Technical Field of Invention

The present invention relates to the field of agricultural mechanics. Specifically, the invention relates to a cashew nuts shelling machine.

Background of Invention

The cashew nuts are one of the high value agricultural products in the world agricultural economy as well as in Vietnam. Post-harvest stages such as shelling, preservation and processing in order to reduce losses as well as maintain cashew nut quality are extremely important and necessary work, but also labour intensive and strenuous. In particular, the cashew nut shelling process is of great significance, directly affecting the product price. The shelling of cashew nuts should ensure that the shell is clean, reduce the rate of broken kernels, the rate of oil contamination,... and must have a high yield.

There are many methods to shell a cashew nut: a manual method using splitter, a semi-manual method using a manual cashew nut cutting table or a manual cashew nut separator, a method of separating a cashew nut by industrial nut separator.

For the manual and semi-manual methods, these methods requires the worker’s hand-to-foot coordination. Therefore, productivity depends on the ability of workers, the number of workers per shift. In addition, the kernel broken ratio is also higher than using the machine.

The cashew nuts shelling machine also called a cashew nut splitter is used to remove the shell and collect the cashew kernels on an industrial scale, without using labor for the shelling process. Depending on the model that the current cashew nut separators have different structures, but the basic structure includes: a machine frame, feeding unit, a cashew nut guide groove into the blade system, a cashew nut locator to erect the cashew nuts in a certain cutting direction and cutter to separate the shell. The operating principle of these machines is: the cashew nuts are poured into the feeding unit, from that, the cashew nuts are evenly distributed into the guide grooves, the scraper mechanism will push the cashew nuts along the guide groove towards the cutter to separate the shelling, on the guide groove is arranged with a scraper mechanism to evenly erect the cashew nuts in a definite direction (for example, vertically) so that the cutter will cut exactly into the shell to separate the shell from the kernel. The machine structure as described above has the disadvantage that: the cashew nut guide grooves are structured in the form of straight grooves, were arranged parallel to each other on a plane. Since the distance between the cutter and the depth of the guide groove remains constant during a cutting cycle so when the cashew nut comes into contact with the blade, the cutting path into the nut will be a straight line while the nut contour is curved. Therefore, the cutting path does not adhere to the nut contour. The quality of the finished nut will decrease because of the increased chance of breakage due to cutting too deep into the kernel or not separating the shell because of cutting too shallow. In addition, the current structure of cashew nuts shelling machines is also cumbersome because it mainly uses a chain drive mechanism. The large machine structure requires large workshop scale, not suitable for small and medium production scale.

Summary of Invention

The purpose of the present invention is to provide a cashew nuts shelling machine capable of producing a cutting path that closely adheres to the nut contour, ensuring an optimal depth of cut, thereby removing the shell and reducing the kernel broken ratio.

Another purpose of the present invention is to provide a cashew nuts shelling machine with a compact structure, suitable for a wide range of productions.

To achieve the purposes mentioned above, the present invention provides a cashew nuts shelling machine comprising: the machine frame is textured with bearings distributed opposite each other on both sides of wall of the machine to support the rotation shafts of the transmission mechanism; the transmission mechanism consists of the rotation shafts parallel to each other which are supported on the above-mentioned opposite bearings to drive the machine mechanisms, the rotation shafts of the transmission mechanism are driven by the motor through the gear transmissions; the feeding roller is made of a cylindrical structure, there are feeding holes on the surface of which the corresponding shape of each hole can hold a cashew nut, the shaft of the feeding roller is one of the rotation shafts of the transmission mechanism; the nut brush is made of a cylindrical structure, arranged above the feeding roller, the rotation shaft of the nut brush is parallel to the feeding roller shaft; the nut guide grooves are textured in the form of a curve along the groove length, these grooves are arranged close together along the length to form a curved surface, the nut guide grooves have a gap at the bottom of the groove, each nut guide groove is located respectively opposite a row of holes in the feeding roller and the feeding roller is directly above the groove inlet; the bar scrapers have at least an end mounted on a gear ring to form a hollow cylindrical frame, the scrapers are parallel to each other and uniformly distributed on the gear ring mentioned above so that when in motion, the upper scrapers are always at a position higher than the surface of the nut guide grooves, the aforesaid gear ring is driven by another rotating shaft parallel to the rotating shaft that drives the feeding roller; the nut pusher is arranged on another rotating shaft parallel and lower than the rotating shaft that drives the feeding roller, the nut pusher consists of identical toothed discs arranged consecutively along the rotation shaft, with each corresponding toothed disc opposite a row of holes in the feeding roller, the nut pusher is positioned below the nut guide grooves so that each the toothed disc is respectively opposite the below of one nut guide groove and the teeth can move in the groove; above each nut guide groove is arranged a locating box to erect the cashew nuts evenly in a certain direction before the nuts come into contact with the cutter, the locating box has a curved shape corresponding to the nut guide groove, is arranged parallel to the nut guide groove and a distance higher than the nut guide groove in accordance with the nut height; each blade holder is located corresponding to the nut guide groove and is arranged behind the locating box in the direction of nut movement, the blade holder is textured to hold the blade in a fixed position during the cashew nut shelling process and has a curvilinear shape corresponding to the nut guide groove.

