GB2258173A

GB2258173A - Sorting apparatus

Info

Publication number: GB2258173A
Application number: GB9215900A
Authority: GB
Inventors: Tsukio Takada
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-07-27
Filing date: 1992-07-27
Publication date: 1993-02-03
Anticipated expiration: 2012-07-27
Also published as: JPH0612829Y2; HK57595A; GB9215900D0; JPH059650U; GB2258173B; DE4224783C2; ITTO920647A0; ITTO920647A1; KR930001990A; DE4224783A1; KR950004656B1; IT1257059B

Description

2238173 1 SORTING APPARATUS

BACKGROUND OF THE INVENTION FIELD OF THE INVENTION

The present invention relates to an apparatus for sorting different types of parts having different specific gravities. DESCRIPTIQN OF THE RELATED ART

Various sorting methods have been known for automatically sorting parts. A typical example of such methods employs a sieve or gauze wire which sieves and sorts parts supplied from a part feeder. In another method, slant plates are arranged at different gaps so that the parts may roll down along such plates, whereby the parts are classified according to their sizes, i.e., the sizes of the gaps between the slant plates. These two methods rely upon the difference in the dimensions or sizes of the parts. A method also has been proposed in which parts are classified and sorted according to specific gravities. For instance, parts having specific gravities not greater than;1.0 can be selected out of a batch of parts simply by being'suppled into a vessel filled with water, since such parts float on the water while other parts sink. Actually, however, it is only seldom that two types of parts are to be classified on the basis of the criterion of the specific gravity being 1.0. This sorting method, therefore, is quite impractical, although it is not impracticable from a theoretical point of view.

z The known sorting methods mentioned above are still unsatisfactory in that they require impractically long time for sorting and in that they cannot provide high sorting performance. In particular, sorting methods relying upon difference in specific gravity are not practicable, although such methods inherently posses excellent sorting performance.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a sorting apparatus which has superior sorting performance due to utilization of difference in specific gravity and which is highly practicable by virtue of the use of a liquid having a specific gravity which almost reaches about 3.0.

To this end, according to the present invention, thee is provided a sorting apparatus, comprising: a liquid tank the interior of which is divided into sections by a partition plate; liftable gauze wire cages placed in respective sections of the liquid tank; a heavy sorting liquid filling said liquid tank up to a level above the top ends of the partition plate and the cages; a washing liquid having a specific gravity smaller than the heavy sorting liquid and forming a layer on the surface of the heavy sorting liquid; and pusher mans movable along the surface of the heavy sorting liquid from one to the other section of the liquid tank.

1 3 Thus, the sorting apparatus of the present invention relies upon a difference in the specific gravity and employs a heavy sorting liquid such as tetrabromethane as the sorting solution. Tetrabromethane is a liquid which inherently has a specific gravity of about 2.95. The specific gravity of this liquid can be reduced as required by addition of an alcohol. The interior of the liquid tank is divided by the partition plate into two sections each of which receive gauze wire cages, and the liquid tank is filled with the heavy liquid, e.g., tetrabromethane, as the sorting liquid, up to a level above the top end of the partition plate. The pusher plate is disposed to move along the surface of the heavy liquid. The washing liquid should perform rinsing function and have a specific gravity significantly smaller than the heavy sorting liquid so as to float on the heavy sorting liquid, as well as small compatibility with the heavy sorting solution so as not to be mixed with the heavy sorting solution.

In operation, plurality of types of parts mixed together are put into one of the two sections of the liquid tank. Parts having greater specific gravity than the heavy sorting liquid, e.g., metal parts, naturally sink so as to be accumulated on the bottom of the cage. Parts having specific gravities between that of the heavy sorting liquid and the washing liquid float on the interface between the heavy sorting liquid and the washing liquid. Parts having specific gravities smaller than that of the washing liquid float on the surface of the washing liquid.

A_ The pusher plate is then moved to push the floating parts to the region above the other section of the liquid tank over the partition plate, and the cage holding the sunken parts is lifted out of the tank, past the layer of the washing liquid. The other cage also is lifted to catch and collect the floating parts. It is thus possible to collect different parts in different cages. The washing-liquid rinses th.e sunken parts when the cage holding such parts is lifted through the layer of the washing liquid, and interrupts any offensive smell of the heavy sorting liquid, which smell being a critical problem particularly when tetrabromethane is used as the heavy sorting solution.

The above and other objects, features and advantages of the present invention will become clear from the following description of the preferred embodiment taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic sectional side elevational view of an embodiment of the sorting apparatus of the present invention; and.

Fig. 2 is a view similar to that in Fig. 1, with a pusher plate having been moved to displace floating parts.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Fig. 1, a sorting apparatus embodying the present invention has a sorting liquid tank 1 the interior of 2 11 S which is divided into two sections 5a and 5b by a partition plate 4 placed therein. The tank sections 5a and 5b respectively receive gauze wire cages 6a and 6b which are liftable. The sorting liquid tank is charged with a heavy sorting liquid 2 which is in this case tetrabromethane liquid, up to a level which exceeds the top end of the partition plate 4 and the top ends of the cages 6a, 6b, A layer of a washing liquid 3, water in this case, is formed on the surface 7 of tetrabromethane 2, without mixing with the latter. Tetrabromethane has a specific gravity of approximately 2.95 which is about three times as large that of water.- Most of metals, excepting light metals such as aluminum, have specific gravities greater than that of the tetrabromethane, while most of inorganic materials called ceramics have specific gravities ranging between about 1.5 and about 3.0.

