US3795307A - Small parts feeder system - Google Patents

Abstract

A small parts feeder system having a transmission unit and a platform engagement mechanism. The system includes a movable platform upon which a stack of small parts may be placed and a lever-block combination for selectively engaging a rotatable screw which provides the motive force to the platform. The force is transmitted to the screw through a miter gear train.

Description

limited States Patent [191 Toth et a1. 1 Mar. 5, 1974 [54] SMALL PARTS FEEDER SYSTEM 3,345,038 [0/1967 Taylor 254/86 R [76] inventors: John E. Toth, 13544 Orchard Gate W197 A X Rd., Poway, Calif. 92064; Arthur G. Gram, 7014 Colorado -7 La Primary Examiner-Edward A. Sroka Mesa, Calif. 92041 [22] Filed: Nov. 6, 1972 211 App]. No.2 303,792 ABSTRACT A small parts feeder system having a transmission unit [52] 11.8. C1. 198/218, 198/108 and a l f engagement mechanism The systam [51] int. Cl 365g 25/04 includes a movable platform upon which a Stack of [58] Field of Search 198/1, 108, 218; 248/405; Sma" parts may be placed and a levepblock Combina- 221/279; 254/98 103; 214/8-5 A tion for selectively engaging a rotatable screw which provides the motive force to the platform. The force is [56] References cued transmitted to the screw through a miter gear train.

UNITED STATES PATENTS 2,678,859 5/1954 Zuzzi 248/405 5 Claims, 7 Drawing Figures PATENTEDHAR 51914 3,195,307

SHEET 1 0f 2 SMALL PARTS FEEDER SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feeder system and more particularly to a small parts feeder system which efficiently and effectively transports small parts such as those commonly found in the electronic component industry, the feeder system including in combination a transmission unit and a platform engagement mechanism. I

2. Description of the Prior-Art Numerous devices have been developed in response to the manufacturing requirements of miniature electronic components. This is due primarily to streamline manufacturing processes in order to lower manufacturing costs and thereby the ultimate costs of the components. For example, one such apparatus is disclosed in a previously filed patent application wherein the apparatus functions to automatically sort parts as a function of thickness or width dimension. See United' States Patent Application titled Precision SortingApparatus, Ser. No. l6l,735,' filed on July 12, 1971.

With the advent of such devices, there has been a need to speed the rate at which components or parts are fed to the sorting device in order for the sorting device to be used to its fullest capacity. It is to be noted that the type of components or parts which are handled are generally relatively-small and oft times fragile. Thus the design of any type of automatic feeder system would thereby be restricted in size and handling parameters. By way of example, the inventors have found that a variation ofa bulk transfer device, such as a conveyor belt or a continuous chain of buckets, would not be particularly suitable. Other design criteria thought to be noteworthy include a capability for feeding parts singly and at a precisely controlled rate.

Some types of components may be handled by bowl feeders which operate on a vibration principle. Physically a bowl feeder consists of a large metal dish mounted upon a vibrator and having side walls specially grooved to accept and align the components to be fed. Constant vibration causes the components, which are simply dumped into the dish, to align themselves in the groove of the side wall and then slowly progress in a single file to an exit location. The problem with such a device is that vibrations by their very nature length, the cross-sections being shaped to accept the device to be fed. Generally such a magazine feeder is positioned above the device to be fed with the parts being dropped singly under the influence of gravity. While such a feeder system is extremely simple in construction, various problems exist such as the difficulty in initially loading the magazine and the handling of the magazines each time it is necessary to position a fully loaded magazine. In addition, there is a need for a different magazine for components having different sizes and shapes.

Of course any system which is developed must be efficient and must be effective in operation. Further, it is always desirable for the system to be simply constructed, reliable in operation and low in manufacturing costs.

SUMMARY OF THE INVENTION The present invention meets all of the above objectives and solves the problems which have been mentioned above by providing a feeder system for moving small parts in a preselected manner comprising in combination a housing; a parts platform connected to the housing and movable upwardly and downwardly; a power transmission unit including a pair of miter gears, one of which is connected to a source of power and the other of which is connected to an elongated means for rotating, the elongated means being connected to the housing; and a platform engagement mechanism connected to the housing and including a movable block having a recess for engaging the elongated means, lever means connected to the block and pivotally connected to the housing for moving the block away from engagement with the elongated means, and biasing means connected to the housing and block for inducing contact of the block and the elongated means. In more detail the power transmission unit includes an elongated .screw fixed in a direction parallel to'the longitudinal axis of said screw while the platform engagement mechanism includes a screw thread recess and a spring.

