US3921808A

US3921808A - Apparatus for sorting out defective ones from a continuous supply of moldings of bottomed cylindrical shape such as cups

Info

Publication number: US3921808A
Application number: US415554A
Authority: US
Inventors: Yasuo Sakai
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-11-17
Filing date: 1973-11-14
Publication date: 1975-11-25
Anticipated expiration: 1992-11-25
Also published as: JPS4974962A

Abstract

Moldings to be sorted are successively loaded on a first passageway at a receiving end thereof, with the bottomed end of each molding directed upward, and are caused to slide toward the exit end of the passageway. This first passageway has a first air outlet formed in its bottom surface at a point intermediate between both ends thereof for delivering air at a prescribed pressure into each of the moldings passing thereover, and a second air outlet is also provided which delivers as required a forced current of air across the first passageway to direct either defective or non-defective moldings into a second passageway branching off from the first passageway. Both the first and second air outlets are associated with a pneumatic circuit such that in the particular embodiment disclosed herein, only non-defective moldings are directed into the second passageway while defective ones are allowed to pass on toward the exit end of the first passageway.

Description

United States Patent Sakai 5] Nov. 25, 1975 APPARATUS FOR SORTING OUT DEFECTIVE ONES FROM A CONTINUOUS SUPPLY OF MOLDINGS OF BOTTOMED CYLINDRICAL SHAPE SUCH AS CUPS Appl. No.: 415,554

3,716,123 2/1973 Becker 209/80 Primary Examiner-Allen N. Knowles Attorney, Agent, or Firm-Wenderoth, Lind & Ponack [57] ABSTRACT Moldings to be sorted are successively loaded on a first passageway at a receiving end thereof, with the bottomed end of each molding directed upward, and are caused to slide toward the exit end of the passageway. This first passageway has a first air outlet formed in its bottom surface at a point intermediate between both ends thereof for delivering air at a prescribed pressure into each of the moldings passing thereover, and a second air outlet is also provided which delivers as required a forced current of air across the first passageway to direct either defective or non-defective moldings into a second passageway branching off from the first passageway. Both the first and second air outlets are associated with a pneumatic circuit such that in the particular embodiment disclosed herein, only non-defective moldings are directed into the second passageway while' defective ones are allowed to pass on toward the exit end of the first passageway.

4 Claims, 1 Drawing Figure US. Patent Nov. 25, 1975 3,921,808

APPARATUS FOR SORTING OUT DEFECTIVE ONES FROM A CONTINUOUS SUPPLY OF MOLDINGS OF BOTTOMED CYLINDRICAL SHAPE SUCH AS CUPS BACKGROUND OF THE INVENTION This invention relates to an apparatus for pneumatically sorting out defective ones from a continuous supply of moldings of bottomed, substantially cylindrical shape such as cups, caps, knobs and the like. All such moldings to be sorted by this apparatus will be referred to simply as bottomed cylindrical objects throughout the rest of this specification and in the claims appended hereto, although they may not be exactly cylindrical in shape.

Synthetic resin moldings, in particular, are subject to varieties of defects such as pinholes, cavities and deformations that are produced at the time of their manufacture, due for example to the insufficient heating of the material or to the malfunctions of the injection nozzle. Such defective products must of course be sorted out from non-defective ones prior to shipment. Conventionally, this sorting operation has been performed either manually or by means of sorting machines of the type having an indexed rotary table. Manual sorting operation is of course undesirable in view of the expenses in time and labor involved and of inevitable sorting errors. The rotary table-type sorting machines are also subject to the objection that they are highly expensive and, moreover, are capable of sorting articles of prescribed shape and size only.

SUMMARY OF THE INVENTION In view of the noted deficiencies of the prior art, it is an object of this invention to provide an apparatus for pneumatically sorting out defective ones from a continuous supply of bottomed cylindrical objects, such that the apparatus is easily adaptable for use with the objects of considerably varied shape and size.

Another object of the invention is to provide an apparatus of the character described, which is simple and inexpensive in construction and which is so compact in size that it can easily be installed in a manufacturing plant substantially as an integral part of the molding equipment.

With these objects in view and the other objects hereinafter made apparent, this invention provides an apparatus comprising a first passageway extenting generally rectilinearly, and a second passageway branching off therefrom. Bottomed cylindrical objects to be sorted are successively loaded on the first passageway at a receiving end thereof, each with its bottomed end directed upward, and are caused to travel toward the exit end of the passageway either by gravity, by forced currents of air, or by any other suitable feed mechanisms. A first air outlet is formed in the bottom surface of the first passageway at a point on the upstream side of the point where-the second passageway branches off, and a second air outlet is formed substantially in confronting relationship to the entrance of the second passageway.