In addition, the cashew nuts shelling machine of the present invention may include a number of distinct features, either separately or in combination, such as:

On the feeding roller shaft and the nut pusher rotation shaft with gears, these gears are engaged through an intermediate gear so that the feeding roller and the nut pusher to rotate in the same direction.

The gear ring with the scrapers engages directly with a gear on the motor drive shaft and the gear mounted on the nut pusher also engages directly with another gear on the motor drive shaft. This drive structure ensures that the scrapers and the nut pusher to rotate in the same direction.

The gear ring with the scrapers is indirectly engaged with a gear on the motor drive shaft through at least one intermediate gear and the gear mounted on the nut pusher also indirectly engages with another gear on the motor drive shaft through at least one other intermediate gear. The use of intermediate gears to change the gear ratio flexibly.

The scrapers are mounted on two opposing gear rings to increase the rigidity and stability of the mechanism during movement.

The locating box is grooved opposite the nut guide groove so that the nut guide groove and the locating box groove combines to hug the cashew nut contour to keep the cashew nut erected exactly in the desired direction. Brief Description of Drawings

The signs, advantages of the cashew nuts shelling machine according to the present invention will be described below based on the attached drawings, in which:

FIG. 1 is a schematic perspective showing the main parts of the cashew nuts shelling machine of the present invention.

FIG. 2 is a schematic perspective view in a different direction from FIG. 1 showing the main parts of the cashew nuts shelling machine according to the present invention.

FIG. 3 is the side view showing the transmission structure of the cashew nuts shelling machine according to the present invention.

FIG. 4 is the side view showing the transmission structure in another embodiment of the cashew nuts shelling machine of the present invention.

FIG. 5 is a schematic cross-sectional showing the working principle of the cashew nuts shelling machine according to the present invention.

FIG. 6 is a schematic perspective drawing showing the feeding roller of the cashew nuts shelling machine according to the present invention.

FIG. 7 is a schematic perspective drawing showing the nut guide grooves of the cashew nuts shelling machine according to the present invention.

FIG. 8 is a schematic perspective drawing showing the nut pusher mechanism of the cashew nuts shelling machine according to the invention.

FIG. 9a and FIG. 9b are a schematic perspective drawings showing the locating box of the cashew nuts shelling machine according to the present invention.

List of Reference Signs

Machine frame: 1

Intermediate gear: 11; 12

Motor: 2 Main transmission shaft: 20

Driving gear: 21 ; 22

Feeding roller: 3

Feeding hole: 31

Feeding roller shaft gear: 32

Brush: 4

Scraper: 5

Nut pusher: 6

Toothed disc: 61

Nut pusher shaft gear: 62

Guide groove: 7

Locating box: 8

Blade holder: 9

Detailed Description

Hereafter, the invention will be described in detail according to the available preferred embodiments based on the accompanying drawings. However, it should be understood that these embodiments are described for the purpose of providing examples only for a better understanding of the nature and advantages of the invention, without limiting the scope of the invention to the embodiments described herein.

As shown in FIGs. 1 to 5, the cashew nuts shelling machine consists of machine frame 1 to store machine parts, a motor 2 to drive working mechanisms, a transmission mechanism consists of rotating shafts and a gear transmission, a feeding roller 3 and a nut brush 4 to distribute cashew nuts evenly into the guide grooves 7, a scraper 5 and a nut pusher 6 to feed the nuts into the cutter, a locating box 8 to evenly erect the cashew nuts in a definite direction. The machine frame 1 is textured with bearings distributed opposite each other on both sides of wall of the machine to support the rotation shafts of the transmission mechanism. The machine mechanisms will be arranged on these rotating shafts.

The transmission mechanism consists of the rotation shafts parallel to each other that are supported on the aforementioned opposite bearings to drive the machine mechanisms. The rotation shafts of the transmission mechanism are driven by motor 2 through gear transmissions. The use of gear transmission instead of chain transmission on the conventional cashew nuts shelling machines will ensure the transmission reliability, a gear transmission also has fewer component parts and is simpler to maintain than chain transmissions. Specifically, as shown in FIG. 1 and 2, motor 2 will drive a main transmission shaft 20. On the main transmission shaft 20 mounte the driving gears 21, 22. In which, gear 21 drives the gear ring with the scrapers 5 and gear 22 drives the nut pusher 6.

According to a preferred embodiment of the invention, on feeding roller shaft 3 with gear 32 and the nut pusher rotation shaft 6 with gear 62, these gears are engaged through a intermediate gear 12. Such a texture ensures that feeding roller 3 and nut pusher 6 to rotate in the same direction.

According to a preferred embodiment of the present invention as shown in FIG. 3, gear 62 mounted on nut pusher 6 engages directly with gear 22 on main transmission shaft 20. Accordingly, the gear ring attached to the scrapers 5 will also directly engage with gear 21 on the main transmission shaft 20. This drive texture ensures that the scrapers 5 and the nut pusher 6 to rotate in the same direction. Direct- coupled texture ensures transmission reliability as well as ease of maintenance and reducing transmission size should be given priority in manufacturing.