It is the general aim of the present invention to provide a simple, reliable and efficient small parts feeder system. An important aspect of the invention is that the feeder system be able to handle a variety of different sized components or parts, be capable of feeding the parts at a uniform rate, be unabusive to the parts being handled, and be sufficiently flexible to handle a solid part from which is cut smaller parts just prior to the smaller parts leaving the feeder system. Still another object of the present invention is to provide a system which may be totally automatic so as to be ameanable to sequencing with the device to be fed. Finally, an object of the present invention includes the provision of reliable and simple transmission unit and platform engagement mechanisms.

Other objects and advantages of the invention will appear from the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a block diagram illustrating in a simplified fashion the small parts feeder mechanism of the present invention.

FIG. 2 is a perspective view of the small parts feeder system as connected to a sorting apparatus like that described in the above-identified United States Patent Application.

FIG. 3 is an elevational sectional view of the transmission unit taken along line 3-3 of FIG. 2.

FIG. 4 is a plan sectional view of the platform engagement mechanism taken along line 4-4 of FIG. 2.

FIG. 4a is a partial plan view of the platform engagement mechanism like that shown in FIG. 4 with the mechanism in a disengaged position.

FIG. 5 is an elevational view of the platform engagement mechanism shown in FIG. 4, taken along line 5-5 of FIG. 4.

FIG. 6 is an elevational view of a portion of the platform engagement mechanism illustrating a block having a screw thread recess taken along line 6--6 of FIG. 4a.

DESCRIPTION OF THE PREFERRED EMBODIMENT While the present invention is susceptible of various modifications and alternative constructions, an illustrative embodiment is shown in the drawings and will herein be described in detail. It should be understood however that it is not the intention to limit the invention to the particular forms disclosed; but on the contrary the invention is to cover all modifications, equivalences and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring now to FIG. I, there is illustrated in diagrammatic form a small parts feeder mechanism 10 having a power source such as the motor I2 which is connected to an elongated rotatable screw 14 through miter gears (not shown in FIG. I). Disposed parallel to the screw is a guide shaft 16 which like the screw is constrained by a lower base 18 and an upper base 20, the upper base including a housing 22. Movable along the screw and the guide rail is a platform 24 having a platform engagement mechanism 26. In operation the load of small parts to be transported is placed upon the platform 24 and moved upwardly by action of the screw on the platform whereby the parts are singly emitted as depicted by the arrow 28.

As already mentioned, one object of the present invention is to provide a reliable but yet simply constructed transmission unit for the feeder system. There is illustrated in perspective in FIG. 2 a feeder system connected operatively to a precision sorting apparatus 30. Mounted to the sorting device is the motor 12 which may be connected by any suitable drive mecha nism such as a pulley belt 32, FIG. 3, to a pulley 34. Referring to FIG. 3, the pulley in turn is mounted to a shaft 36 at one end while a miter gear 38 is mounted at the opposite end. The shaft is attached to the housing 22 in any suitable manner such as by the bearings 40 and 42. At right angle to the miter gear 38 and of equal size is a second miter gear 44 which is connected at the end of the screw 14. The screw also is mounted in the housing 22 using a suitable bushing 46. It may now be readily appreciated that the screw is fixed so as to rotate about an axis coincident with its central longitudinal axis but is otherwise stationary (such as in a direction parallel to its longitudinal axis). What is now also apparent is that the transmission unit is simply constructed and yet highly reliable; and it is an efficient means for transmitting motion from the motor to the screw.

The reliability and yet simplicity of construction is again shown by reference to FIG. 2. There is illustrated the platform 24 having an upper surface 50 upon which may be stacked a number of parts 52 to be fed to the precision sorting apparatus 30. As mentioned earlier, the platform 24 is movable in a direction parallel to the longitudinal axis of the screw. During this movement the platform is guided by the screw and by the guide shaft 16. This allows the platform to start from a lower position such as illustrated in FIG. 2 and move upwardly until the upper surface 50 is parallel to an upper portion of a chute 54 along which the parts 52 may slide before entering the precision sorting apparatus. In the preferred embodiment, the stack of parts are supported by the surface 50 and also restrained by a pair of walls 56 and 58 which are set at right angle to one another. The walls are part of a housing generally designated 22 and includes an upper base portion 60, the chute 54 and the lower base portion 61.

