Field of invention

This invention relates to an apparatus or machine which removes husks (shells) from nuts such as Cashew or any other nut, without damaging the nut

General introduction

This invention is an apparatus which is capable of picking up a single nut from a heap of nuts, aligning it properly and removing the husk of it without harming the nut inside.

Background art

Nut shelling machines de-shell various types and sizes of nuts are well known in the art. These nut shelling apparatus can be simple table models, which can be operated manually or by an electrical or battery power driven motor, to commercial models used in high volume production. In each instance, the problem arises as to the amount of pressure necessary to crack the shell, while leaving the nut undamaged.

The other problem is that nuts come in varying sizes. The cracking device or mechanism must accommodate a variety of shapes and sizes of nuts. The accommodation to the adjustment must be able to avoid over cracking the nut or under cracking the nut. Most nut shelling machines use different devices, such as a levers, sharp objects or some type of device to crack the nut. The use of sharp objects such as these can result in pieces of the shell and nuts remaining in the collector or container.

In view of the above, the present invention is to provide a de-shelling machine that is easy to use, provides reliability in de-shelling nuts of various sizes and provides minimal damage to the nut DESCRIPTION Background of the invention

Cashew nut is an edible nut popular all over the world. It is being consumed directly as a nut or it is widely used as an ingredient in a variety of recipes. The cashew nut is covered with a robust shell which needs to be removed prior to consumption. The removal process is not easy and it is time consuming because of the hardness of the shell and the sap contaminated within the shell. The hardness of the shell makes it uneasy to remove the shell while the Sap tends to cause infections and wounds when it comes to contact with the skin. However, the consumers prefer Cashew nut shell removed without any harm done to the nut. Since the nut is highly susceptible to split in to two halves while removing the shell, it is being done manually with an extra care. These reasons make the task of removing shells from cashew nuts difficult and time consuming.

Removing the shell is the most important task of Cashew processing industry. Being difficult and inefficient, this process makes the industry retard from growing and being popular. Developing a method to de shell Cashew nuts can directly help the growth of Cashew nut processing industry.

Therefore, this invention aimed was aimed to develop a machine capable of removing shells from cashew nuts effectively and efficiently. The performance of the machine concept was overwhelming. This made the inventor to test same concept of other nuts covered with robust shells such as Almond. Those experiments were equally successful.

The machine claimed in this invention is designed to remove any nut (Such as but not limited to Cashew) from its shell or husk. "Cashew nut "is used in this document for the purpose of illustrating and explaining. But it should be well noted that this machine is designed and can be used to removing shells from a number of varieties of different nuts.

The invention can be summarized under two versions. In one, Nuts are picked one by one and pushed vertically along a vertical grove. In the second method, the nuts are pushed horizontally along a horizontal groove. The first version is summarized blow. In this method the de-shelling process (removal of husk) of cashew nuts is done in three main steps. First, a single nut gets picked up from a heap of nuts by a device named as "Nut Picker". Then the nut is directed to the feeding trumpet where it is being rotated in to required vertical position and aligns with a vertical groove. Finally the nut gets pushed down the groove by means of a device named as the nut pusher. A pair of cutters mounted in the latter part of the groove makes two slits in each side of the shell while the nut passes them. Finally, the nut passes a couple of contoured plates. They are aligned with the cutters so that the plates go through the slit, making the shell to rip apart and release the nut without doing any harm to it.

The operation of the machine is started by loading a suitable amount of unprocessed Cashew nuts in to the loading trays devised in the machine. Once the machine is started, the device named as "Nut picker" which is mounted right above the feeding tray can pick up individual nuts and release them one by one in to the next operation. This is necessary because the next operation can handle only one nut at a time. The nut picker rotates in a vertical plane. The bottom part of the device comprises with a specially designed spoon. Therefore when it rotates, nuts are getting picked up by the spoon. To hold the nut whiles the device rotating and release it at desired location, a gripper is used. The gripper pushes the nut against the spoon when the holding grip is needed. This pushing action is generated by the menace of a coil spring. When the nut picker passes a few degrees after the apex of its rotation, the nut should be released. This is being done by releasing the gripper. These actions are being controlled by the roller cam mechanism. The roller follower is mounted to the gripper. And the cam which has a shape of semi circle is mounted to mesh with the follower. Its centre coincides with the axis of rotation of the nut picker. The cam has high and low levels. When ever gripper should be released, which means when the cam roller should move up, the cam uses its high dwell. So, by rotating the cam appropriately, the release and gripping action of the nut picker can be adjusted.

Once a single nut is being picked up, the Nut picker releases it in to the feeding trumpet. The shape of the feeding trumpet rotates the cashew nut in to the required position. Another device known as nut pusher is also used in this operation.