Both the first and second air outlets are parts of a pneumatic circuit such that air is constantly flowing out of the first air'outlet at a prescribed, perhaps extremely low, pressure into each of the bottomed cylindrical objects traveling thereover. According to a particular embodiment disclosed hereinbelow, a back pressure arising each time a non-defective object passes over the 2 first air outlet is sensed by means included in the pneumatic circuit, and a control valve is then opened to permit a forced current of air to be delivered out of the second, air outlet across the first passageway thereby 5 directing the non-defective object into the second passageway. No substantial back pressure develops in case defective objects pass over the first air outlet, and these are allowed to travel to the exit end of the first passageway.

According to one experimental model actually constructed on the basis of the above summarized inventive concepts, it has been possible'to' continuously sort articles with a capacity of about 30 cubic centimeters at a rate of up to about 300 per minute, with a defect of down to about 1 square millimeter detected exactly.

The features which are believed to be novel and characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and mode of operation, together with the further objects and advantages thereof, will be best understood from the following description taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The accompanying drawing illustrates, partly in perspective and partly in the form of a block diagram, a preferred embodiment of this invention.

DESCRIPTION OF- THE PREFERRED EMBODIMENT As seen in the drawing, the apparatus according to the invention includes a casing 10 adapted to encase various means constituting a pneumatic circuit and so forth, the pneumatic circuit being represented in the form of a block diagram in the same drawing. A first passageway 11 for a continuous stream of bottomed cylindrical objects 12 is defined generally rectilinearly on the top of the casing 10 by a pair of guides 13 serving as side walls of the passageway. Although not clearly seen in the drawing, it is assumed that the first passageway 1 1 is set at a suitable angle to the plane of the horizon so that the successive bottomed cylindrical objects 12 are fed by gravity from the receiving end to the exit end, both not shown, of the passageway. It is therefore desirable that the surfaces defining this first passageway 11 be so smooth that no substantial frictional resistance is offered to the sliding motion of the bottomed cylindrical objects 12.

A further guide 14 in the form of a sheet of stainless steel or the like bent into the shape of an L is fastened to the front face of the casing 10 in order to readjust, if necessary, the positions of the successive bottomed cylindrical objects 12 as they are fed along the first passageway 1 l. The position of this guide 14 relative to the bottom surface of the first passageway 11 is adjustable by the manual turn of thumbscrews 15 on bolts 16 that are inserted through respective slots 17 of the guide 14.

The first passageway 11 has a first air outlet 18 formed in its bottom surface in a position intermediate between both extremities thereof, or perhaps in a position closer to the exit end of the passageway situated to the right as seen in the drawing. Air is constantly flowing out of this first air outlet at an extremely low pressure, as hereinafter referred to in more detail. A pressurizingfeed roll 19 made for example of rubber of suitable hardness is revolvably mounted above the first air outlet 18 in order to feed the successive bottomed 3 cylindrical objects 12 in close sliding contact with the bottom surface of the first passageway l l as they travel over the first air outlet 18.

The pressurizing feed roll 19 is in constant rotation, being fixedly mounted on one end of a shaft 20 revolvably supported by a pair of bearings 21 and driven by an electric motor 22 via an endless belt 23 running over a pair of terminal pulleys 24. Although not shown in the drawing, it is assumed that at least the bearings 21 are supported on a mount which is movable up and down in order to adjust the position of the roll 19 relative to the bottom surface of the first passageway 11 in accordance with the height of the various bottomed cylindrical objects to be sorted by this apparatus.

A second air outlet 25, preferably with a nozzle constriction, is provided through one of the lateral guides 13 of the first passageway l 1 in a position on the downstream side of the first air outlet 18 and at a prescribed distance therefrom. Air under pressure is to be delivered out of this second air outlet 25 across the first passageway 1 1 whenever required, such that a desired one of the bottomed cylindrical objects 12 which has just emerged from under the pressurizing feed roll 19 is sent out into a second passageway 26 branching off from the first passageway 11 at a suitable angle thereto. This second passageway 26 may also be set at an angle to the plane of the horizon to make possible the gravity feed of the objects which have been fed therein by the forced current of air from the second air outlet 25.