Referring to FIGS. 4, 4a, 5 and 6, there is illustrated in greater detail the construction of the platform and especially a platform engagement mechanism generally designated 66. Referring to FIG. 4a, the engagement mechanism includes a lever 68 which is connected to one end of an arm 70. The other end of the arm is connected to a block 72 having a screw threaded recess 74. Positioned against the block 72 is a coil spring 76 which provides a biasing force against the block tending to urge it toward the screw 14. By having the screw thread 74 correspond to the thread ofthe screw 14, mating occurs between the two if the block is allowed to come into engagement with the screw. By causing engagement and rotating the screw, the platform is moved along the screw.

The arm is pivoted about a pivot pin 78 so that if the lever is pushed toward the platform as indicated by the direction of the arrow 80, the arm, as well as the block, is moved in a direction depicted by the arrow 82. This will cause the block to move away from the screw and free the platform from any constraint caused by the screw. Thus the platform may be moved anywhere along the screw, guidance being offered by the screw and by the guide shaft, depending upon the height of the stack of parts to be fed. Since movement of the arm and block in the direction of the arrow 82 also causes the spring 76 to compress, there is created a biasing force in the direction depicted by the arrow 84. Once pressure is released from the lever 68, the block and the arm will move in the direction of the arrow 84 to engage the screw once again. Hence, the platform may now be moved in a direction parallel to the longitudinal axis of the screw in a very easy manner simply by depressing the lever 68 and then releasing it once the correct position has been found. The elements of the mechanism are quite simple and therefore relatively inexpensive.

The platform engagement mechanism is shown in more detail in FIGS. 4 and 5 where the arm 70 is shown pivoted about the pivot pin 78, and there are two springs 76, 760 used to bias the block 72 into engagement with the screw 14. The block has two recess portions 74 and 74a. It is also noteworthy the the arm 70 while connected tothe block 72 is not attached but only abutts the block at a hump 85.

To further exemplify the simplicity and ease of operation of the feeder system, reference is once again made to FIGS. 1 and 2 where there is shown a switch connected to the housing 22 in a position so that when the platform is at its highest position, the switch will be activated. As is shown in FIG. I, the switch is connected to the motor and may act to shut the motor off. In this variation, an operator would then provide a new stack of parts 52 and adjust the platform to the proper height and then reactivate the motor such as by depressing the switch 90 once again. Another variation of the present invention includes the placement of a switch 92, FIG. 1, at the base 18 so as to make contact at the end of a downward movement of the platform. In this variation, the motor would be reversible as opposed to a non-reversible type in the first mentioned variation. Thus in the second variation activation of the switch 90 by the upwardly moving platform would cause the motor to reverse so as to return the platform to its lower position where the platform can be reloaded with a new stack of parts. Upon reaching the lower position switch 92 is activated; depending upon the desires of the operator; activation of the switch 92 may cause the motor to again reverse so as to drive the platform in an upwardly direction. Or appropriate circuitry may be added to cause a time delay after the switch 92 has been activated. This will delay the upward movement of the platform for'some predetermined time.

Briefly reviewing the operation of the apparatus once again, it is understood that the feeder system functions in conjunction with a device to be fed which is exemplified by the precision sorting apparatus illustrated in H6. 2. The sorting apparatus has a closely controlled spacing which is set to some predetermined dimension. Parts which are smaller than the spacing will pass into a first collection container. Parts which are larger than the spacing will cause the apparatus to direct the part into a second collection container. It is to be understood that relatively small parts are being handled singularly at a relatively rapid rate so that if the sorting apparatus is to function efficiently the feeding system must provide the parts to be measured singly and at a sufficiently rapid rate. Starting with the platform at its lower position and a fresh stack of parts to be fed, the motor is activated causing the platform to move upwardly by the rotation of the screw against the threaded block. As each part reaches the chute 54 it will simply slide off the adjacent lower part and proceed under the influence of gravity into the sorting apparatus. The motor l2 may be a dc. motor; this means the motor speed may vary as a function of voltage. Or the motor may be operable on ac. current with a mechanical speed changer. The rate at which the feeding system serves parts to the sorting apparatus depends upon the rate of rise of the platform which in turn depend upon the rate of rotation of the screw. The rate of the screw is a function of the speed of the motor used. Obviously, the motor speed may be set at a convenient level in order to insure that the sorting apparatus is being fed at an optimum rate. Of course, the optimum rate depends upon the dimensions of the parts being fed since a larger part would require a greater motor speed in order to feed at the same rate as a smaller part.