According to another preferred embodiment as shown in FIG. 4, gear 62 mounted on nut pusher 6 indirectly engages with gear 22 on main transmission shaft 20 through at least one intermediate gear 11. Accordingly, the gear ring with the scrapers 5 will also indirectly engage with gear 21 on the main transmission shaft 20 through at least one other intermediate gear and still ensure to rotate in the same direction as the nut pusher 6. The use of intermediate gear to change the gear ratio flexibly.

As shown in FIG. 6, the feeding roller 3 is made of cylindrical structure. There are feeding holes 31 on the surface of which the corresponding shape of each hole can hold a cashew nut.

As shown in the drawings FIG. 1, FIG. 3, FIG. 5, the brush 4 is made of a cylindrical structure, is arranged above feeding roller 3, a brush shaft 4 is parallel to the feeding roller shaft 3.

As shown in FIG. 7, the guide grooves 7 are textured as curves along the groove length. These grooves are arranged close together in length to form a curved surface. The grooves 7 have a gap in the bottom of the groove, each of the 7 guides is located respectively opposite a row of holes 31 on feeding roller 3 and feeding roller 3 is located directly above the inlet of groove 7. In conventional cashew nuts shelling machines, guide groove 7 is usually straight groove. Since the cutter is fixed during a cutting cycle, the distance between the cutter and the guide groove depth remains constant. Therefore, when the cashew nut comes into contact with the blade, the cutting path into the nut will be a straight line. Creating a curved guide groove 7 structure as in the invention will ensure that the cutting path into the nut is curved because when it comes into contact with the cutter, the cashew nut is moving on a curved trajectory.

As shown in FIG. 5, the bar scrapers 5 are mounted on two opposing gear rings to form a hollow cylindrical frame. The scrapers 5 are parallel to each other and uniformly distributed on the aforementioned gear ring so that when moving, the upper scrapers 5 are always at a position higher than the surface of guide grooves 7. The aforementioned gear ring is driven by another rotating shaft parallel to the rotating shaft that drives the feeding roller 3.

As shown in FIG. 5 and FIG. 8, the nut pusher 6 is arranged on another rotation shaft parallel and lower than the rotating shaft that drives the feeding roller 3. The nut pusher 6 consists of identical toothed discs 61 arranged consecutively along the rotation shaft. Each corresponding toothed disc 61 faces a row of holes 31 in the feeding roller 3. The nut pusher 6 is positioned below guide grooves 7 so that each toothed disc 61 of nut pusher 6 is respectively opposite the below of one guide groove 7 and the teeth can move in groove 7.

As shown on FIG. 5, FIG. 9a and FIG. 9b, above each guide groove 7 is arranged a locating box 8 to erect the cashew nuts evenly in a certain direction before the nuts come into contact with the cutter. The concept of “erected” should be understood in a broad sense, with the meaning of arranging the cashew nuts evenly in a definite direction. This concept does not limit the fact that after being “erected”, the cashew nuts must be in a state where the vertical nut size is larger than the horizontal nut size. Accordingly, the reverse or other states of cashew nuts after passing through locating box 8 are also within the scope of the patent claim, as long as this state is the same for all cashew nuts. These different states can be adjusted by varying the distance between locating box 8 and guide groove 7. The locating box 8 has a curved shape corresponding to guide groove 7. Each locating box 8 is arranged parallel to a guide groove 7 and a distance higher than that of guide groove 7 to match the cashew nut height. The locating box 8 is also grooved opposite to guide groove 7 so that guide groove 7 and locating box 8 combine to hug the cashew nut contour.

As shown in FIG. 5, each blade holder 9 is arranged to correspond to a guide groove 7 and is located behind the locating box 8 in the direction of nut movement. The blade holder is textured to hold the cutter in a fixed position during nut shelling and has a curvilinear shape corresponding to the guide groove 7.

In a preferred embodiment, the end of guide groove 7 (which is opposite blade holder 9) is slotted in a V-groove across the groove. The tail of the blade holder 9 is also V-slotted at the corresponding opposite position.

The operating principle of the machine

The cashew nuts are poured into the feedding unit. From there, the nuts fall into feeding holes 31 on the surface of feeding roller 3. The feeding roller 3 rotates so that the nuts fall into the guide grooves 7. The toothed discs 61 will push the nuts along the guide groove 7 towards the locating box 8. At locating box 8. the cashew nuts are evenly erected in a definite direction. Scrapers 5 continue to push cashew nuts in locating box 8 down to blade holder 9 at the end of stroke in guide groove 7. When in contact with the cutter, the cashew nuts continue to move in a curvilinear motion along the groove length 7. The cutting path will thus have a curvilinear shape along the periphery of the nut shell. After passing through the cutter, the kernel was separated from the shell and dropped into the collection unit.

Above, the invention has been described through the preferred embodiments, the person with average knowledge of the respective technical field can make various transformations as long as it does not fall outside the scope of protection below.