GB2151000A

GB2151000A - Vibratory conveyor

Info

Publication number: GB2151000A
Application number: GB08429525A
Authority: GB
Inventors: Richard Bruce Kraus; Albert Musschoot
Original assignee: General Kinematics Corp
Current assignee: General Kinematics Corp
Priority date: 1983-12-09
Filing date: 1984-11-22
Publication date: 1985-07-10
Also published as: JPS60157413A; DE3444747A1; SE8406226D0; AU3561884A; SE8406226L; GB8429525D0; NO844916L

Abstract

In a vibratory conveyor having a resiliently supported trough for material and two transversely mounted eccentric mass exciter drive assemblies 30, 32. Only one drive assembly is driven at any time to impart a vibratory force to the trough along a straight line path, the improvement being a supporting structure for each drive assembly which rigidly supports the drive assembly relative to the trough in the straight line path and resiliently supports the drive assembly transverse to the straight line path. The supporting structure comprises spaced, planar flexible straps or plates 50 extending transverse to the longitudinal axis of the trough and parallel to the plane containing the motor centre line and the trough center of gravity. The straps are rigid in the direction of movement of the trough and flexible in the direction transverse thereto. In an alternative embodiment each vibratory apparatus is pivotally connected to the trough and a portion of the motor remote from the pivot is suspended from the trough by a coil spring directed transverse to the straight line path. <IMAGE>

Description

SPECIFICATION Vibratory conveyor Background of the Invention Field of the Invention This invention relates to a vibratory conveyor and more particularly to a structure for isolating detrimental vibrations tending to diminish the conveying action of the apparatus.

Description of the Prior Art In conventional vibratory conveyors, as exemplified by that shown in U.S. Patent 3,089,582, to Musschoot, a feeder trough is resiliently mounted on a support and receives a supply of material to be conveyed. An exciter drive assembly for the trough consists of an exciter frame mounted on a drive housing, which housing is carried by the trough with the exciter frame mounted between heavy duty rubber shear springs. A motor having eccentric weights at the opposite ends of a drive shaft is mounted on the exciter frame. Operation of the motor imparts a straight-line vibratory movement to the trough, serving to advance the material along the trough. Forces are generated by the motor transverse to the aforesaid straight line movement, which transverse forces are absorbed in large part by the shear springs.The transverse forces counteract the forces advancing the material along the trough necessitating a larger motor to develop a suitable advancing or conveying movement.

The shear springs of the Musschoot patent went a long way in solving the problem of dealing with the transverse forces, however by so doing the desired straight-line forces are somewhat damped as well so that a larger exciting capability was required.

Further, prior art conveyors are generally capable of advancing material in but a single direction. This seriously limits their utility.

The present invention is specifically directed to overcoming the above-identified problems.

Summary of the Invention The present invention is an improvement in a vibratory conveyor of the type having a resiliently supported trough for conveying material. A pair of exciter drive assemblies are mounted on the trough and are oriented at 90 to each other. Only one exciter drive assembly is driven at any one time to impart a vibratory force to the trough substantially along a straight line path in a particular direction to advance the material on the trough.

The improvement resides in a supporting structure for each exciter assembly which supporting structure rigidly maintains the associated exciter drive assembly relative to the trough for straight line movement of the material and resiliently supports the associated exciter drive assembly in a direction transverse to the straight line movement.

It is a principal object of the present invention to positively transmit in-line forces to the trough and to isolate or absorb forces transverse to the in-line forces.

In a preferred form, each supporting structure comprises spaced, planar members extending transverse to the vertical plane containing the longitudinal axis of the trough and lying parallel to the plane containing the axis of the motor and the center of gravity of the trough. The planar members substantially rigidly support and directly transfer vibratory motion to the trough in the straight line path and are resilient or flexible in the direction transverse to the plane of the planar members to isolate or absorb vibratory motion transverse to the straight line path. Vibrational flexing of the members transverse to the plane of the planar members is permitted whereby the detrimental forces created thereby are isolated or absorbed.Those forces transferred to the other non-operative exciter drive assembly are in a direction transverse to the planar members of said nonoperative exciter drive assembly and as such are isolated or absorbed by said planar members of the non-operative exciter drive assembly.

In an alternative embodiment, the exciter drive assemblies are pivotally connected at the underportion of the trough and a portion of each exciter drive assembly remote from the pivotal connection is suspended from the trough by a spring directed transversely to the in-line forces. The spring action is analogous to the flexing of the planar members so that the operation of each embodiment is, in theory, the same.

