US3575620A

US3575620A - Vibratory drive unit

Info

Publication number: US3575620A
Application number: US20765A
Authority: US
Inventors: Denver Braden
Original assignee: Illinois Tool Works Inc
Current assignee: Illinois Tool Works Inc; Kyocera International Inc
Priority date: 1970-03-18
Filing date: 1970-03-18
Publication date: 1971-04-20
Anticipated expiration: 1988-04-20

Abstract

Drive unit for vibratory part feeder utilizes a tubular cylinder as both a protective case for the unit to enclose an electromagnetic coil, and also, by angularly slotting the cylinder completely around its periphery, as a spring which cooperates with the electromagnetic coil to provide a vibratory feeding motion to parts placed in a feeder bowl which may be attached to the drive unit.

Description

United States Patent 2,926,313 2/ 1960 Wiegand Inventor Denver Braden San Diego, Calif. 20,765

Mar. 18, 1970 Apr. 20, 1971 Illinois Tool Works Inc. Chicago, Ill.

Appl. No. Filed Patented Assignee VIBRATORY DRIVE UNIT 7 Claims, 2 Drawing Figs.

US. Cl

Int. Cl

Field of Search References Cited UNITED STATES PATENTS 3,106,652 10/1963 Burt 310/17 3,155,853 11/1964 Spurlin et al.. 310/29 3,170,078 2/1965 Kuschel 310/29 3,522,460 8/1970 Spurlin 310/29 Primary ExaminerD. F. Duggan Attorneys-Robert W. Beart, Michael Kovac, Barry L. Clark and Jack R. Halvorsen ABSTRACT: Drive unit for vibratory part feeder utilizes a tubular cylinder as both a protective case for the unit to enclose an electromagnetic coil, and also, by angularly slotting the cylinder completely around its periphery, as a spring which cooperates with the electromagnetic coil to provide a vibratory feeding motion to parts placed in a feeder bowl which may be attached to the drive unit.

PATENTED APRZO I97! WWW INVEN'IOR. Denver Braden VIBRATORY DRIVE UNIT BACKGROUND OF THE INVENTION Vibratory drive units for feeding small parts are widely known and used. Typically, these units include an electromagnetic coil for driving the device quickly in one direction and a spring for returning it to its original position. In addition, a housing must be provided to cover the internal parts including the spring. The housing which is fixed to the base of the unit, must be sufficiently close to the feeder bowl to provide protection and yet have clearance between itself and the vibrating feeder bowl in order to prevent rubbing of the relatively moving parts of the device on each other.

SUMMARY It is an object of this invention to provide an extremely simple and compact vibratory drive unit which is not only effective for its purpose, but economical to manufacture.

These and other objects are accomplished by the device of the present invention which utilizes a plurality of helically arranged slots in a tubular cylinder to weaken the cylinder and permit it to function as a spring. Thus, the invention eliminates the necessity of providing either a separate spring or a space to put it. Attached to the lower end of the cylindrical spring is a base member which carries an electromagnetic coil. Attached to the upper end of the cylindrical spring is a feeder bowl support member which has an armature member affixed to its lower surface and is adapted to carry a feeder bowl on its upper surface. The armature and coil are adjustably positioned relative to each other so as to provide a magnetic airgap between them. Although it is desirable that the armature and coil never touch one another, they are positioned sufficiently close to each other so that the armature will be pulled toward the coil when the coil is energized by an alternating current such as conventional 60 Hz. current. The cross section of the web portions of the spring cylinder between the slots provide sufficient rigidity to the cylinder to prevent the armature from being moved so far as to touch the coil while yet providing sufficient resiliency to permit it to move relative to the coil. This movement of the armature naturally causes the upper end of the cylinder to be moved axially toward the lower end and also to rotate relative to it since the cylinder slots are arranged helically. Since conventional alternating current will result in a maximum voltage being reached in the turns of the coil at approximately one-quarter of a cycle, it is obvious that the feeder bowl will be quickly rotated to one extreme of its movement during the small portion of the AC cycle just prior to this point in the cycle as the coil acts against the spring cylinder. The spring cylinder may then return the feeder bowl to its initial or opposite extreme position over the remaining portions of the AC cycle. Since the movement of the bowl in one direction by the coil is very fast, the bowl will be jerked under the parts within it without causing them to move. The much slower return movement of the bowl by the energy stored in the spring cylinder will cause the parts to be moved forward by the bottom of the feeder bowl as it moves.

Although the spring cylinder has been made of steel in the preferred embodiment of the invention, it is obvious that other materials, including plastics, which have either been cast, molded or machined, could be used. Depending upon the loads to be carried by the feeder bowl, the amount of web material which is permitted to remain between the slots in the spring cylinder must be matched somewhat to the strength of coil used in order that the armature can be pulled toward the coil to provide the desired feeding movement, but without bouncing against the coil.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially sectioned side view of the vibratory drive unit of the invention showing the unit in use with the feeder bowl; and

FIG. 2 is a diagrammatic view illustrating the rotary movement of the top portion of the spring cylinder when the coil is energized.

DESCRIPTION OF THE PREFERRED EMBODIMENT The vibratory drive unit indicated generally at 10 comprises a shell or spring cylinder 12 preferably made of steel tubing which is machined so as to provide a continuous lower portion 12a, a continuous upper portion 12b, and a central portion in which helical slots 13 are formed between elongated narrow web portions 14. The lower portion 12a of the spring cylinder 12 is integrally fastened to a base member 15 by means of fasteners 16. The upper end portion 12b of the spring cylinder is fastened integrally to a feeder bowl support member 18 by means of fasteners 22.

