US1437014A - Vibrator - Google Patents

Description

H. PRELL. VIBRATOR.

APPLICATION FILED AUG. 13, 1920.

Patented Nov. 23, 1922 I/0 all:

Jim? 2271-! Z2 I E 4 5 Patented Nov. 28, 1922.

UNITED STATES 1,437,014 PATENT OFFICE.

HENRY PRELL, OF CHICAGO, ILLINOIS.

VIBRATOR.

Application filed August 13, 1920. Serial No. 403,384.

To all whom it may concern Be it known that I, HENRY PRELL, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Vibrators, of whicn the following is a specification.

This invention relates to vibrators for foundry use and is an improvement upon the vibrator shown, described and claimed in my prior application Ser. No. 235468 filed May 20, 1918.

The object of the present invention is to generally simplify and improve the construction, reduce the number of parts and secure increased etficiency and better results at lower cost.

Further objects of the invention are in part obvious and in part will appear more in detail hereinafter.

The invention comprises the construction and arrangement of parts hereinafter de scribed and claimed.

In the drawings, which represent one suitable embodiment of the invention, Fig. 1 is a sectional elevation on the line 1-1, F i 3; Fig. 2 is a side view from the left, Fig. 1.

a sleeve being omitted; Fig. 3 is a plan view;

Fig. 4 is a front elevation; Fig. 5 is an end view of the hammer of vibrating member; Figs. 6 and 7 are plan views of certain washers; and Figs. 8 and 9 are end and side views of an insulating terminal block.

The vibrator shown in the drawings comprises a hollow casing or body of suitable form, shown as formed of two members 1, 2 connected by cap screws 3 threaded through openings in member 2 into threaded holes in bosses 1 on member 1. Said two members are faced off smooth at 5 so as to fit closely and exclude dirt, moisture and foreign matter to the chamber 6 between the members. Both members are preferably slotted radially, such as by a narrow saw cut, as illustrated at 7, to cut the induced current. The bosses i are also built up fairly high and their edges 8 extend in wardly appreciably to interrupt the rcgula surface of contour and assist in cutting in duced current, as well as for the purpose of increasing the exposed heat radiating surface. Member 1 is also provided with a perforated lug or ear 9 for attaching the device to the flask, mold or other foundry device or apparatus to which vibrations are to be communicated.

In the relatively large portion of chamber (3 which is in member 1 is a ring like ma net coil 10 the wires from which are led to binding posts or screws 11 in an insulating block 12 secured to member 1 by a pin 13 and enclosed within a sleeve 14 through which the conductor wires 15 are passed. Coil 10 may be held in place in any suitable manner but usually is clamped firmly between the finished surface 5 of member 2 and the end wall of chamber 6 in member 1 as shown in Fig. 1. Said coil surrounds a vibrating member or hammer 16 which is of cylindrical form with a sliding fit in the chamber portion 6 of member 2 from which it protrudes into the space at the center oi? the coil. This cylindrical hammer has a central through opening 17 in which is a shoulder 18. It is also provided with a suitable num ber (12 being shown) of radially extending slots 19 which. extend from the coil and nearly toward the opposite end where adja cent segments are connected by the bridges 20. One slot, marked 19 extends clear through from end to end to break or reduce the induced current and avoid consequent heating.

Vithin the larger portion of the opening 17 is a compressionspring 21 seated at one end on the shoulder 18 and at its opposite end surrounding the head of a screw 22 which clamps firmly to the member 1 a washer like abutment 23 shown in Fig. 7. This washer is slotted radially at 24 for the same purpose as the hammer and is formed with a sligl'it dish or concavity so that when it is bent down flat to its seat by screwing up the screw 22, it forms a firm solid abutment or anvil to receive the blow and also locks the screw against turning. If desired a thin layer 25 of nonmagnetic material. such as a layer of tracing cloth coated with shellac, may be inserted beneath the washer to insulate it from member 1 so far as possible and thereby break the magnetic efier-t and avoid residual magnetic efiect and stick ing, although this is not essential and may be omitted.

In the bottom of the chamber 6 in member 2 is a washer or abutment shown in detail in Fig. 6. This washer is preferably made of such diameter that it can be forced or driven solidly into place at the bottom of chamber by heavy pressure and will become in effect an integral part of the cap or cover 2. If desired, the washer may be coated with shellac and a suitable number of paper or other thin shims can be inserted under the washer to give it a solid bearing on a smooth surface and to also properly locate the sliding member 16 in the chamber. At the center of the washer is an opening 27, preferably under cut, as at 28, to form a shoulder around which a suitable tool can be hooked to pull the washer out when necessary. it is also provided with a series of radial grooves or channels 29.

The operation is as follows: The conductor wire 15 is connected to a suitable source of alternating current, although in some instances the vibrator may be operated from a direct current source controlled by an interrupter. l/Vith alternating current the hammer 16 reciprocates longitudinally in chamber 6 in step with the cycles of the alternating current. Said hammer is made of the proper length so that a small clearance of say seven hundredths (.07) of an inch is left between its end and the washer 23. Therefore, when it moves in one direction under the influence of the coil 10 it strikes the abutment or washer 23 and when it moves in the other direction responsive to the. change in direction of the current and also to the effect of spring 21 it strikes or engages the abutment or washer 26 with a blow. Dash pot effect is avoided by the central opening 17 in the hammer and the radial channels 29 in washer 26 which allow free circulation of air and prevent cushioning effect.

The hammer 16 and washer 23 are preferably made of cold rolled steel which is case hardened to give it a hard wear resisting outer surface but which leaves the inner por tion of the material soft, which assists the changes in magnetic polarity. Washer 26 may be made of fiber or other relatively soft and non magnetic material. The casing members land 2 are usually of annealed soft gray iron to avoid these parts heating through hysteresis, and which also insures a maximum blow.

Since the hammer is cylindrical and is guided in a center chamber, only a single spring is necessary and there is no tendency of the hammer to tilt or become askewin its chamber with consequent interference with its proper movement.

What I claim is:

1. A vibrator for molding devices, coinprising a hollow casing having a central cylindrical chamber, provided with large and small portions, a cylindrical hammer member guided in the smaller part of said chamber, and a coil surrounding said member in the larger part of said chamber.

2. A vibrator for molding devices, comprising a hollow casing having a central cylindrical chamber, provided with large and small portions, a cylindrical hammer member guided in the smaller part of said chamber, and a coil surrounding said member in the larger part of said chamber, said casing being provided with abutments opposite the ends of said member.

3. A vibrator for molding devices, comprising a hollow casing having a central cylindrical chamber, provided with large and small portions, a cylindrical hammer mem ber guided in the smaller part of said chamber, and a coil surrounding said member in the larger part of said chamber, and means arranged to permit free circulation of air around said member to avoid cushioning effect.

at. A vibrator for molding devices, com prising a hollow casing having a chamber, a coil in said chamber and a reciprocating hammer member actuated thereby, said member having a series of radially and transversely extending slots one of which extends longitudinally from end to end thereof.

5. A vibrator for molding devices, comprising a hollow casing having a chamber, a coil in said chamber and a reciprocating hammer member actuated thereby, said member having a central opening, and a compression spring in said opening.

6. A vibrator for molding devices, comprising a hollow casing having a central well of uniform cross section throughout, a hammer member of substantially the same cross-section as said well and guided therein, and a coil surrounding said member. I

In testimony whereof I aiiiX my signature.

HENRY PRELL.

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