While the tetrabromet4ane liquid 2 having specific gravity of about 2.95 and the water 3 are held still with a distinctive boundary surface 7 maintained therebetween, a batch of various parts is supplied from a chutp 8 into the tank section 5a. Metallic parts 9 having specific gravities greater than 2.95 fall down through the layer of tetrabromethane 2 and are accumulated on the bottom of the gauze wire cage 6a. Meanwhile grinding media 10, having specific gravities not smaller than 1.0 but not greater than 2.95 fall down to the level of the boundary surface 7 but cannot fall down through the layer of the tetrabromethane 2, G. - so that they are accumulated on the liquid surface 7. It is thus possible to completely separate the metallic parts 9,9 and the grinding media 10, 10.

A pusher plate 11 mounted on the liquid tank 1 is then actuated so as to displace the grinding media 10, 10 floating on the boundary surface 7 to the region above the other tank section 5b. The pusher plate 11 is connected to the free end of a piston rod 13 of a pneumatic cylinder 12 so that it is moved as the piston rod 13 is extended, thereby pushing the grinding media 10, 10 along the boundary surface 7.

Fig. 2 illustrates the apparatus in a state in which the grinding media 10, 10 have been displaced to the rggion above the tank section 5b by being pushed by the pusher plate 11. In this state, no grinding media 10 exists in the region above the tank section 5a. As the gauze wire cage 6b in the tank section 5b is lifted, the floating grinding media 10, 10 are received in the cage 6b so as to be scooped out of the liquid tank 1. Similarly, metallic parts 9,9 in the gauze wire cage 6a in the tank section 5a are taken out of the.liquid tank 10 as the cage 6a is lifted. During the lifting of the cage 6a, the metallic parts 9,9 in the cage 6a, which have been dipped in tetrabromethane, are rinsed by the water 3 as they move across the layer of water 3. Similarly, the grinding media 10, 10 are rinsed by the water 3.

Thus, the sorting apparatus of the present invention has a double function: namely, sorting function and_washing function. The washing effect produced by the water 3 may be I insufficient and a further rinsing may be required. The layer of water 3, however, provides an appreciable primary rinsing effect.

The pusher plate 11 moves linearly along guides formed on the walls of the liquid tank 1. The use of the pneumatic cylinder 12, however, is only illustrative and the pusher plate 11 may be moved by manual effort. Lifting of the cages 6a, 6b may be performed by cranes or other lifting gears disposed above the liquid tank 1.

The sorting apparatus of the present invention can perform quick sorting of a large quantity of parts by using difference in the specific gravity between different types of parts. In addition, the sorted parts are rinsed simultaneously with the sorting. Such effects provide remarkable advantage particularly when the described sorting apparatus is applied to separation between parts which have been ground in a barrel and grinding materials used in the barrel grinding.

In the illustrated embodiment, the metallic parts 9 are the ground parts and the grinding media 10 are the grinding materials used in the grinding. Grinding media 10 of ceramics are used very often. Such grinding media generally have specific gravities ranging between 1.0 and 2.95 so that they can be quickly separated to float on the boundary liquid surface 7. It will be clear that, when other types of grinding media such as chips having a specific gravity less than 1.0 are used, such grinding media float on the surface of the water 3 without submerging down to the level of the boundary surface 7, so that they can easily be collected in the manner described.

It will also be clear that the sorting apparatus of the present invention is not applicable when an organic material having a specific gravity greater than 2.95, such as diamond, A1203 or SiC is used as the grinding media.

As will be understood from the foregoing description, the sorting apparatus of the present invention is capable of completely and quickly sorting a large quantity of parts according to specific gravities, by employing a heavy sorting liquid such as tetrabromethane and a washing liquid such as water. In particular, when tetrabromethane having specific gravity of 2.95 is used as the sorting liquid, the sorting apparatus of the present invention can be effectively used for separating metallic parts ground by barrel grinding method from the grinding medium used in the grinding. Furthermore, the layer of the washing liquid such as water, formed on the surface of the heavy sorting liquid, effectively rinses the sorted parts when they are lifted out of the liquid tank. The layer of the washing liquid also prevents offensive smell of tetrabromethane from spreading out of the liquid tank, thus contributing to improvement in the working environment.

C

Claims

WHAT IS CLAIMED IS:

1. A sorting apparatus, comprising: a liquid tank the interior of which is divided into sections by a partition plate; liftable gauze wire cages placed in respective sections of said liquid tank; a heavy sorting liquid filling said liquid tank up to a level above the top ends of said partition plate and said cages; a washing liquid having a specific gravity smaller than said heavy sorting liquid and forming a layer on the surface of said heavy sorting liquid; and pusher mans movable along the surface of said heavy sorting liquid from one to the other section of said liquid tank.

2. A sorting apparatus according to Claim 1, wherein said heavy sorting liquid is tetrabromethane having a specific gravity of about 2.95.

3. A sorting apparatus according to Claim 1, wherein said washing liquid.is water.

4. A sorting apparatus according to Claim 2, washing liquid is water.

5. A sorting apparatus according to Claim 1, wherein said pusher means is actuated by a pneumatic cylinder.

wherein said

6. A sorting apparatus according to any preceding Claim, wherein said cages are lifted by a lifting gear disposed above said liquid tank.

7. Sorting apparatus substantially as herein described with reference to the accompanying drawings.