GB2071999A - Brussels sprout stripper - Google Patents

Abstract

Apparatus for stripping attached parts, such as Brussels sprouts, from a stalk includes a rotary stripper head (2) with pivoted lever arms (6) carrying respective knives (7). When the stripper head (2) is rotated, the knives (7) are moved towards the stalk, against the action of biassing springs, by the effect of centrifugal forces on movable masses (8) associated with the lever arms (6). The knives (7) project from the leading ends of the lever arms (6) so that the cutting edges of the knives (7) will be closer to the stalk than the trailing edges as the lever arms (6) move towards the stalk, thereby permitting cleaner stripping than is possible with known apparatus in which the knives are carried at the trailing ends of the arms. <IMAGE>

Description

SPECIFICATION Apparatus for stripping attached parts from vegetable stalks l This invention relates to apparatus for stripping attached parts from vegetable stalks. The invention has particular, but not exclusive, application to the stripping of sprouts from the stalks of Brussels sprout plants. Such apparatus would normally be used in conjuction with machines for harvesting the plants.

In known apparatus for stripping Brussel sprout plants, as described, for example, in GB 958 114, GB 1 561 998 or US 4 151 847, the individual stalks are gripped and drawn through a individual stalks are ped with a rotary cutter, the stalks being fed along the axis of rotation of the cutter. The cutter consists of a number of lever arms pivotally mounted upon a rotary carrier for rotation about axes parallel to the axis of rotation of the carrier, each lever arm carrying a stripping knife which is moved inwardly towards the surface of a stalk to be stripped as the carrier rotates.The inward movement of the stripping knives can be effected by centrifugal forces acting upon masses associated with the individual knife carrying lever arms, by resilient means acting on the lever arms, or by cam means associated with a gripping device which grips the end of each indi vidual stalk to draw it through the rotary carrier.

In known apparatus for stripping Brussels sprouts and similar vegetable stalks, the lever arms which carry the stripping knives project from their pivot axes in a direction having a circumferential compo nent opposite to the direction of rotation of the carrier, so that the knives are carried at the trailing ends of the lever arms. The stripping knives at the free ends of the lever arms project axially and radially inwardly with respect to the axis of rotation of the carrier, the knives having cutting edges which extend partly circumferential ly with respect to the said axis of rotation.As the lever arms carrying the stripping knives move inwardly towards a stalkto be stripped, these cutting edges of the stripping knives become inclined to the circumferential direction, with the result that the leading edges of the knives, which are also cutting edges, are spaced some distance from the surface of the stalk to be stripped when the trailing edges of the knives are in contact with, or gouging the surface of, the stalk. As a result, the stalk is not stripped cleanly, and a substantial portion of the sprout or other part to be stripped can be left on the stalk, particularly at the narrower end of the stalk. This is especially undesirable in appar atus intended for the stripping of Brussels sprouts for the fresh vegetable market.

An object of the present invention is to provide an improved apparatusforthe stripping of attached parts from vegetable stalks, avoiding the disadvan tage referred to above.

Accordingly the present invention provides appar atus for stripping attached parts from a vegetable stalk, comprising stalk gripper means for gripping a stalk to be stripped and drawing it through a cutter station provided with a rotary carrier on which a number of lever arms are pivotally mounted about axes parallel to the axis of rotation of the carrier, the lever arms carrying respective stripping knives and being urged radially inwardly in operation of the apparatus so that the knives approach the surface of the stalk, and brake means selectively operable to brake the rotation of the carrier, in which the lever arms project from the pivot axes in the direction of rotation of the carrier, and the knives are mounted so as to lead the respective pivot axes during rotation, whereby cutting edges of the knives approach closer to the stalk than trailing edges thereof.

The lever arms may be mounted upon respective spindles which are interconnected by an endless chain or belt to ensure that the lever arms pivot in unison. The brake means may comprise any suitable arrangement, but preferably comprise a band brake operable manually, or by a foot pedal, into frictional engagement with the periphery of the carrier.