In another aspect of the invention, movement of the material in the trough can be selectively accomplished in either direction by deenergizing one exciter drive assembly and activating the other exciter drive assembly.

Other features and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings.

Brief Description of the Drawings Fig. 1 is a side elevation view of a vibratory conveyor or feeder embodying the invention; Fig. 2 is a sectional view of the vibratory conveyor taken along line 2-2 of Fig. 1; Fig. 3 is a side elevation view of an alternative construction of a vibratory conveyor embodying the invention; Fig. 4 is a fragmentary sectional view of a connection between the exciter drive assembly and the conveying trough taken along line 4-4 of Fig. 3.

Description of the Preferred Embodiment In an exemplary embodiment of the invention, depicted in Figs. 1 and 2, a vibratory con veyor or feeder, designated 10 is shown and includes generally a trough 1 2 resiliently supported by springs or the like 14 on a base 1 6.

The trough 12, as seen most clearly in Fig. 2, comprises a conveying surface 1 8 with spaced, diverging lateral walls 20. The trough 1 2 has unobstructed free ends 22,24 each of which serves as a suitable loading or discharge area. To suspend the trough 1 2 from the base 14, brackets 26 are provided on the walls 20 in contact with the springs 14 on the base 16. The springs 14 could be coil springs, rubber blocks or the like.

A mounting frame or mount 28 for two separate exciter drive assemblies 30 and 32 is affixed to the midportion of the trough and has a pair of supporting walls 34,36 disposed in such a way that the planes of the walls intersect at right angles to each other. The planes of the walls 34,36 are perpendicular to the vertical plane containing the longitudinal axis of the trough 1 2. U-shaped channels 38,40 laterally span the walls 34,36, respectively, and are anchored securely thereto. The channels 38,40 open away from the mount 28 so that the flanges 42 on channel 38 and flanges 44 on channel 40 provide mounting surfaces for the respective exciter drive assemblies 30,32.

The exciter drive assemblies 30,32 and the support structures 46 for each are substantially identical so only one will be described in detail, that is, only support structure 46 for drive assembly 30 will be described in detail, it being understood that the support structure for drive assembly 32 will be the same.

The support structure 46 is provided for supporting exciter drive assembly 30 from the mount 28 on the trough. The support structure 46 comprises a channel shaped platform 48 and four planar straps 50, each strap having a rectangular configuration. Each strap 50 is suitably secured at one end to the flanges 42 of the channel 38, as by bolting.

The flanges 42 on channel 38 are substantially parallel so that the straps 50 at each side of the drive assembly 30 reside in the same parallel relationship. The ends of the straps 50 remote from the channel 38 are attached to the platform 48 by being bolted to flanges 54 of the platform 48. The channel shaped platform 48 is substantially identical to and opens toward the channel 38. The flat upwardly facing surface 56 of the platform 48 carries its respective exciter drive assembly 30.

Each exciter drive assembly 30,32 comprises a drive motor 58 having a rotatable shaft 60 carrying at its opposite ends an eccentric counterweight 22. The axis of the shaft 60 lies parallel to the planes of the straps 50 and extends transverse to the vertical plane containing the longitudinal axis of the trough. The axis of the motors 58 of exciter assemblies 30 and 32 lie in planes that intersect at right angles at the center of gravity (C.G.) of the system. The center of gravity (C.G.) of the system lies in the vertical plane containing the longitudinal axis of the trough 1 2. Using the exciter assembly 30 on the left in Fig. 1 for illustration purposes, it can be seen that the vibratory forces generated by the rotating counterweights 62 act on the support structure 46 along the planes of the straps 50 to the trough.The force can be illustrated schematically in Fig. 1 as a force 64 generally along a straight-line path. The exciter assembly 30 also generates a vibratory force in a direction transverse to the straightline path.

According to the prior art apparatus using only one exciter drive assembly, the vibratory force component transverse to the vibratory force component along line 64 is a force tending to counteract the conveying force which, if used in two exciter drive assembly systems with only one exciter drive assembly 30 operating as shown in Fig. 1, would have a tendency to excite the second exciter drive assembly 32, adversely affecting the conveying action of the exciter assembly 30. However, according to the present invention, the flexible straps 50 tend to isolate and absorb the component force transverse to the straight line force 64. To accomplish this, the straps 50 are made of a flexible material, such as spring metal.In operation, the straps 50 are rigid in the plane of the straps and are flexible or will flex in the plane transverse to the plane of the straps as indicated by the phantom straps 51 in Fig. 1. The flexing of the straps will dampen and absorb the adverse transverse forces. In addition, when exciter assembly 30 is operating some of the vibratory forces (along line 64) are transmitted through mounting frame 28 to exciter assembly 32, but those forces will be transverse to the planes of the straps 50 of exciter assembly 32 and will therefore be absorbed or dampened. The straps 50 of exciter assembly 32 deflecting under the forces from exciter assembly 30 only slightly as shown by phantom lines 51'. Consequently, substantially the entire vibratory force along the horizontal path is realized from the exciter drive assembly 30 without the negating effect of forces acting transverse thereto.

