US2591083A

US2591083A - Removal of flash, fin, and burr

Info

Publication number: US2591083A
Application number: US732311A
Authority: US
Inventors: Herbert N Maier
Original assignee: DOEHLER JARVIS CORP
Current assignee: DOEHLER JARVIS CORP; DOEHLER-JARVIS Corp
Priority date: 1947-03-04
Filing date: 1947-03-04
Publication date: 1952-04-01
Anticipated expiration: 1969-04-01

Description

April 1, 1952 H. N. MAIER REMOVALOF FLASH, FIN, Amp BURR Filed March 4, 1947 FIG 2 38 TO SUPER SONIC AC SOURCE FIG I TO SONIC AC SOURCE FIG 3 POWER SOURCE INVENTOR HERBERT N. MAI

BY Z

ATTORNEY Patented Apr. 1, 1952 REMOVAL OF FLASH, FIN, AND BURR Herbert N. Meier, Pottstown, Pa., assignor to Doehler-Jarvis Corporation, New York, N. Y., a

corporation of Michigan Application March 4, 1947, Serial No. 732,311

Claims.

This invention relates to the finishing of shaped bodies, and more particularly to the removal of flash, fin, safety edge, or/and burr therefrom.

Flash or fin is left on a metal casting at the parting face of the mold, and at the ends of the ejector pins, particularly as the mold begins to Wear. Even after the hash or fin is removed, a feather edge or burr may remain. In die-casting practice, a so-called safety edge or overflow is sometimes purposely provided to protect a corner edge of the casting, or to facilitate subsequent breaking-off of the overflow. Here again the safety edge must be removed, and even then a burr is usually left after removal of the safety edge. Burr is not limited, however, to castings, and instead may be found on metal parts which have been subjected to stamping, coining, or forging operations, and machining operations such as drilling and tapping. Moreover, the problem is not limited to metal objects, for fiash or fin is produced when molding plastics.

Heretofore, various methods have been employed to remove flash, fin, or safety edge. Sometimes a trimming die is employed. For very heavy flash a band-saw may be used. For a small, light flash, tumbling has been employed. Hand operations are often resorted to, including the use of a mallet, a bending fixture, and files. For the removal of burrs, it has been the practice to employ hand-filing, grinding wheels, de-burring Wheels, belt sanders, and tumbling. All of the methods heretofore used have required considerable time and labor.

The primary object of the present invention is to provide a new, rapid, and relatively inexpensive method for removing iin, safety edge, and burr. In accordance with the new method, the objects are immersed in a liquid, and the liquid is vibrated at a relatively high frequency, preferably a sonic frequency, although a super sonic frequency may also be used.

To accomplish the foregoing general object, and other more specific objects which will hereinafter appear, my invention resides in the meth 0d and apparatus elements and their relation one to the other, as are hereinafter more particularly described in the following specification. The specification is accompanied by a drawing in which:

Fig. 1 schematically illustrates a form of the invention using a magnetic diaphragm;

Fig. 2 schematically illustrates a modification using a magnetostriction eifect;

Fig. 3 shows a modification in which two diaphragms are vibrated in opposed phase; and

Fig. 4 is explanatory of a detail of the invention.

Referring to the drawing, and more particularly to Fig. 1, the apparatus comprises a container 12 for a body of liquid M. The: container may be made substantially higher than the liquid level, or in the alternative, a removable cover It may be employed, as shown. The apparatus further includes means it to support a plurality of objects 23 in the liquid Hi. There is also a means 22 to vibrate the liquid it at a relatively high frequency. In the present case, the liquid is vibrated at a sonic frequency by a diaphragm which acts as the bottom wall of the container. The support I8 is a highly perforate basket. The diaphragm 22 is vibrated by means of an electromagnet 24, the said diaphragm forming a part of a magnetic circuit 25 having an air gap at 28. The magnet coil is connected to a suitable source of sonic frequency A. C. power.

A modification of the vibrator portion of the apparatus is schematically shown in Fig. 2. This differs from Fig. l primarily in using a metal rod 30 fixedly connected between the housing 32 and the diaphragm 34. The diaphragm is vibrated by magnetostrictive elongation and contraction of the rod 36 in response to an alternating magnetic field applied thereto by the coil 3%. The conductors 38 are connected to a sonic or a supersonic frequency source of power.

