US3154621A - Heat treating apparatus - Google Patents

Description

Oct. 27, 1964 c. F. ALBAN 3,154,621

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United States Patent 3,154,621 HEAT TREATING APPARATUS Clarence F. Alban, Allen Park, Mich, assignor, by mesne assignments, to W. M. Chase Company, a corporation of Delaware Filed Apr. 18, 1961, Ser. No. 103,915 1 Claim. (Cl. 2665) This invention relates to heat treating apparatus, and more particularly to a furnace for heat treating a continuous flow of parts.

It is an object of the present invention to provide an improved treating mechanism which is capable of continuously feeding and heating a wide variety of objects.

Another object is to provide an improved heat treating furnace which is economical to manufacture, operate and maintain.

The present invention acomplishes the above objects by providing a furnace chamber adapted to enclose a spiral ramp elevator of a vertical vibratory feeder operative to feed objects vertically through the furnace chamher so that a continuous flow of the objects may be heated therein while being transported therethrough.

In the accompanying drawing:

FIG. 1 is an elevational view of a heat treating furnace constructed in accordance with the present invention, with the furnace shown in the open position thereof and taken partially in section on the line 1-1 of FIG. 2; and

FIG. 2 is a top plan view of the heat treating furnace of FIG. 1 illustrating the open and closed positions thereof.

Referring to FIG. 1, the heat treating apparatus of the invention includes a vibratory feeding mechanism 1%) of known construction, such as the vertical-vibratory spiral feeders of either the ES or RVES model series manufactured by Syntron Company of Homer City, Pennsyl- Vania. By way of illustration, the disclosed form of vibratory feeder includes a vibrator drive mechanism 16 which is mounted upright by means of a suitable shock absorbing cushion 13 on a support 20. A vertical column 22 is mounted on the top of vibrator 16 for supporting a ramp 24 wound helically therearound. The above vertical vibratory spiral feeder can be supplied with two different forms of known drives, either electromagnetic or rotary vibratory. Vibratory 16 is shown as the electromagnetic type of drive unit and is electrically powered for producing high speed electro-magnetic vibrations (3600 vibrations per minute) which are transmitted via column 22 to ramp 24, the vibrational motion of ramp 24 causing objects received on the surface of the ramp to flow up the ramp. This type of vibratory feeder is available with rheostat or reactor controls for controlling the rate of elevation or flow of material in the ramp. Such controls may be incorporated in a suitable control box 26 (shown only in FIG. 1) and connected by leads 23 to the vibrator mechanism 16. Vibrator 16 may also comprise a slower speed rotary vibrator type of drive unit when it is desired to handle larger, higher spirals at greater capacities than is possible with the electromagnetic type. With the rotary type, the control of the rate of material how and adaptability to dilferent materials is accomplished by adjusting the thrust angle of the rotary vibrator.

The present invention combines the above conventional vertical vibratory feeder it with a furnace 12 to provide an improved heat treating apparatus. One half of furnace 12 includes a semi-cylindrical outer casing 3% which is closed at the ends thereof and supported independently of the feeding mechanism by legs 32 so as to be isolated from the vibratory motion thereof. Disposed concentrically within outer casing 30 is a semi-cylindrical inner casing 34 which is made of heat resistant metal or suitable refractory material, depending upon the temperature ranges to be used in the heat treatment. An insulating lining 36, also made of suitable heat resistant material, is provided between outer and inner casings 30 and 34. A semi-cylindrical door strpcture 38 forms the other half of furnace l2 and comprises outer and inner casings 4t) and 42, respectively identical in shape to casings 30 and 34, as well as a refractory lining 44 located between casings 3t} and 34. Door 38 is pivotably connected to outer casing 3t) along one vertical side edge thereof by three hinges 4s. Semi-circular openings 48 and 50 are provided in the respective bottom portions of the fixed casings 3t 34 and the door 33 so that when door 38 is swung to its closed position (indicated in dashed lines in FIG. 2) a circular center hole is provided for receiving column 22. Each of the furnace openings 48 and St) has a semi-cylindrical liner 51 affixed thereto which is made of suitable soft, heat resistant material to provide an insulating seal between column 22 and the furnace openings which neither transmits nor restricts the vibratory motion of the column.

When furnace 12 is closed, complemental inner casings 32 and 42 form an annular heating chamber 52 concentrically surrounding and completely enclosing spiral ramp 24. Chamber 52 is heated by suitable heat generating means such as a co-axial series of electrical heating element coils 54 suspended on a stringer conduit 55 adjacent the inner surfaces of casings 34 and 42. Heating element 54 is energized via leads enclosed in conduit 55 which are coupled through control box 26 to a suitable source of electrical power. A fan 58 is suspended in the fixed half of furnace 12 near the top of chamber 52 by a shaft ea journalled in the top ends of casings 30 and 34. Fan shaft 60 is driven by an electric motor 62 which is energized via leads 64 also coupled through control box 26 to the source of power.