In the illustrated form, each exciter drive assembly 30,32 is suspended by four straps 50. The desired vibration dictates the dimensions of each strap. The dimensions of the straps will also vary depending upon the type of material used and the size of the loads being conveyed. The number of straps 50 could be two or could be more depending on the load created by the exciter drive assembly and by the conveying demands of the apparatus. In addition to the aforementioned spring steel, other deflectable materials would function suitably. In addition to the requirement that the straps 50 be flexible enough to permit absorption of the transverse vibratory forces, they must also be stiff enough or rigid enough to support the support structure 46 and the exciter drive assembly 30.

It can also be seen that the arrangement of separate exciter drive assemblies 30,32 operating on perpendicularly arranged plates permits conveyance of particulate material in either direction along the trough. By selectively operating one exciter drive assembly in favor of the other, a preferred conveying direction can be chosen.

In an alternative embodiment of the invention illustrated in Figs. 3 and 4, the base 114, trough 11 2 and mounting frame or mount 1 28 are identical with those in the apparatus in Figs. 1 and 2. Two exciter drive assemblies 152,154 are provided and are similarly mounted so that the discussion herein is limited to the mounting and operation of one such exciter assembly 1 52.

The exciter drive assembly 1 52 has integral, spaced, parallel ears 90 best seen in Fig.

4. A mounting bracket 92 is fixed to each of the supporting walls 1 34 of the mount 1 28 and have ears 94 spaced to fit closely with the ears 90 associated with the exciter drive assembly 1 52. The ears 90,94 are overlapped and a pivot pin 96 extends through aligned bores 98 so that the vibratory apparatus 1 52 is freely and rotatably suspended about the axis of the pin which extends transverse to the vertical plane containing the longitudinal axis of the trough 11 2.

Integral with each ear 90 of the exciter drive assembly is a boss 100 having a through bore 102. A coil spring 103 connects between the bracket 1 26 beneath the trough 11 2 and extends through the bore 102 to engage the boss 100. Although two coil springs 103 are shown on each exciter drive assembly 1 52 and 154, it is understood that a boss could be located in the mid-portion of the motor of each exciter drive assembly so that only one spring 103 would be needed for each exciter drive assembly 1 52 and 1 54. In the passive, inoperative state, the length of the springs 103 are such as to position the exciter drive assemblies 1 52 or 1 54 in a plane that contains the axis of the motor shaft 160, the axis of the pin 96 and the center of gravity C.G.

The embodiment in Figs. 3 and 4 works substantially the same as that in Figs. 1 and 2. Through the pivot connection of the mount 1 28 and vibratory apparatus 152, the vibratory force is imparted along the straight line path 1 64 tending to convey the particulate material from left to right in Fig. 3.The component of force transverse to the straight line path 1 64 is isolated, dampened and absorbed by the coil spring 1 03. That part of the force transmitted through mount 1 28 to the exciter drive assembly 1 54 will be in a direction transverse to the line of force 1 64' of assembly 1 54 and will therefore be absorbed, isolated and dampened by spring 103 of assembly 1 54. Consequently, the same damping effect is achieved in this embodiment as in the prior embodiment. Further, the incorporation of separate exciter drive assemblies 152,154 makes possible the bi-directional conveyance of the particulate material.

In both embodiments, the natural frequency of the damping members 50,103 should be below the operating frequency of the motor.

The frequency of the damping member is so chosen that in the direction of vibration substantially all forces are transferred to the trough resulting in the full frequency of the motor acting on the trough. In the transverse direction the frequency of the spring being below the frequency of the motor dampens, absorbs and isolates the transverse forces.

This arrangement assures that substantially the entire component of vibratory force generated by the exciter assembly in operation is transferred along the intended lines 64, 1 64.

The foregoing disclosure and specific embodiments is illustrative of the broad inventive concept comprehended by the invention.