For the present purpose, multiple objects should be placed in mutual contact in the liquid, for the flash, fin or burr is removed by the abrasion 01' rubbing of one object against the other. This is indicated schematically in Fig. l, in which many objects 2!} are employed to largely fill the basket or support it. When the objects are small, they may be vibrated in direct contact with one another. When the articles are large, or of some unusual shape, it may be preferred to supplement them with additional objects which act fundamentally as fillers. This is schematically illustrated in Fig. 4, in which the cage or support 43 contains a limited number of objects 42 the spaces between which are filled with small auxiliary objects or fillers 44.

In effect, the water or other liquid in the tank acts merely as a means to transfer the vibration from the diaphragm to the articles. For this purpose, oil may be used instead of water, and in fact, in some respects may be better than Water, but in most manufacturing processes oil would have the disadvantage of requiring a separate clegreasing operation which would. not be needed when using plain water.

The desired de-burring action may be ob- 3 tained by burying the objects in a dry medium such' as fine sand. However, it is vastly more convenient to lower the objects into a body of liquid than to bury them in a dry mixture or sand, and the same applies to the subsequent removal of the objects.

With apparatus of the character here shown, de-burring was as effective in one or two minutes as the older practice of tumbling would have been in, say, a half-hour.

Referring now to Fig. 3, the container there shown carries a body of liquid 52 in which objects 54 to be treated are supported by a suitable perforate or grid-like support 56. In this case the container is provided with two spaced vibratile diaphragms 58 and 69, which contact the liquid 52. The diaphragms are vibrated by suitable vibrator units 62 and 64, respectively. These are energized from a power source 66, and are so wired to the source as to be vibrated in synchronism but in phase opposition. Thus the diaphragm 58 will advance or push when diaphragm 60 retracts or pulls. This efficiently sets the body of liquid into vibration. The

diaphragms

58 and 60 may form a part of the wall of the container, as here shown. It is sufficient that they be spaced well apart, as for example, on the bottom wall, but it is preferable that they form parts of opposed walls of the container, as here shown.

Either a sonic or supersonic frequency of vibration may be employed. In general, it is simpler and easier to produce a sonic frequency vibration, for it is not essential in that case to employ vacuum tube oscillators and amplifiers, etc., although they may be used. On the other hand, a supersonic vibration has the advantage of avoiding the loud and disturbing noise produced by sonic equipment. Even in the case of supersonic vibration, however, care must be taken not to employ a frequency which may adversely affect personnel working around the equipment.

It will be understood that the vibration of the diaphragm may be produced in any of the known or conventional ways. The vibration of the diaphragm may be produced by mechanical means. The diaphragm may be vibrated by direct magnetic effect. It may also be vibrated by the use of a coil movably mounted in a suitable magnetic field, for example, a D. C. field, the coil carrying an excitation current, for example, a pulsating or an A. C. current. This would be analogous to the operation of a so-called dynamic loud speaker. The diaphragm may also be vibrated by magnetotriction of a ferrous or nickle alloy or other magnetostrictive rod, or by the use of a piezo crystal, for example, a quartz or a Rochelle salt crystal. The alternating current may be obtained in any conventional apparatus, such as a vacuum tube oscillator, or a frequency multiplier, or a motordriven generator. A variable frequency source may be employed if it is desired to vary the frequency in accordance with the size of the objects being treated, or the hardness or the mass of the metal or plastic being treated.

The vibration may be obtained by using pulsating D. 0. power, instead of A. C. power. Thus for magnetic striction it is sufficient that the magnetic field build up and collapse at the desired frequency, the polarization of the field being unimportant.

It will be understood that vibration may be produced in ways other than those specifically illustrated.

Spaced diaphragms may be used in a single tank without operating them in push-pull. Thus multiple diaphragms may be disposed in a single wall, and all be operated in unison, or several spaced diaphragms may be operated with a difference in phase, but without necessarily being in phase opposition.

Moreover, basically it is not even essential that there be a flexible diaphragm in an otherwise rigid wall. In theory, the entire tank may be vibrated, or in contrast with that, a vibratile diaphragm with its driver may be suspended in the liquid, without touching or forming a part of the tank wall, in which case the tank wall need not be vibrated at all. However, it is believed that in every case it may be said that there is some form of mechanical network which is set into vibration as an entirety.