During use of the vibratory drive unit an adjustable mounting member 24 may be placed on top of the feeder bowl support member 18 so as to provide the desired angle of slope to a flat bottomed feeder bowl 26 mounted thereon by means of mounting bolt 28. The details of the feeder bowl form no part of the present invention and are described in my copending application Ser. No. 706,010, filed Feb. 6, 1968.

Mounted on the base 15 of the drive unit is an electromagnetic coil 30 which may be vertically adjusted relative to the base 15 by means of a plurality of setscrews 32 and a plurality of mounting bolts 34. Electric power is supplied to the coil 30 through terminals 36, 38 by means of a power cord 40. An armature member 46 is mounted to the lower surface of feeder bowl support member 18 by means of a plurality of fasteners 48.

When the coil 30 is energized by a source of alternating current, a strong magnetic force will be generated by the coil during the positive portion of the alternating current cycle which will magnetically attract the armature member 46 and cause it to move across the magnetic airgap 50. This attractive movement will take place very quickly at a point just prior to the point in the alternating current cycle where the voltage is a maximum. As the voltage decreases from its maximum, the coil 30 has no effect on the armature. During the portion of the cycle where the coil is not fully energized, the stored spring energy introduced into the springlike web portions 14 is available to relatively slowly return the support 18 and the feeder bowl 26 thereon to its normal position. As previously noted, it is this slow portion of the vibratory cycle wherein parts placed in the bowl 26 are fed forwardly.

FIG. 2 illustrates the movement of an upper portion 14a of the web portion 14 to its dotted position 14a when a point 46a on the armature 46 is pulled to the dotted line position 46a it assumes when the coil 30 is energized. Since the spring cylinder 12 is round, it is obvious that the armature 46 affixed to it will rotate as well as move downwardly through the magnetic airgap 50 as the coil 30 is energized. This movement will bend each web member 14 and store energy in it which is then returned when the coil is deenergized. The airgap 50 is preferably of a width of about 0.0050.040 inch.

Iclaim:

l. A vibratory drive unit for use with a parts feeding bowl comprising:

an elongated hollow cylinder member having first and second end portions and an intermediate central portion; said first end portion being integrally fastened to a drive unit base member;

said secondend portion being integrally fastened to a feeder bowl support member.

an electromagnetic coil affixed to one of said end portions and an armature member affixed to the other of said end portions, said armature member being spaced from said coil;

said central portion of said cylinder having elongated slots arranged completely around its periphery at an angle to the axis of said cylinder so as to define a plurality of web portions of narrow width which interconnect said end portions, said plurality of web portions being sufficiently small in cross section so as to resiliently bend to permit the said end portions to move toward each other when said coil is periodically energized so as to magnetically attract and move said armature, the time required for said end portions to move toward each other by the energization of said electromagnetic coil being substantially faster than the time required for the resilient web portions to return to their unstressed positions 2. A vibratory drive unit as defined in claim 1 wherein said cylinder comprises steel tubing.

3. A vibratory drive unit as defined in claim 1 wherein said electromagnetic coil is mounted on said drive unit base member for adjustable movement relative to said armature member in order to vary the width of the magnetic airgap between said coil and armature.

4. A vibratory drive unit as defined in claim 3 wherein said adjustable movement is provided by a first plurality of adjustable fasteners which permit said electromagnetic coil to the spacing of said coil from said armature can be varied from approximately 0.005 inch to 0.040 inch in order to vary the driving power and the amount of feed movement which may be imparted to a feeding bowl attached thereto.

6. A vibratory drive unit in accordance with claim 1 wherein the time required for said end portions to move toward each other when said coil is energized is less than one-half the time required to move away from each other due to the spring force of said web portions when said coil is deenergized.

7. A vibratory drive unit in accordance with claim 1 wherein said cylinder comprises the outer housing for said unit.

Claims

1. A vibratory drive unit for use with a parts feeding bowl comprising: an elongated hollow cylinder member having first and second end portions and an intermediate central portion; said first end portion being integrally fastened to a drive unit base member; said second end portion being integrally fastened to a feeder bowl support member. an electromagnetic coil affixed to one of said end portions and an armature member affixed to the other of said end portions, said armature member being spaced from said coil; said central portion of said cylinder having elongated slots arranged completely around its periphery at an angle to the axis of said cylinder so as to define a plurality of web portions of narrow width which interconnect said end portions, said plurality of web portions being sufficiently small in cross section so as to resiliently bend to permit the said end portions to move toward each other when said coil is periodically energized so as to magnetically attract and move said armature, the time required for said end portions to move toward each other by the energization of said electromagnetic coil being substantially faster than the time required for the resilient web portions to return to their unstressed positions.

2. A vibratory drive unit as defined in claim 1 wherein said cylinder comprises steel tubing.

4. A vibratory drive unit as defined in claim 3 wherein said adjustable movement is provided by a first plurality of adjustable fasteners which permit said electromagnetic coil to be mounted at varying distances from said base member, and a second plurality of fasteners which serve to lock said electromagnetic coil to said base member but spaced therefrom in accordance with the setting of said adjustable fasteners.

5. A vibratory drive unit in accordance with claim 4 wherein the spacing of said coil from said armature can be varied from approximately 0.005 inch to 0.040 inch in order to vary the driving power and the amount of feed movement which may be imparted to a feeding bowl attached thereto.