GB2198807A - Vibrator mechanisms - Google Patents

Abstract

A vibrator mechanism includes a finger (9) which rides on a disc (7) which is bolted to one end of a shaft (1) so as to rotate eccentrically about the axis of the shaft (1) as the shaft (1) rotates. The other end of the finger (9) is pivoted, for rotation about an axis (A), to a housing (3) of the shaft (1). As the shaft (1) rotates the eccentric rotation of the disc (7) causes the finger (9) to oscillate about the axis (A). A roller (15) mounted in a block (13) rests on the finger (9) at the point at which the oscillating motion of the finger (9) is to be transferred by the block (13) to a member (12) to be vibrated. A telescopic ram (17) moves the block (13) and hence point of rest of the roller (15) on the finger (9) along the length of the finger (9) and thereby alters the amplitude of the vibrations transferred to the member (12). <IMAGE>

Description

Vibrator Mechanisms This invention relates to vibrator mechanisms.

It is an object of the present invention to provide a vibrator mechanism of such a form as to facilitate control of the amplitude of the vibrations.

According to the present invention there is provided a vibrator mechanism comprising: a first member arranged for pivotal motion about an axis; drive means for causing oscillatory motion of said first member about said axis; actuator means for transferring motion of a selected location on said first member to a member to be vibrated; and setting means for varying the position on said first member of said selected location thereby to vary the distance of said selected location from said axis and hence the amplitude of the vibrations of said actuator means.

Preferably said actuator means contacts said first member at said selected location.

In such an arrangement said actuator means preferably comprises first and second sections and resilient means effective to urge said first and second sections apart and thereby tend to maintain said actuator means in contact with said first member in operation.

One vibator mechanism in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a part sectioned side elevation of the vibrator mechanism; Figure 2 is an end elevation of part of the mechanism; and Figure 3 is a sectional view of part of the mechanism along the line III-III in Figure 1.

Referring to the drawings, the mechanism includes a drive means comprising a shaft 1 mounted in a housing 3 bolted to a frame 5 for axial rotation by means of a prime mover (not shown) e.g. an electric motor. A disc 7 is bolted to one end of the shaft 1 so as to rotate eccentrically about the axis of the shaft 1 as the shaft 1 rotates.

A finger 9 pivoted at one end to the housing 3 about an axis A rides on the disc 7 so as to experience oscillatory motion about the axis A as the shaft 1 rotates. A spring 11 connected between the finger 9 and the housing 3 maintains the finger 9 in contact with the disc 7.

The mechanism further includes an actuator means whereby the oscillatory motion of a selected location on the finger 9 is transferred to a member 12 to be vibrated.

The actuator means includes a block 13 on which is mounted a roller 15 for rotation about an axis B, the roller 15 resting on the finger 9 at the selected location. A spring-loaded telescopic arm 8 which is pivoted at one end to the member 12 for rotation about an axis C connects the block 13 to the member 12, the arm 8 comprising first and second coaxial sections 2, 4 which are urged apart from one another by springs 10 dispersed around the inner section 2 parallel to the axes of the arm 8.

The position of the location at which the roller 15 rests on the finger 9 is controlled by a setting means comprising a pneumatically operated telescopic arm 17 pivotally connected at one end to the block 13 by way of a spherical bearing 14, and pivotally connected at its other end to the frame 5.

Movement of the position of contact between the roller 15 and the finger 9 in a direction away from the axis A is limited by contact between a further roller 19 mounted on the block 13 and an adjustable stop member 21 mounted on the frame 5.

In operation, as the shaft 1 rotates, the finger 9 oscillates about the axis A producing corresponding reciprocating motion of the block 13 and the arm 8, and hence vibrating the member 12.

The frequency of vibration is controlled by control of the speed of the drive prime mover.

The amplitude of the vibration is controlled by operation of the telescopic arm 17, the amplitude being infinitely variable between a maximum set by the stop 21 and substantially zero when the axes A, B and C are in line.

By arranging for the axes A,B and C to lie in line when the telescopic arm 17 is fully extended, rapid changes of the amplitude of vibration between zero and the maximum value set by the stop 21 are facilitated.

It will be understood that in use of the mechanism the member 12 will normally be connected to a further member to be vibrated which is mounted on to the frame 5, e.g. a conveyor along which articles are required to move in response to the vibrations, and that the motion of the further member will be subject to constraints so that the vibrations of the further member occur only in a desired direction.

Furthermore, the further member will be arranged to impose a force on the member 12 such as to urge the roller 15 towards the finger 9 in operation.

The arm 9 is of spring-loaded telescopic form to help maintain the roller 15 in contact with the finger 9. If the arm 8 is of fixed length the roller 15 tends to bounce on the finger 9 so that the further member oscillates out of phase with the finger 9. For optimum operation the spring rate of the springs 10 taken together is made as nearly as possible equal to the effective spring rate of the weans whereby the further member is mounted on the frame 5. A lower rate means that a given amplitude of oscillation of the finger 9 gives a smaller amplitude of oscillation of the further member and vice versa. The springs are also made capable of sustaining more than the running load since the force required to accelerate the further member on start-up is considerably higher.

It will be further understood that whilst the mechanism described by way of example includes a stop 21, such a stop may be omitted in other mechanisms in accordance with the invention.

Similarly whilst in the mechanism described by way of example the actuating means contacts the finger 9 and the stop 21 via respective rollers 15 and 19, in other mechanisms in accordance with the invention such contact may be effected in other ways.

Claims (15)

1. A vibrator mechanism comprising: a first member arranged for pivotal motion about an axis; drive means for causing oscillatory motion of said first member about said axis; actuator means for transferring motion of a selected location on said first member to a member to be vibrated; and setting means for varying the position on said first member of said selected location thereby to vary the distance of said selected location from said axis and hence the amplitude of the vibrations of said actuator member.

2. A mechanism according to Claim 1 wherein said actuator means contacts said first member at said selected location.

3. A mechanism according to Claim 2 wherein said actuator means contacts said first member by means of a rotatable member mounted on said actuator means.

4. A mechanism according to any one of the preceding claims wherein said actuator means is pivotally connected to said member to be vibrated.

5. A mechanism according to any one of the preceding claims wherein said setting means comprises a telescopic arm connected between said actuator means and a member fixed with respect to said axis.

6. A mechanism according to Claim 5 wherein said arm is pivotally connected to said actuator means and said member fixed with respect to said axis.

7. A mechanism according to Claim 5 or Claim 6 wherein said arm is pneumatically operated.

8. A mechanism according to any one of the preceding claims further including stop means which sets a limit to the variation of said distance by said setting means.

9. A mechanism according to Claim 8 wherein said stop means is arranged to contact said actuator means when said distance is at said maximum.

10. A mechanism according to Claim 9 wherein said stop means contacts said actuator means by way of a rotatable member mounted on said actuator means.

11. A mechanism according to any one ofthe preceding claims wherein said drive means comprises a second member mounted for rotation eccentrically about an axis spaced from said pivotal axis of said first member, and said first member rests against said second member.

12. A mechanism according to Claim 11 wherein said first member is urged into contact with said second member by means of a spring.

13. A mechanism according to any one of Claims 2 to 12 wherein said actuator means comprises first and second sections and resilient means effective to urge said first and second sections apart and thereby tend to maintain said actuator means in contact with said first member in operation.

14. A mechanism according to Claim 13 wherein first and second sections and resilient means together constitute a spring-loaded telescopic arm.

15. A vibrator mechanism substantially as hereinbefore described with reference to the accompanying drawings.