In some embodiments, the stripper knives are carried at the free leading ends of the lever arms, and may project in directions having both a radially inward and an axial component towards the direction from which the stalks are fed. Preferably, each knife has a cutting edge with a part which extends in a generally circumferential direction with respect to the axis of rotation of the carrier, the leading end of said cuting edge being further from the pivot axis of the respective lever arm than the trailing end of said edge.With this arrangement the leading edge of each knife will be ci oser to the surface of the stalk to be stripped than the trailing edge of the knife, as the lever arm moves inwards towards the stalk, thereby permitting much cleaner stripping of the stalk than is possible with an apparatus having stripping knives mounted at the trailing ends of lever arms where the trailing edge of the knife is closer to the stalk than the cutting edge.

In one embodiment of the invention, means, for example, biassing springs, act directly or indirectly on the lever arms to urge the latter radially outwardly when the carrier is braked, and movable masses are associated with the lever arms so that, upon rotation of the carrier, the effect of centrifugal forces on the masses overcome the action of said means and urge the lever arms radially inwardly.

The brake means may be arranged to act directly upon the centrifugal masses so that braking of the carrier will be accompanied by radially inward movement of the centrifugal masses, causing the lever arms to move outwardly and "open" the cutting knives to allow the insertion of a stalk to be stripped. In this latter case, the biassing springs may be omitted or arranged to supplement the centrifugal forces urging the lever arms, and thus the knives, radially inwardly towards the stalk upon rotation of the carrier. If the springs are arranged to urge the lever arms inwardly, the centrifugal masses may be reduced so that the lever arms assume the form of bellcrank levers, with a first arm projecting inwardly from its pivot axis in the direction of rotation and a second arm projecting peripherally of the carrier in the opposite direction and engageable by the brake means.

In a second embodiment of the invention, the carrier includes a member which is coaxial with the carrier and is arranged to rotate relative to the latter upon initial engagement of the brake means, each lever arm being connected to the coaxial member so that the relative movement causes the arms to move radially outwardly.

In one example of this second embodiment, the lever arms extend along respective chords of a circle described by the pivot axes of the arms during rotation of the carrier, and the coaxial member comprises a brake ring which is arranged peripherally of the carrier on the opposite face of the latter from the lever arms and is engageable directly by the brake means, the brake ring having pins which project through respective arcuate apertures in the carrier and engage respective lugs at the opposite ends of the lever arms from the pivot axes, the extent of the arcuate apertures determining the amount of relative movement between the carrier and the pins of the brake ring and thereby the extent of radial movement of the arms.The lever arms may be urged inwardly during rotation by centrifugal forces as described above, but it is envisaged that respective biassing springs would be used more conveniently.

Although the construction of this embodiment does not allow the knives to be carried at the leading ends of the lever arms, they are neverthelss in advance of the pivot axes of the arms during rotation, and the cutting edges of the knives are still moved closer to the stalk than the trailing edges when the lever arms move inward.

With the same objective of improving the precision with which the stripping knives cut the attached parts from the stalk, respective spacer means may be associated with the knives to ride on the suface of the stalk to be stripped and predetermine the cutting positions of said knives. The spacer means may comprise respective elements carried by the lever arms adjacent the respective knives, and these elements are preferably adjustable to allow precise regulation of the cutting position of each knife, according to the type of vegetable stalk being stripped and the type of stripping cut required. In other examples, the spacer means simply comprise a heel which is ground on the radially inner face of each knife to ride on the surface of the stalk and determine the cutting position of the knife. In this latter instance, the cutting position would not be adjustable.

The stalk gripper means may be of any suitable type, but preferably comprise two serrated gripper rolls which are driven through respective universal drive transmissions from a common drive motor.

Endless gripper belts may be wound around the respective gripper rolls to convey the gripped stalks away from the cutter station.

The invention will be further described, by way of example only, with reference to the accompanying purely diarammatic drawings, in which: Figure 1 is a schematic side elevational view of an apparatus for stripping Brussel sprout stalks according to one embodiment of the invention; Figure 2 is a partly sectioned end view in the direction of arrow II in Figure 1, of part of the apparatus shown in Figure 1; Figure 3 is a perspective view of one of the knife support assemblies used in the apparatus illustrated in Figures 1 and 2, and Figure 4 is a view similarto Figure 2 of a part of an apparatus according to a second embodiment of the invention.

The same reference numerals are used throughout the drawings for similar or corresponding component parts.