Beneath the feeding trumpet is the feeding grove. The feeding groove is narrow and only one cashew nut can pass through it at a time. Also, the nut can only pass through it when it is in vertical position. Nut pusher runs through the grove and is in a reciprocating movement. Nut pusher comprises with two parts. They are solid pusher (which is mounted on top part of the slider) and swinging pusher (mounted in the bottom part of the slider). Solid pusher moves through feeding trumpet and half way of the groove. When it moves down, it pushes the nut along with it making the nut to rotate and slide in to the groove vertically. Since the solid pusher takes the nut only half way of the grove, the nut comes to a stationary during the next upward stroke. Spring tensioned feeding groove makes sure that the nut is held firmly. And during the upward stroke, the swinging pusher rises. Its pushing plates are devised to lean inwards when hit by an obstacle. So, when they move up, the nut acts as an obstacle making the pushing plates to lean in; thus the position of the nut remains the same. But there is no leaning action takes place during the downward stroke. So during down stroke, the pushing plate pushes the nut all the way down the groove.

A couple of cutters are mounted at the latter part of the groove. When the nut passes through the cutters, two deep slits are made on the shell. A pair of contoured plates is placed right beneath the cutters. The contour is such that; the two plates are joined at the start ant their gap increases gradually as moving down. Also, the plate edges raise only few millimetres from the grove surface. When the nut moves down, the contoured plates went in to the slit made by cutters. When the nut moves down further more, the shell will be ripped open and nut falls out from the shell.

In the second version in this invention, individually picked up nuts are released on to a slide which makes them to roll in to slot. From there, a horizontally operating nut pusher will push the nut along a feeding groove which is placed horizontally. The same parts used in version one is used in this version. The difference is the feeding is done horizontally. The advantage of version two over version one is that the shells can be separated easily from the nut. Detailed description of preferred embodiments

Figure A illustrates two views of the nut picker assembly.

Figure B shows the back elevation of nut picker assembly. Cam (1) is comprised with circular arc segments of two radii. Their centre point coincides with the centre of rotation of the shaft (7) which the assembly is mounted on to. The cam is rigidly fixed on to the machine frame. The roller follower (3) is rigidly fixed to the gripper (4). The roller follower assembly can freely slide on nut picker frame (8). Spring (2) goes through the spring barrel (6) which is rigidly fixed on to the roller follower assembly and pushes against the nut picker frame (8). As a result of the spring tension generated by this, the roller follower tends to push against the minimum radius of the am. This makes the gripper to keep a clearance between the Spoon (5) and the gripper. The full assembly except the cam rotate when the shaft rotates. And the shaft rotates in the direction shown by the arrow; i.e. counter clock wise direction in this drawing. When the roller follower exceeds the limit of the cam, it brings the gripper in to contact with spoon due to spring tension.

Figure C is an image sequence illustrates the nut picking action. It should be noted that the nut picker is mounted just above the loading in tray (not shown) so that the device continuously passing through a heap of nuts while rotating. The picking action begins with climbing of a nut on to the spoon. This is shown in figure 3.1 and this happens while the nut picker rotates through the heap of nuts. It should be noted that the cam roller is still on the minimum radius of the cam thus the gripper provides an adequate room between it self and spoon. When the nut picker assembly keeps on rotating, the roller follower exceeds the cam. This would gradually let the roller follower assembly to move outwards from the centre point. This is shown in figure 3.2. This action makes the gripper to extend and grip the nut by pushing it against the spoon. Figure 3.3 shows the end of the picking cycle. When it comes to this point, the roller follower comes in to contact with the cam surface pushing the gripper inwards. This would loosen the grip on the nut and let it fall out from the spoon, in to the feeding trumpet. Figure D shows the complete nut pushing mechanism. Power from the electrical motor is directly transmitted to the fly wheel (1) via a belt drive and a pinion wheel. It cranks the rocker arm (2) which makes the slider link slides up and down simultaneously. Due to this movement, the nut pusher base (3) sets in to reciprocating motion. To accommodate the nut pushing elements motion and to make sure the nut is being held firmly while its shell being removed, the feeding trumpet is made in three sections. They are rigid feeding trumpet (not marked), Split feeding trumpet (4) and split feeding grove (4). The rigid feeding trumpet is mounted to machine frame. The other trumpet is hung on the machine frame and is free to rotate about it. The split groove is mounted on to the Split groove actuator (6). Both of them are tensioned by the springs (5) and (6) to keep them pushed against their respective rigid members, solid feeding trumpet and solid feeding groove. This would ensure a firm hold of the positioned nut. Also, this makes the feeding trumpet to adjust according to different sizes of cashew nuts. The action of springs is enhanced by rigidly fixing the solid feeding trumpet (7) on to the machine frame. It should be noted that one half of the feeding groove is embedded on to the solid feeding trumpet (this is referred to as the solid feeding groove). The split feeding trumpet is suspended on a shaft (10) making it free to rotate around the shaft. And due to the action of the coil spring, it is always kept pushed against the solid feeding trumpet. The Split feeding groove (11) is mounted on to Split groove actuator (6) which is suspended on a rail (not shown). Therefore, it is free to move towards solid feeding trumpet and return. This also is devised to be kept pushed against the feeding groove of solid feeding trumpet by means of two coil springs. Further more, the cutter blades (8) and the contoured plates (9) are also mounted middle and bottom areas of the feeding groove, as shown in figure.