A gravity input chute 66 is mounted in and extends through an opening in the furnace wall to feed objects such as small metal parts from outside the furnace into a receiving hopper d3 supported on column 22 inside the furnace chamber. An inclined discharge chute 70 is supported with its upper end beneath the upper, outlet end 25 of ramp 24 so as to receive parts discharged therefrom. Chute '74) also extends through an opening in the wall of the furnace and delivers the parts by gravity to a hopper or conveying apparatus, not shown.

In operation, the furnace is closed and then heating element 54 is energized automatically by suitable thermostatic controls located in control box 26 and connected in a known manner to provide automatic temperature control. Motor 62 is also energized whereupon fan 58 blows heated air downwardly along the spiral ramp 24 in a direction opposite to the flow of parts therein. The circulating air is reheated as it returns upwardly along the coils of heating element 54. Vibrator 16 of the feeder is then automatically or manually energized to cause vibratory motion of spiral ramp 24, and objects such as small metal parts are fed via chute 66 to hopper 68. The vibratory motion of ramp 24 causes the parts to climb up the ramp, the parts being heated to a desired temperature for a desired period of time in accordance with the controllable rate of feed of the feeder mechanism and the controllable air temperature within chamber 52. As the heated parts reach upper end 25 of ramp 2d they drop into discharge chute 70 and are delivered via gravity to the exterior of the furnace.

The above described heat treating apparatus permits a rapid, continuous stream of parts to be heat treated without interruption of their travel to and from chutes 66 and 7t). By utilizing a vertical vibratory feeder combined with a concentrically enclosing furnace chamber,

a compact arrangement is obtained which occupies a minimum of fioor space. Inasmuch as the parts are conveyed entirely by ramp 24 and chutes 66 and 70, there are no working mechanical parts, such as motors, gears, sprockets, chains, buckets, speed changers or the like to be adversely afiected by the heat of the furnace. The flow of parts in the ramp can be stopped, blocked or choked without any damage to the equipment, and the provision of the hinged door 38 allows immediate access to the entire ramp so that such stoppages may be easily cleared. Because of the large surface area of the spiral ramp contained within the relatively small concentric heating chamber 52, economic and efiicient heating of the parts can be accomplished by radiation as well as by the reverse air flow created by fan 58.

It is to be understood that it is within the scope of the present invention to utilize a suspension mounting of the vertical vibratory feeder wherein a vertical spiral ramp enters the furnace from the top thereof rather than at the bottom as disclosed. Moreover, the flow of parts may be reversed so that they are lowered by the spiral ramp during their passage through the furnace chamber, and likewise the flow of air may be directed in either direction along the spiral ramp by merely reversing motor 62.

I claim:

Apparatus for continuously heat treating small metal parts comprising a fixed casing having insulated top, bottom and upright side walls defining an oven chamber therein, a vibratory feeder mechanism supported independently of said casing including a vibrator positioned outside said casing and a column extending vertically therefrom into said oven chamber, said casing having an opening in one of said top and bottom walls adapted to receive said column therethrough, insulating means interposed in said opening between said column and said casing for heat scaling said opening, a helical ramp supported on said column entirely within said chamber and having an inlet and an outlet spaced vertically from one another therein, electrical heating means including a series of heating elements positioned between said helical ramp and said side wall of said casing and at least partially surrounding substantially the entire length of said ramp, said side wall of said casing including a door section hinged thereto for lateral swinging movement about a vertical axis, said door having a horizontal dimension larger than the diameter of said ramp to facilitate access to and installation of said ramp in said chamber, and means extending through said side wall of said casing for delivering the parts to the inlet and from the outlet of said ramp whereby objects are heat treated while being transported on said ramp in response to operation of said vibrator and said heating means.

References Cited in the file of this patent UNITED STATES PATENTS 1,043,158 Simmons Nov. 5, 1912 1,073,912 Koch Sept. 23, 1913 2,283,798 Delano May 19, 1942 2,557,379 Hancock et al June 19, 1951 2,615,702 Allert Oct. 28, 1952 2,658,286 Spurlin Nov. 10, 1953 2,662,851 Jones et al Dec. 15, 1953 2,688,807 Ginther Sept. 14, 1954 2,918,070 Carrier Dec. 2, 1959 2,965,368 Mcllvried Dec. 20, 1960 3,032,409 Richelson May 1, 1962

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