Once the platform has reached its upper most limit contact will be made with the switch 90 which in one embodiment simply shuts down the motor until reactivated by an operator. If such is the case, the operator depresses the lever 68 to disengage the platform from the screw, lowers the platform to a desired height, and then loads a stack of parts. The operator then simply depresses the switch again to operate the motor. In the other variation mentioned. activation of the switch 90 causes the motor to reverse thereby driving the platform downwardly. lt is of course understood that the reverse speed of the motor may be substantially faster than the feeding rate of the motor. Upon being driven to the base IS, a second switch 92 is activated which may reverse the direction of the motor causing the platform to begin immediately rising again or there may be a predetermined time delay to allow a slower reloading of a stack of parts before the platform starts upwardly again.

It is quite clear that the present apparatus is simply constructed yet highly reliable and extremely efficient. Further, the feeding device may handle a variety of different sized parts; by changing the motor speed such as by a control knob 96, FIG. 2, a uniform feeding rate may be achieved should it be desired regardless of part size. It is further understood that the feeding system does not abuse the parts to be fed; once the parts are stacked on the surface 50 they will simply slide relative one another before entering the sorting apparatus. Finally, the apparatus may be fully automatic.

Still a further variation of the present device is shown in FIG. l in which a cutter 98 such as a rotating blade or other suitable device may be mounted to the housing 22 and be positioned to slice a predetermined length from a solid core of material located upon the platform 50. This might allow parts to be fed into the sorting apparatus which are first being cut to size just prior to entering the sorting apparatus. In certain circumstances. the placement of such a cutter may make a specific manufacturing operation more efficient.

It is to be noted that the platform 50 moves upwardly at an angle relative the vertical. Choice of the angle is of some importance to insure that the individual parts of a stack of parts slide relative one another. That is, the upper most part must be at a sufficient angle to overcome the force of friction preventing movement. it has been found that the slope necessary may be readily determined simply by matching the coefficient of friction of a part sliding on another part of identical material to the tangent of the angle relative a reference vertical. If the tangent is greater than the coefficient of friction then the parts will readily slide relative one another. For example if small ceramic plates are the parts which are being fed, (these types of parts are commonly used in the electronic industry for making electronic elements as well as acting as miniature circuit boards) a slope of 35 from the vertical is sufficient. This provides a tangent of about 0.7 while the coefficient of friction of a ceramic part is roughly equal to 0.4 for the type ceramic common in the electronic industry.

I claim:

1. A feeder system for moving small parts in a preselected manner comprising in combination:

a housing;

a parts platform connected to said housing and movable upwardly and downwardly;

a power transmission unit including a pair of miter gears, one of which is connected to a source of power and the other of which is connected to an elongated means for rotating, said elongated means connected to said housing; and

a platform engagement mechanism connected to said housing including a movable block having a recess for engaging said elongated means, lever means connected to said block and pivotally connected to said housing for moving said block away from ongagement with said elongated means and biasing means connected to said housing and block for inducing contact of said block and said elongated means.

block recess comprises a screw thread and biasing means comprises a spring.

5. A feeder system as claimed in claim 4 wherein said elongated means comprises an elongated screw fixed in said housing in a direction parallel to the longitudinal axis of said screw.

Claims (5)

1. A feeder system for moving small parts in a preselected manner comprising in combination: a housing; a parts platform connected to said housing and movable upwardly and downwardly; a power transmission unit including a pair of miter gears, one of which is connected to a source of power and the other of which is connected to an elongated means for rotating, said elongated means connected to said housing; and a platform engagement mechanism connected to said housing including a movable block having a recess for engaging said elongated means, lever means connected to said block and pivotally connected to said housing for moving said block away from engagement with said elongated means and biasing means connected to said housing and block for inducing contact of said block and said elongated means.

2. A feeder system as claimed in claim 1 wherein said housing includes a guiding surface along which said platform is movable.

3. A feeder system as claimed in claim 2 wherein said elongated means comprises an elongated screw fixed in said housing in a direction parallel to the longitudinal axis of said screw.

4. A feeder system as claimed in claim 2 wherein said block recess comprises a screw thread and biasing means comprises a spring.

5. A feeder system as claimed in claim 4 wherein said elongated means comprises an elongated screw fixed in said housing in a direction parallel to the longitudinal axis of said screw.

Images