For delivering air out of the first and

second air outlets

18 and 25 as aforesaid, a source of compressed air is provided at 27 in which air is compressed to a pressure of, say, from about 3 to 10 kilograms per square centimeter. This compressed air from the source 27 is delivered via a stop valve 28 to a filter 29 where the air is separated from its water, oil and other undesirable contents. The thus-filtered air is directed, on the one hand, to a precision pressure regulator 30 where the pressure of the air is reduced to, say, about 0.2 kilogram per square centimeter. The air of this reduced pressure is then delivered to the first air outlet 18 via a metering valve 31 and a conduit 32.

The air from the filter 29 is directed, on the other hand, to a high pressure regulator 33 where the pressure of the air is regulated to a value within the range of, say, from about 2 to 3 kilograms per square centimeter, The air of this. pressure range is then delivered, as required, to the second air outlet 25 at the end of a conduit 34 via a control valve 35 of the type represented symbolically in the drawing.

The operation of this control valve 35 is under the control of a circuit 36 of well known construction based on the principles of fluidics (hereinafter referred to as the fluidic circuit). This fluidic circuit 36 is communicated via a pneumatic amplifier 37 with the aforesaid conduit 32 leading to the first air outlet 18.

Although not essential to this invention, the fluidic circuit 36 can be communicated with an electropneumatic transducer 38 which in turn is connected to a counter 39 of well known type that produces an output pulse each time it receives a preassigned number of input pulses. The counter 39 can be further connected to a totalizing counter 40 capable of registering and visually indicating a total number of the output pulses from the counter 39. Furthermore,

air gauges

41 and 42 may be equipped to the

conduits

43 and 44 extending between the precision pressure regulator 30 and the metering valve 31 and between the high pressure regulator 33 and the control valve 35, respectively, to permit visual observation of the pressures of the air streams flowing out of the

respective pressure regulators

30 and 33.

In the operation of this preferred embodiment of the invention, the bottomed cylindrical objects to be sorted are successively loaded on the first passageway 11 at the receiving end thereof by any suitable means, not shown, in such a manner that each object is placed with its bottomed end directed upward as seen in the drawing. Fed by gravity along the first passageway 11 in a substantially streamlined manner, the successive bottomed cylindrical objects 12 travel under the guide 14 and reach the first air outlet 18, in which position each object is pressed down against the bottom surface of the first passageway by the pressurizing feed roll 19 so that the airflowing out of the first air outlet at an extremely low rate will not escape through any negligible degree of deformation or irregularity at the lower edge of the object.

Thus, in case the particular bottomed cylindrical object traveling over the first air outlet 18 is non-defective, a back pressure develops to such an extent that a reversed flow of air takes place through the conduit 32. This reversed air flow is unable to pass through the metering valve 31 and is, instead, directed into the amplifier 37, which amplifier is effective to produce an output signal in response to such back pressure of not less than a prescribed value. This output signal from the amplifier 37 is delivered to the fluidic circuit 36, which circuit then operates to open the control valve 35 and hence to permit air under pressure to be delivered out of the second air outlet 25. Since then the aforesaid non-defective bottomed cylindrical object is already released from the pressurizing feed roll 19, the object will be blown out into the second passageway 26 and will succeedingly travel along the same by gravity to be deposited in a receptacle or the like, not shown, at the exit end of this second passageway.

On the other hand, in case the bottomed cylindrical object traveling over the first air outlet 18 is defective, the air flowing from the first air outlet will bleed through the defective part or parts of the object. No substantial back pressure develops in this case, so that the defective object is allowed to travel past the second air outlet 25 and is caused to drop into a receptacle or the like, also not shown, at the exit end of the first passageway 11.

It will be apparent that the counter 39 produces its output signal each time it counts a predetermined number of nondefective bottomed cylindrical objects 12. This counter output signal can be utilized for the automatic control of the succeeding packaging operation or the like.

While the various objects of the invention, either explicitly stated or otherwise setforth, are believed to be fully accomplished by the preferred embodiment disclosed herein, it will be easy for those skilled in the art to devise many modifications or changes of such specifically recited embodiment. For instance, instead of directing non-defective bottomed cylindrical objects into the second passageway 26 by the forced current of air from the second air outlet 25 as in the foregoing disclosure, the pneumatic circuit represented in the form of a block diagram in the accompanying drawing can easily be so modified that only defective objects will be guided into the second passageway. Moreover, while in the illustrated embodiment of the invention the successive bottomed cylindrical objects 12 are fed by gravity along the first and

second passageways

11 and 26, the same object can of course be accomplished by belt conveyors, by roll conveyors, by forced currents of air. or by any other similar feed mechanisms.