In figure E, more detailed view of nut pushing mechanism is shown. In the front elevation, a sectional drawing of the feeding trumpet is shown. The preferred alignment for cashew nut (1) also is shown in this drawing. In end elevation, the split feeding trumpet and split feeding groove are omitted to illustrate the elements of nut pushing mechanism. The machine is designed with two Feeding trumpets. But in this drawing, left trumpet is omitted. Figure F shows the important components of the feeding mechanism and the nut pushing assembly.

Two cutter blades (5) are fixed in half way of the split feeding groove and the feeding groove of the rigid feeding trumpet (1). The Nut pusher comprises with 2 main parts. They are Solid pusher (7) and the Swinging (8) pusher. The moveable pusher is mounted on a shaft and being held out by the tension of a spring (3). Therefore, when hit by an obstacle during its upward movement, the moveable pusher can lean inwards. But it should be noted that this is not free move during the down ward stroke.

Figure G illustrates how a cashew nut is being aligned and pushed down the groove. When a Cashew nut is being dropped in to the feeding trumped by the nut picker, the nut lies in a position similar to the one which is shown in image 1. The motion of the nut pusher starts from the topmost position of the slider. That position is showed in image 1 and the nut pusher starts its down stroke. When it comes to the position shown in image 2, the Solid pusher hits the Cashew nut, rotates it and secures it in the notch made in nut pusher and pushes the nut halfway down the groove. This would bring the system to a position similar to image 3. With this, the upward motion of the nut pusher starts. While moving up, the nut pusher comes to the state shown in figure 4.Previously fed cashew nut is now held firmly in between two feeding grooves by the spring tension of the feeding groove actuators. The moveable nut pusher keeps on rising and hits the nut. Moving further, the moveable nut pusher swings inwards while passing the cashew nut and returns back to its original position once it passes the nut. This is shown in image 5. Then, as shown in image 6; the movable nut pusher pushes the nut all the way down, passing the cutter blades and contoured plates. This removes the shell from the nut.

Figure H is an isometric rendering of a contoured plate. There ore two such plates used when removing Nut from its shell. The two contoured plates should be positioned opposite to each other as illustrated in Figure J. Process of removing Nut from its shell is illustrated in figure I and the same is explained in the paragraph below. In figure I, the removal of shell is illustrated in 5 steps. Front elevation is provided in this drawing and one of the two contoured plates is not shown in this view. (Please refer drawing J to visualize the orientation of the contoured plates.). It should be noted that the contoured plates rises only a few millimetres above the surface of the feeding groove. When the nut is being pushed down by the Nut pushers, two slits will be made on either side of the nut. Moving down further, these slits enter in to the vertex of the contoured plates. The contour of the plates makes the shell to rip apart gradually, thus the shell is removed and the nut is fallen out.

In figure J, the above steps are illustrated with a computer generated phantom drawing. It should be noted that there are two pairs of contoured plates. One pair has drawn transparent in order to illustrate the steps of husk removing process.

Figure K Shows the second version of this invention. Here, nuts are directed to the main slide (1) by a nut picker as explained above. The nut is rolled down the main slide and enters in to the slot made at the end of the slider. One side of the slot opens to the feeding groove (6) fixed horizontally. The opening between the slot in the slide and the feeding groove is shaped in such a way that the nut automatically turns in to required position while passing in to the feeding groove. The nut pusher (8) is set to work horizontally. Here also, the feeding groove (6), cutters (5) and the contoured plates (4) are available. There operation as well as the operation of nut pusher assembly (only the swinging pusher is shown in the drawing) the same as in version one. Thereby, when the nut reaches the end of the feeding grove, the shell is removed and the two halves of the shell is directed away along she waste slides and only the nut is released on to the tray.

Brief description of drawings

Figure A

Figure A shows two views of the nut picker assembly.

Figure B

Figure 2 shows the main parts of the nut picker assembly.

Figure C

The sequence of figures shows the nut picking action in three steps.

Figure D

This diagram shows the complete view of the slider crank mechanism, nut pushing mechanism and the feeding trumpet. An enlarged cross sectional drawing of the feeding trumpet is also included.

Figure E

In this diagram, two detailed views of the nut pushing mechanism are shown. Sectional view of the feeding trumpet and grove are shown in the front elevation and only the rigid part of the trumpet is shown in the end elevation. Second trumpet is omitted in this view for clarity.

Figure F

Close-up views of front and end elevations of the nut pushing mechanism are shown in this drawing.

Figure G

Image sequence shown in this drawing illustrates how a cashew nut in feeding trumpet gets properly aligned with the cutters and how it is being pushed down the feeding groove.

Figure H

An isometric rendering of a set of contoured plates

Figure I

A sequential illustration of the shell removal performed when the silted Cashew nut passes the set of contoured plates.

Figure J

A computer generated rendering of the sequence of cashew shell removal taking place while the nut passes the contoured plates is shown in this illustration.

Figure K

Is a wire frame model of the version 2 of the same invention; where, the nut is being fed horizontally.