The illustrated apparatus is intended for the stripping of Brussels sprouts from the stalks of Brussel sprout plants. The apparatus has a vertical frame 1 which supports a stripper head 2. The stripper head 2 includes an annular carrier 3 which is connected through a belt drive (not shown) to an electrical or hydraulic drive motor (not shown) by means of which the carrier 3 is driven in the circumferential direction R (Figure 3).

As shown in Figures 2 and 3, the rotary carrier 3 carries a number of, in this example, four, pivoted knife supports 4 pivotally supported on the carrier 3 on respective spindles 5 arranged at equal circumferential intervals around the carrier 3. The axes of the spindles 5 are parallel to the axis of the annular carrier 3. Each knife support 4 comprises a lever arm 6 projecting towards the inside of the annular carrier 3 and in the direction of rotation R of the carrer 3 from the respective spindle 5. Each lever arm 6 carries at its free leading end a respective stripping knife 7 which, as shown in Figure 1, projects forwardly from the arm 6 in a direction opposite to the axial feed direction (arrow li) of the stalks to be stripped.Each knife 7 is releasable from its supporting lever arm 6 to facilitate replacement of worn knives 7, as illustrated in Figure 3.

The lengths of the lever arms 6 are such that the respective stripping knives 7 move in a circular arcuate path which intersects the axis of the annular carrier 3 upon anguiar movement of the lever arms 6 about their spindles 5.

On the opposite side of the carrier 3 from the lever arm 6 each spindle 5 carries an arcuate mass 8 extending generally circumferentially from the spindle 5, in a direction opposite to the direction of peripheral movement R of the rotary carrier 3.

The knife-carrying lever arms 6 are fixed to the respective spindles 5 by means of respective taper lugs aiid grub screws 9 (Figure 3). By slackening the screws 9, the lever arms 6 can conveniently be removed for adjustment of their angular position on the spindles 5, or for replacement when arms of different length are to be fitted.

The masses 8 are located in a circumferentially extending channel in the rotary carrier 3, so that when retracted radially inwardly, as shown in broken outline in Figure 3, the arms 8 form segements of an annulus. For convenience of illustration the masses 8 are visible in Figure 2, the carrier 3 being shown in ghost outline.

Two serrated gripper rolls 10, 11 are arranged on the downstream side of the stripper head 2 with their axes parallel to each other in a plane perpendicular to the axis of rotation of the carrier 3, the nip between the two rolls 10,11 being aligned with the axis of the carrier 3. Both gripper rolls 10,11 are driven from a common gearbox (not shown) in a direction of rotation whereby the teeth of the rolls which define the nip move away from the stripper head 2, as illustrated diagrammatically in Figure 1.

Respective endless gripper belts 14, may be associated with the respective gripper rolls 10, 11, as shown in Figure 1 forthe purpose of conveying stripped stalks away from the stripper head 2.

Conveniently, the same motor may be arranged to drive the transmission gearboxforthe gripper rolls 10, 11 and the rotary carrier 3 of the stripper head 2.

Respective sprockets (not shown) are fixed to each of the spindles 5, the sprockets being interconnected by endless sprocket chain 17, shown in dashed outline, which ensures that the knife supports 4 alawys move in unison.

Each of the knife-supports 4 is spring-loaded in by a biassing spring (not shown) which acts on the lever arm 6 or its spindle 5 to urge the associated knife 7 outwardly away from the aperture of the carrier 3 so that, when the latter is stationary, the knives 7 are urged radially outwardly on their arms 6 to a position of maximum opening ready to receive a sprout stalk S to be stripped.

A braking element in the form of a band brake 18, shown diagramrnatically in chain-dotted outline in Figure 2, surrounds the circumferential channel in the rotary carrier 3. The brake 18 is operable manually, or by a foot pedal 18A, into frictional engagement with the carrier 3 and/orthe masses 8 of the knife supports 4, to effect braking of the rotary carrier 3, while simultaneously resisting the outward pivotal movement of the masses 8 which is caused by the centrifugal forces during rotation and is opposed by the biassing springs.

