GB2211262A

GB2211262A - Reciprocating drive mechanism

Info

Publication number: GB2211262A
Application number: GB8724530A
Authority: GB
Inventors: David Arthur Pritchard
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-10-20
Filing date: 1987-10-20
Publication date: 1989-06-28
Anticipated expiration: 2007-10-20
Also published as: GB8724530D0; GB2211262B

Abstract

A reciprocating drive mechanism having a stroke of adjustable length comprises a crank wheel 1 and a connecting lever 2 pivoted at one end to the crank wheel and having a driving link 3 at its opposite end connecting the lever to the means driven by the mechanism, in this case, the shaking container 4 of a shaking machine. Pivoted guide means 13 for the lever 2 permits the lever to move or slide longitudinally and also rock in response to rotation of the crank wheel 1. The position of the guide means 13 is adjustable towards and away from the crank wheel by means of a hand wheel 22 and a lead screw 21 so as to vary the position of the fulcrum about which the lever 2 pivots and, hence, the length of the stroke produced by the driving link 3. <IMAGE>

Description

'BECIPR@CATING DRIVE KECHAKISM' The present invention relates to a recaprosating drive mechanism and, more particularly, to such a mechanism in which the length of the stroke of a reciprocating drive member is adjustable.

In apparatus driven by a reciprocating mechanism, such as, a shaking rachine, it is nct only desirable to adjust the frequency of the oscillation produced by the mechanism but also the amplitude of the oscillatiens. Accordingly, it is an object of the present invention to provide a reciprocating drive mechanist In which the stroke of a recirprocating olive mere is readily adjustable so as to enable alteration in the amplitude of the oscillations produced by the mechanism.

The present invention consists in a reciprocating drive mechanism having a stroke of adjustable length, comprising a driven crank meKosr, a connecting lever pivoted to the crank member, guide means for the lever which permits the lever to move longitudinally and rock in response to rotation of the crank member, means for adjusting the guide means generally longitudinally of the lever, and a driving link pIvoted to the lever on the opposite side of the guide means to the crank member for coupling the lever to driven means constrained to reciprocate along a path transversely to the path of adjustment of the guide means.

Adjustment of the guide means alters the position of the fulcrum about which the lever can rock in response to rotation of the crank member, thereby changing the ratio of the lengths of the lever arms and the length of the strcke of the driving WIth the present invent ion, this adjustment may no effectec whilst the mechanism is operating.

In one preferred embodiment, the guide means is adapted to constrain the lever. to move or slide longitudinally and is pivoted to permit rocking move- ment of the lever about an axis substantially parallel to the rotational axis of the crank.The means for adjusting the guide means is arranged to move fle piveted quide means to and fre generally longitudinally 0 the lever Conveniently, tne quide means is pivoted on a carriage which is slidably guided for movement towarde and away from the crank under the control of the adjusting means which may, for example, be a manually operated lead sore":.

The pivoted guide means may have guide wheels engaging the lever ano constraining the lever to move er slide in its longitudinal direction.

The means driven ry the reciprocating mechanism, for example, the container of a shaking machine, may be mounted for reciprocating movement by a mounting member attached thereto and engagIng ano supported by gulch wheels. The driving link of the reciprocating mechanism couples the connecting lever to this mounting member.

With the present invention, the guide means may be adjusted to vary the amplitude of the oscillations of the means driven via the link by the reciprocating mechanism, and the speed of the reciprocating mechanism and, hence, the frequency of the oscillations, may be varied by driving the crank from an adjustable speed motor, such as, an adjustable speed electrical motor.

In order that the present invention may be ore readily understood, reference will now be mace to the accompanying drawings, in which:- Figure 1 is a schematic elevational view of a shaking machine embodying the invention, and Figure 2 is a schematic plan view of the machine.

Peferring to the drawings, the reciprocating mechanism of the machine comprises a crank wheel 1, a connecting lever 2 pivoted at one end te the crank wheel and having a driving link 3 at its opposite en connecting the leer te the shaking container 5 cf the machine. The container 4 is adapted to hold items to be shaken, such as, bottles of 1 iquid.

Pivoted guide means 5 for the lever 2 permits the lever to move or slide longitudinally an alsc rock in response to rotation of the crank wheel 1. The position of the guide means 5 is adjustable generally longitudinally of the lever 2 and towards and awav from the crank wheel so as to vary the position cf the fulcrum about which the lever pits and, hence, the length of the stroke produced by the driving link 3.

The crank wheel 1 is mounted on the upper end of a vertical axle 6 rotatably supported by bearings 7 fixed to the machine frame 8, and it is driven by a geared DC electrical motor 9 via a belt drive 10 and a pulley 11 fixed to the lower end of the axle.