All such modifications, substitutions or changes are intended in the foregoing disclosure. It is therefore appropriate that the invention be construed broadly and in a manner consistent with the fair meaning or proper scope of the invention as sought to be defined by the following claims.

I claim:

1. An apparatus for sorting out defective ones from a continuous supply of bottomed cylindrical objects, comprising in combination:

a first passageway for the bottomed cylindrical objects having a receiving end and an exit end, said bottomed cylindrical objects being successively loaded on said first passageway at said receiving end thereof in such a manner that each of said bottomed cylindrical objects is placed with its bottomed end directed upward;

means for successively feeding said bottomed cylindrical objects along said first passageway from said receiving to said exit end thereof;

a first air outlet formed in the bottom surface of said first passageway at a point intermediate between said receiving and said exit end thereof, said first air outlet being adapted to ascertain the presence of any defect in each of said bottomed cylindrical objects traveling thereover by delivering air therein at a prescribed pressure;

a second passageway branching off from said first passageway at a point on the downstream side of said first air outlet;

a second air outlet for delivering a forced current of air across said first passageway whereby said bottomed cylindrical objects can be directed into said Second passageway; and

a pneumatic circuit associated with said first and second air outlets, said pneumatic circuit being effec- 6 tive to cause said second air outlet to direct only a predetermined one of defective and non-defective classes of said bottomed cylindrical objects into said second passageway while the other class of said bottomed cylindrical objects are allowed to travel to said exit end of said first passageway.

2. The apparatus as recited in claim 1, wherein said pneumatic circuit comprises:

a source of compressed air;

first pressure regulating means for regulating the pressure of the air from said source;

a first conduit communicating said first pressure regulating means with said first air outlet;

second pressure regulating means for regulating the pressure of the air from said source;

control valve means communicated with said second pressure regulating means, said control valve means being normally closed;

a second conduit communicating said control valve means with said second air outlet; and

fluidic circuit means effective to open said control valve means in response to the development of a back pressure in said first conduit;

whereby only non-defective ones of said bottomed cylindrical objects are directed into said second passageway by the forced current of air delivered out of said second air outlet.

3. The apparatus as recited in claim 1, further including pressurizing feed means for feeding each of said bottomed cylindrical objects at least over said first air outlet in close sliding contact with the bottom surface of said first passageway, said pressurizing feed means comprising a roll rotatably supported above said first passageway, and drive means for imparting rotation to said roll.

4. The apparatus as recited in claim 3, wherein the position of said roll is variable toward and away from the bottom surface of said first passageway to adjust to the varied height of the bottomed cylindrical objects to be sorted by the apparatus.

Claims

1. An apparatus for sorting out defective ones from a continuous supply of bottomed cylindrical objects, comprising in combination: a first passageway for the bottomed cylindrical objects having a receiving end and an exit end, said bottomed cylindrical objects being successively loaded on said first passageway at said receiving end thereof in such a manner that each of said bottomed cylindrical objects is placed with its bottomed end directed upward; means for successively feeding said bottomed cylindrical objects along said first passageway from said receiving to said exit end thereof; a first air outlet formed in the bottom surface of said first passageway at a point intermediate between said receiving and said exit end thereof, said first air outlet being adapted to ascertain the presence of any defect in each of said bottomed cylindrical objects traveling thereover by delivering air therein at a prescribed pressure; a second passageway branching off from said first passageway at a point on the downstream side of said first air outlet; a second air outlet for delivering a forced current of air across said first passageway whereby said bottomed cylindrical objects can be directed into said second passageway; and a pneumatic circuit associated with said first and second air outlets, said pneumatic circuit being effective to cause said second air outlet to direct only a predetermined one of defective and non-defective classes of said bottomed cylindrical objects into said second passageway while the other class of said bottomed cylindrical objects are allowed to travel to said exit end of said first passageway.

2. The apparatus as recited in claim 1, wherein said pneumatic circuit comprises: a source of compressed air; first pressure regulating means for regulating the pressure of the air from said source; a first conduit communicating said first pressure regulating means with said first air outlet; second pressure regulating means for regulating the pressure of the air from said source; control valve means communicated with said second pressure regulating means, said control valve means being normally closed; a second conduit communicating said control valve means with said second air outlet; and fluidic circuit means effective to open said control valve means in response to the development of a back pressure in said first conduit; whereby only non-defective ones of said bottomed cylindrical objects are directed into said second passageway by the forced current of air delivered out of said second air outlet.