Claims

1. In a vibratory conveyor having a resiliently supported trough receiving and conveying material from one end thercof to the other, the improvement comprising: a first exciter drive means, a second exciter drive means, said first and second exciter drive means being operatively connected to said trough along axes that intersect at a right angle, one of said exciter drive means being energized to generate vibratory forces for moving the material along said trough; means for supporting each exciter drive means from said trough, said supporting means mounting said exciter drive means substantially rigidly in a direction parallel with the direction of movement of said material and substantially flexibly in a direction transverse to said direction of movement of material;; said vibratory forces developed by the exciter drive means in the direction of movement are positively transmitted through the supporting means to the trough and the vibratory forces developed by the exciter drive means in a direction transverse to the direction of movement of material are absorbed by the flexing of said supporting means in said transverse direction and by the flexible mounting of the second exciter drive means.

2. The vibratory conveyor as defined in claim 1 wherein each said supporting means comprises a platform upon which one of said exciter drive means is mounted and strap means connecting said platform to said trough, said strap means lying parallel to the straight line path for transmitting the vibratory force to the trough, said strap means flexing in a direction transverse to said straight line path for absorbing vibratory forces transverse to the straight line path.

3. The vibratory conveyor as defined in claim 1 whereby means are provided for selectively operating the first-named exciter drive means and the second exciter drive means to advance the material on the trough selectively in either the first-named direction or in a second opposite direction along the trough.

4. The vibratory conveyor as defined in claim 3 wherein each said strap has a substantially planar configuration and is flexible transversely to the plane within which it resides in response to vibratory forces imparted by said exciter drive means for absorbing the forces transverse to the straight line path.

5. In a vibratory conveyor having a resiliently supported trough, the improvement comprising: a first exciter drive means for imparting vibratory forces to said trough along a straight line path, a second exciter drive means for imparting vibratory forces to said trough along a straight line path that is opposite to the straight line path of said first exciter drive means; means for supporting each of said exciter drive means from said trough along axes that intersect at an angle of 90, to each other, each of said supporting means mounting said exciter drive means substantially rigidly in a direction parallel with said straight line path and substantially flexibly in a direction transverse to said straight line path;; said vibratory forces developed by each exciter drive means in the direction of movement are positively transmitted through the supporting means to the trough and the vibratory forces developed by the exciter drive means in a direction transverse to the straight line path are absorbed and isolated by the flexing of said supporting means in said transverse direction.

6. The vibratory conveyor as defined in claim 5 wherein each said supporting means comprises a platform upon which one of said exciter drive means is mounted and strap means connecting said platform to said trough, said strap means lying parallel to the straight line path for transmitting the vibratory forces to the trough, said strap means flexing in a direction transverse to said straight line path for absorbing and isolating the vibratory forces transverse to the straight line path.

7. The vibratory conveyor as defined in claim 5 wherein said supporting means comprises a pivotable connection between the exciter means and the trough.

8. The vibratory conveyor as defined in claim 7 wherein said supporting means comprises a coil spring connecting between the trough and the exciter means.

9. The vibratory conveyor as defined in claim 7 wherein said pivotable connection includes said trough and each said exciter means having a pair of spaced ears, said ears on each exciter means and on the trough positioned in overlapping relationship with each other and a pin extends through the overlapped ears on the exciter means and the trough to maintain the same in pivoting operative relationship.

1 0. In a vibratory conveyor having a trough receiving and conveying material from one end thereof to the other, a pair of exciter means, and means for connecting said pair of exciter means to said trough for selectively imparting vibratory motion to said trough in one of two directions. said connecting means comprising:: a platform for each exciter means, means for mounting said pair of exciter means on said pair of platforms, a mount mounted on said trough and having a pair of planar surfaces extending transverse to the longitudinal axis of the trough and being angularly disposed with respect to the longitudinal extent of said trough, said planar surfaces being at right angles to each other, plate means for supporting one of said platforms and one of said exciter means on each planar surface of said mount, said plate means being rigid in a plane transverse to the planar surface of said mount for transmitting vibratory forces from the exciter means to the trough; and said plate means being flexible in a plane parallel to the planar surface of said mount for absorbing vibratory forces that are generated by the exciter member in a direction transverse to the plate means.

11. The vibratory conveyor as defined in claim 10 wherein each said plate means comprises strap members connecting the associated platform to the planar surface of the mount, said strap members lying perpendicular to the planar surface of the mount for transmitting the vibratory force to the trough, said strap members flexing in a direction parallel to said planar surface of the mount for absorbing vibratory forces transverse to the strap members.

1 2. A vibratory conveyor substantially as described herein with reference to Figures 1 and 2 or figures 3 and 4 of the accompanying drawings.