The connecting ever 2, which comprises a flat bar of rectangular cross section, is connected te the crank wheel 1 by a pivot 12 disposed at a suitably eccentric position on the crank wheel and is guided ano supported for longitudinal movement In â generally horizontal plane by the guide means 5. The latter comprises a rectangular guide plate 13 on which are mounted two pairs er spaced guide wheels 14 which are rotatable about vertical axes. The lever projects between the guide wheele and has a plate 1 V-shaped longitudinal edges 16 fixed to its unwersice.

The edges of this plate project beyend the edges cf the lever and engage In V-shaped grooves 17 in the guide wheels 14 so that the lever is guided for free longitudinal movement. The guide plate 13 is pivotally supported on carriage 18 mounted below the plate by means of a pivot 19 disclosed generally centrally of the guide plate. The carriage 18 is slidably mounted on two horizintal guide rods 20 supported on the machine rame 8 and projecting through passages in the carriage. Wne carriage is adjustable along the guide rods by a lead screw arrangement, the lead screw 21 of which can be manually turned by a hand wheel 22 fixed to one end of the lead screw.

The shaking container 4 is located to one side of the guide rods 20 and has a mounting member 23 which is guided for reciprocating movement transversely to the path of adjustment of the carriage 18. The mounting member 23 comprises a bar fixed to the bottom of the container 4 and has a plate 24 secured to its underside, which plate has V-shaped longitudinal edges 25 projecting from the edces of the mounting member. These V-shapea edges engage with V-grooves 26 in two pairs of spaced guide wheels 2, mounted on the machine frame 8 for rotation about vertical axes so that the shaking container z can reciprocate freely.

The driving link 3 has one eno pivoted to the connecting lever 2, at 28, and its opposite end pivoted to the container mounting er 23 oy a pivot 29.

When the machine is operating,the movement of the connecting lever 2 in response to rotation of the driven crank wheel 1 is controlled by the pivoted guide plate 13. The latter constrains the lever to move or slide longitudinally whilst rocking about the pivot 19 of the guide plate. The rockling movement of the lever reciprocates the driving link 3 and, hence, oscillates the shaking container 4. The amplitude of the oscillations of the container 15 dependent on the stroke of the link 3 which, in turn, is dependent on the amount of transverse movement of the adjacent end of the lever 2 as it rocs about the guide plate pivot 19. By moving the pivot 19 longitudinally of the lever, this transverse movement can be increased or decreased. The pivot position is adjustable towards and away from the crank wheel by moving the carriage 18 along the guide rods 20 by turning the lead screw 21 with the hand wheel 22. This adjustment may be made either whilst the reciprocating mechanism is stopped or operating. Aditionally, the frequency of the container oscillations may be adjusted by varying the speed of the motor G driving the cranY wheel 1.

Whilst a particular embodiment has been described, it ill be understood that modifications can be made without departing from the sccpe of the invention.

Claims

1. A reciprocating drive mechanism having a stroke of adjustable length, comprising a driven crank member, a connecting lever pivoted to the crank member, guide means for the lever which permits the lever to move longitudinally and rock in response to rotation of the crank member, means for adjusting the guide means generally longitudinally of the lever, and a driving link pivoted to the lever on the opposite side of the guide means to the crank member for coupling the lever to driven means constrained to reciprocate along a path transversely to the path of adjustment of the guide means.

2. A drive mechanism as claimed in claim 1, wherein the guide means is adapted to constrain the lever to slide longitudinally and is pivoted to permit rocking movement of the lever about an axis substantially parallel to the rotational axis of the crank member, and wherein the means for adjusting the guide means is arranged to move the pivoted guide means to and fro generally longitudinally of the lever.

3. A drive mechanism as claimed in claim 2, wherein the guide means is pivotally mounted on a carriage which is slidably guided for movement towards and away from the crank member under the control of the adjusting means.

4. A drive mechanism as claimed in claim 3, wherein the pivoted guide means had guide wheels cooperating with the lever and constraining the lever to move or slide in its longitudinal direction.

5. A drive mechanism as claimed in any one of the preceding claims, wherein the adjusting means is a manually operated lead screw.

6. A drive mechanism as claimed.in any one of the preceding claims, wherein the driving link couples the connecting lever to a mounting member for the driven means, which mounting member is slidably guided for reciprocating movement by guide wheels engaging and supporting the mounting member.

7. A drive mechanism as claimed in any one of the preceding claims, wherein the crank member is driven by an adjustable speed motor.