In operation of the apparatus individual cut stalks of Brussel sprout plants, harvested by hand or by machine, are fed successively to the stripper head 2, the stalks being offered up to the stripper head 2 with their cut ends leading in a generally axial direction coinciding with the axis of rotation of the carrier 3. Initially the carrier 3 is braked, so that the knives 7 are urged into their fully open position by the biassing springs and by the action of the brake 18 on the masses 8, which causes outward pivotal movement of the lever arm 6. The stalk end is engaged with the nip of the gripper rolls 10, 11 and the brake 18 is then released. The carrier 3 commences rotation, and the centrifugal forces acting upon the masses 8 overcomes the biassing springs acting on the supports 4 to cause outward pivoting movement of the masses 8 as shown in full lines in Figure 2.This in turn causes the lever arms 6 to move inwardly towards the axis of the carrier 3, moving the respective stripping knives 7 towards each other until they meet the stalk S to be stripped.

The rotation imparted to the knives 7 by the rotary carrier 3, as the stalk S is drawn through the cutter head 2 by the rolls 10, 11, causes the knives 7 to move circumferentially around the stalk S stripping the sprouts therefrom.

The sprouts severed from the stalk are collected in a convenient hopper or chute on the upstream side of the stripper head 2 while the stripped stalks, after passing through the nip of the gripper rolls 10,11 fall into a hopper 19.

It will be noted that each stripping knife 7 (Figure 3) has a generally axially and radially inclined cutting edge 20 at the leading end of the respective lever arm 6, and a generally circumferentially extending cutting edge 21 at the free end of the knife 7. As the lever arm 6 moves radially inwardly towards the stalk S, under the action of the centrifugal force acting on the associated mass 8 due to the rotation R of the carrier 3, the cutting edges 20, 21 will move closer to the stalk S than the trailing edge 22 of the knife 7. This means that a close trimming of the stalk S is possible - closer, in fact, than is possible if the stripping knives 7 were mounted at the trailing ends of the lever arm 6.In this latter case, the trailing edges of the respective knives would come into contact with the stalk to be stripped before the cutting edges, and this would limit the approach of the cutting edges towards the stalk. The illustrated arrangement, in which the leading and cutting edge 20 of the knife 7 is further from the pivot axis of the supporting arm 6 than the trailing edge 22, therefore permits greater precision and control in the stripping of the individual sprouts from the stalk S.

In order to predetermine the depth of cut made by each stripping knife 7 the individual lever arms 6 carrying the knives 7 may each be equipped with a spacer elment 23 which, as shown diagrammatically in Figure 3, is carried behind the knife 7 with respect to the direction of rotation. The illustrated spacer element 23 consists of a probe carrying at its free end a foot 24 which is shaped to come into contact with the surface of a stripped stalk S. The probe 23 is adjustable in the lever arm 6 by means of a screw-threaded adjustment and associated lock nut 25.By presetting the depth of the probe 23, the height of the cut made by the associated cutting knife 7 may be predetermined, so that sprouts can be severed from the stalk S either close to the stalk S to leave a butt, as is required when preparing sprouts for the fresh vegetable market, or at a predetermined distance from the surface of the stalk S to reduce the butt, as is preferable when trimming sprouts for the pre-packed or frozen food market.

The spacer elements 23 associated with the lever arms 6 may take any convenient form, and in some cases may even be located in front of the associated stripping knives with respect to the direction of rotation of the knife assembly. In a simple alernative arrangement (not shown), the radially inner surface of the knife 7 is ground to form a heel which rides on the surface of the stalk Sand maintains the cutting edges 20, 21 of the knife 7 in a fixed cutting position.

Figure 4 illustrates an alternative embodiment of the stripper head 2, which uses so-called "contrarotation" to effect automatic opening of the lever arms 6 against the action of respective biassing springs 5A, when the rotation of the carrier 3 is braked. While the lever arms 6 are pivoted to the carrier 3 in the manner described above, the knives 7 are mounted intermediate the ends of the arms 6, since the lever arms 6 extend along respective chords with respect to the annular carrier 3 and the leading ends of the arms 6 are provided with respective lugs 26. Despite this arrangement, the knives 7 are moved closer to the stalk than the trailing edges upon inward movement of the lever arms 6, as with the previously-described embodiment.

