably by an adjustable pivot.

Description

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AN OSCILLATORY DRIVE ASSEMBLY

The present invention relates to an oscillatory drive assembly.

s According to one aspect of the present invention there is provided an oscillatory drive assembly including a continuous rotary input which drives an oscillatory output via first and second oscillatory drive transmissions, the first oscillatory drive transmission creating a primary oscillatory motion of the output and the secondary oscillatory drive transmission causing a lo secondary oscillatory motion of the output which is superimposed on the primary oscillatory motion.

Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which: s Figure 1 is a perspective view of a drive assembly according to an embodiment of the present invention; Figure 2 is an end view of the drive assembly shown in Figure 1; Figure 3 is an end view similar to Figure 2 showing hidden detail.

so The drive assembly 100 shown in the Figures includes a rotary drive input in the form of a drive shaft 1 and an oscillatory output in the form of a lever end 6.

The assembly functions to convert a continuous rotary input into a desired oscillatory motion of the lever end 6. The oscillatory motion of the lever end 6 is a compound motion derived from a first oscillatory drive transmission which produces a primary oscillatory motion and a second oscillatory drive transmission which produces a secondary oscillatory motion which is superimposed on the basic oscillatory motion. À À À À

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Preferably the second oscillatory drive transmission is adjustable for varying the amplitude of the secondary oscillatory motion.

The lever end 6 is formed on a lever 61 which is rotatably mounted via a s bearing 8a on a stub shaft 8 fixed mounted in a rocking body 10. The stub shaft 8 and bearing 8a collectively define a first pivot about which the lever 61 oscillates.

The rocking body 10 is rotatably mounted via a bearing 7a on a stub shaft 7 lo which is fixedly secured to a mounting frame (not shown) for the assembly.

The stub shaft 7 and bearing 7a collectively define a second pivot about which the rocking body 10 oscillates.

Mounted on the rocking body 10 on opposite sides of the second pivot are is two cam followers 11,12. Cam followers 11,12 ride on respective cams 2, 3 mounted on the drive shaft 1. Cam 11 acts to move the rocking body 10 in an anti-clockwise direction about the second pivot and the cam 12 acts to move the rocking body 10 in a clockwise direction about the second pivot.

Cams 11,12 are therefore opposed and can be operated at high speed to JO cause high speed oscillatory motion of the rocking body 10 and in turn the lever end 6 carried by the rocking body 10. The cams 2,3; the cam followers 11,12 and rocking body 10 constitute the first oscillatory drive transmission for providing the primary oscillatory motion to the lever end 6.

as The second oscillatory drive transmission is defined by a rocking lever 17 which is pivotally connected to the lever 61 via a link rod IS. The rocking lever 17 is rotatably mounted via a shaft 18 and bearing 18a on a support bracket 30. The support bracket is in turn fixedly mounted on a frame (not shown). The shaft 18 and bearing 1 8a collectively define a third pivot about so which the rocking lever 17 oscillates. i À À À À

e. :: e:. e. : : :: À À À À À . Oscillatory motion of the rocking lever 17 is preferably created by a pair of cam followers 19,20 which ride upon respective cams 4,5 mounted on the drive shaft 1.

The cam followers 19,20 are located on opposite sides of the third pivot so that cam follower 19 acts to rotate the lever 17 in a clockwise direction about the third pivot whilst cam follower acts to rotate the lever 17 in an anti-clockwise direction about the third pivot. Accordingly the cam lo followers 19,20 are in opposition and so can operate at high speed.

The oscillatory motion of the rocking lever 17 is transmitted to the lower end of lever 61 via a fourth pivotal connection defined by a stub shaft 9 and bearing 9a. Preferably the fourth pivot is located to be close to the first pivot such the when the rocking body l0 oscillates about the first pivot there is only a small additional displacement of the lever end 6 brought about by the lever 61 being caused to rotate about the second pivot due to movement of the rocking body 10.

to The amplitude of the oscillatory motion imparted by the rocking lever 17 is preferably adjustable by pivotally attaching the link to the lever 17 via a movably pivotal connection. Preferably the movable pivotal connection is defined by a threaded stub shaft 16 and bearing 16a, the shaft 16 being located in a slot 21 formed in the lever 17 so that the distance of the movable pivot from the third pivot may be adjusted. The threaded shaft 16 has a nut 16b located on the opposite side of the lever 17 which may be tightened to fix the longitudinal position of the shaft 16 in slot 21 or loosened to permit the longitudinal position of the shaft 16 in slot 21 to be adjusted. i

Claims

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1. An oscillatory drive assembly including a continuous rotary input which drives an oscillatory output via first and second oscillatory drive s transmissions, the first oscillatory drive transmission creating a primary oscillatory motion of the output and the secondary oscillatory drive transmission causing a second oscillatory motion of the output which is superimposed on the primary oscillatory motion.

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2. An assembly according to Claim 1 wherein the second oscillatory drive transmission is adjustable for varying the amplitude of the secondary oscillatory motion.

3. An assembly according to Claim 1 or 2 wherein the output is defined by an end of a driven lever which is pivotally mounted on a rocking body, the rocking body being oscillated about a second pivot by said first oscillatory drive transmission and the driven lever being oscillated about a first pivot by said second oscillatory drive transmission.

4. An assembly according to Claim 3 wherein the first oscillatory drive transmission includes a pair of cam followers which ride on respective cams driven by said rotary input, the cam followers being mounted on the rocking body at locations on opposite sides of said second pivot so as to be in opposition with one another.

5. An assembly according to Claim 3 or 4 wherein the second oscillatory drive transmission includes a rocking lever which oscillates about a third pivot, the rocking lever being pivotally connected to the driven lever so as to cause it to oscillate about the fourth pivot.

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6. An assembly according to Claim 5 wherein the second oscillatory drive transmission includes a pair of cam followers which ride on respective cams driven by said rotary input, the cam followers being mounted on the rocking lever at locations on opposite sides of the third pivot so as to be in opposition to one another.

7. An assembly according to Claim 5 or 6 wherein the rocking lever is connected to the driven lever by a link, one end of the link being pivotally connected to the driven lever by a fourth pivot.

8. An assembly according to Claim 7 wherein the fourth pivot is located adjacent to the second pivot.

9. An assembly according to Claim 7 or 8 wherein the opposite end of Is said link is connected to the rocking lever via a movable pivot, the location of the movable pivot being adjustable relative to the third pivot in order to adjust the amplitude of oscillatory motion transmitted by said link.

10. An oscillatory drive assembly substantially as herein described with so reference to and as illustrated in the accompanying drawings. s