The elementary explanation that the dia-- phragm vibrates the liquid and the objects in contact with each other may be too simplified. In an assembly of this sort, the volume and weight of the liquid and objects usually go to form the mechanical equivalent of an impedance matching network which loads the entire system, keeping it in resonance with the excitation frequency.

It will be understood that the article, objects and liquid are relatively vibrated, and it is not essential that the vibration be initially applied to the liquid per se to produce such relative vibration.

It is believed that the method of the present invention, as well as the nature of the apparatus which may be employed to practice the method, and the advantages thereof, will be apparent from the foregoin detailed description. It will also be apparent that while I have shown and described my invention in several preferred forms,

changes may be made in the method and apparatus disclosed, without departing from the spirit of the invention as sought to be defined in the following claims. In the claims the reference to placing a plurality of objects in the liquid is intended to include a plurality of the articles being treated, or one such article and a plurality of fillers, or a plurality of articles and a plurality of fillers. The reference to removal of flash, fin, or burr is intended also to include the removal of the safety edge itself.

I claim:

1. The method of removing flash, fin, or burr from objects, which includes placing a plurality of objects in propinquity in a. liquid, and so vibrating said liquid at a relatively high frequency as to cause mutual vibratory contact between said objects.

2. The method of removing flash, fin, or burr from objects, which includes placing a plurality of contacting and relatively movable objects in a liquid, and vibrating said liquid at a sonic frequency in order to cause mutual vibratory contact between said objects.

3. The method of removin flash, fin, or burr from objects, which includes placing a plurality of contacting and relatively movable objects in a liquid, and vibrating said liquid at a supersonic frequency in order to cause mutual vibratory contact between said objects.

4. Apparatus for removing flash, fin, or/and burr from objects, said apparatus comprising a stationary container for a body of liquid, two spaced vibratile diaphragms contacting said liquid, means to vibrate one of said diaphragms, and means to vibrate the other diaphragm at the same frequency but with a difference in phase relative to the first diaphragm.

5. Apparatus for removing flash, fin, or/and burr from objects, said apparatus comprising a a part of each of two oppositely disposed walls of said container being a vibratile diaphragm,

means to vibrate one of said diaphragms, means to vibrate the other diaphragm at the same frequency but opposed phase relative to the first diaphragm.

6. Apparatus for removing flash, fin, or/and burr from objects, said apparatus comprisinga stationary container fora body of liquid, means for supporting a plurality of objects in the body of liquid, the walls of said container including two spaced vibratile diaphragms, means to vibrate one of said diaphragms, means to vibrate the other diaphragm at the same frequency but opposed phase relative to the first diaphragm.

7. Apparatus for removing flash, fin, or/and burr from objects, said apparatus comprising a stationary container for a body of liquid, means for supporting a plurality of objects in contact in the body of liquid, at least a part of each of two oppositely disposed walls of said container being a vibratile diaphragm, means to vibrate one of said diaphragms, means to vibrate the other diaphragm at the same frequency but opposed phase relative to the first diaphragm, said diaphragms being vibrated by said means at a fre- ,quency in the range of sonic and supersonic frequencies.

8. Apparatus for removing flash, fin, or/and burr from objects, said apparatus comprising a stationary container for a body of liquid, means for supporting a plurality of objects in propinquity in said body of liquid, the walls of said container including two spaced vibratile diaphragms, means to vibrate one of said diaphragms, and means to vibrate the other diaphragm at the 6 same frequency, but with a difference in phase relative to the first diaphragm.

9. The method of removing flash, fin, or burr-from a molded article, which includes placing the article together with large filler objects in propinquity in a liquid, and so relatively vibrating at high frequency the article and liquid and filler objects as to cause mutual vibratory contact between the article and the objects, said high frequency being in the range of sonic and supersonic frequencies.

10. The method of removing flash, fin, or burr from molded objects, which includes placing a plurality of the molded objects in propinquity in a liquid, and so relatively vibrating said objects and liquid at high frequency as to cause mutual vibratory contact between said objects, said high frequency being in the range of sonic and supersonic frequencies.

HERBERT N. MAIER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 149,534 Smith Apr. 7, 1874 1,304,810 Sawyer May 27, 1919 2,402,967 Lubenow July 2, 1946 2,427,348 Bond et al. Sept. 16, 1947 2,460,918 Bodine Feb. 8, 1949 2,468,550 Fruth 1 Apr. 26, 1949 FOREIGN PATENTS Number Country Date 548,960 Great Britain Oct. 30, 1942