Each lug 26 projects from its respective lever arm 6 in the direction of rotation R of the carrier 3, and has an elongate slot 27 which is parallel to the lever arm 6. The slots 27 are engaged with respective pins 28 which project from a brake ring 29 arranged circumferentially on the opposite side of the carrier 3 from the lever arms 6, the pins 28 passing through respective arcuate apertures 30 in the carrier 3 which are concentric with the axis of the latter.

The brake ring 29 is rotated with the carrier 3 in the direction R and is arranged to be engaged directly by the band brake (not shown) upon braking, so that the carrier 3 can over-run the brake ring 29 by an amount corresponding to the extent of the arcuate apertures 30. The resulting relative movement R' between the pins 28 and the carrier 3, the so-called "contra rotation", causes the lever arms 6 to rotate outwardly to the position 6A (as shown in broken outline for one arm only) and open the knives 7 ready to receive a stalk for stripping. The slots 27 in the lugs 26 accommodate the radial component of this outward movement. When the brake is released, the springs 5A urge the arms 6 inwardly to carry the knives 7 towards the stalk.

Claims (12)

1. Apparatus for stripping attached parts from a vegetable stalk, comprising stalk gripper means for gripping a stalk to be stripped and drawing it through a cutter station provided with a rotary carrier on which a number of lever arms are pivotally mounted about axes parallel to the axis of rotation of the carrier, the lever arms carrying respective stripping knives and being urged radially inwardly in operation of the apparatus so that the knives approach the surface of the stalk, and brake means selectively operable to brake the rotation of the carrier, in which the lever arm project from the pivot axes in the direction of rotation of the carrier, and the knives are mounted so as to lead the respective pivot axes during rotation, whereby cutting edges of the knives approach closer to the stalk than trailing edges thereof.

2. Apparatus according to Claim 1, in which each knife has a cutting edge with a part which extends in a generally circumferential direction relative to the axis of rotation of the carrier, the leading end of said cutting edge being further from the pivot axis of the respective lever arm than the trailing end of said edge.

3. Apparatus according to Claim 1 or Claim 2, in which means act directly or indirectly on the lever arms to urge the latter radially outwardly when the carrier is braked, and movable masses are associ ated with the lever arms so that, upon rotation of the carrier, the effect of centrifugal forces on the masses overcome the action of said means and urge the lever arms radially inwardly.

4. Apparatus according to Claim 3, in which the means acting on the lever arms comprise respective biassing springs.

5. Apparatus according to Claim 1, Claim 2 or Claim 3, in which the lever arms are mounted on respective spindles which are interconnected by an endless chain or belt to ensure that the lever arms pivot in unison.

6. Apparatus according to Claim 1, in which the brake means comprise a band brake operable manually, or by a foot pedal, into frictional engagement with the periphery of the carrier.

7. Apparatus according to Claim 3 and Claim 5, in which the movable masses are arranged peripherally of the carrier and project in the opposite direction to the direction of rotation of the carrier, the band brake being arranged to act directly on said masses during.

braking to move the masses radially inwardly and thereby move the lever arms radially outwardly.

8. Apparatus according to Claim 1, in which the .

carrier includes a member which is coaxial with the carrier and is arranged to rotate relative to the latter upon initial engagement of the brake means, each lever arm being connected to the coaxial member so that the relative movement causes the arms to move radially outwardly.

9. Apparatus according to Claim 8, in which the lever arms extend along respective chords of a circle described by the pivot axes of the arms during rotation of the carrier, and the coaxial member comprises a brake ring which is arranged peripherally of the carrier on the opposite face of the latter from the lever arms and is engageable directly by the brake means, the brake ring having pins which project through respective arcuate apertures in the carrier and engage respective lugs at the opposite ends of the lever arms from the pivot axes, the extent of the arcuate apertures determining the amount of relative movement between the carrier and the pins of the brake ring and thereby the extent of radial movement of the arms.

10. Apparatus according to any preceding claim, in which the knives project from the lever arms in directions having both a radially inward and an axial component towards the direction from which the stalks are fed.

11. Apparatus according to any preceding claim, in which respective spacer means are associated with the knives to ride on the surface of the stalk to be stripped and predetermine the.cutting positions of said knives.

12. Apparatus for stripping attached parts from a vegetable stalk, substantially as herein described with reference to, and as shown in, the accompanying drawings.