US3149596A

US3149596A - Forming apparatus

Info

Publication number: US3149596A
Application number: US116860A
Authority: US
Inventors: Vlieg Donald Gerard De; Christian Earl Landon
Original assignee: General Dynamics Corp
Current assignee: General Dynamics Corp
Priority date: 1961-06-13
Filing date: 1961-06-13
Publication date: 1964-09-22
Anticipated expiration: 1981-09-22

Description

P 22, 19164 D. G. DE VLIEG ETAL 3,149,596

FORMING APPARATUS Filed June 13, 1961 2 Sheets-Sheet 2 F IG. 3

INVENTORS DONALD G. DEVLIEG EARL L. CHRISTIAN 3'1 RNEY AGENT United States Patent 3,149,596 FQRMING APPARATUS Donald Gerard De Vlieg, La Mesa, and Earl Landon Christian, 31in Diego, Calif, assignors to General Dynamics Corporation, San Diego, (Ialifl, a corporation of Delaware Filed June 13, 1961, Ser. No. 116,860 2 Claims. ((15. 11344) This invention relates generally to forming apparatus and more particularly to forming apparatus capable of forming sheet metal blanks by the application of pressure to the blanks.

It is an object of the present invention to provide novel apparatus capable of forming blanks rapidly and accurately.

It is another object of the invention to provide novel apparauts which generates pressure to accurately form blanks.

It is a further object of the invention to provide novel apparatus which generates pressure having uniform distribution to form blanks.

It is still a further object of the invention to provide novel apparatus which generates pressure having uniform distribution and applies the pressure directly to blanks to be formed.

It is another object of the invention to provide novel forming apparatus which forms blanks with very little material thinning of the formed part.

Other objects, advantages and capabilities of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a pictorial view in perspective of the forming apparatus arranged for use with a blow imparting device.

FIGURE 2 is a vertical central section through the forming apparatus, showing the movable die separated from the stationary die and carrying the sheet metal blank to be formed and the draw ring.

FIGURE 3 is the same as FIGURE 2, except that the movable die and the parts carried thereby have been inserted in the stationary die such that they rest upon the deformable material in the stationary die.

FIGURE 4 is the same as FIGURES 2 and 3 with the forming of the sheet metal blank completed; and

FIGURE 5 is a perspective view of the sheet metal blank in its formed state such as may be produced in the practice of this invention.

Similar reference numerals refer to like parts throughout the several views.

Referring to the drawings, and particularly to FIG- URES 1 and 2, the forming apparatus of the present invention is generally indicated by the numeral 8 and consists of a stationary die 10 adapted to be positioned on a base member 11, and a movable die 12 adapted to face the force imparting member 13 of a high energy actuator, for example, of the type revealed in Patent No. 2,979,938 and issued to Jack B. Ottestad.

The stationary die 10 is generally outwardly cylindrical in shape and has an aperture 14 also generally cylindrical in shape with a bottom 16 and mouth 18. A fluid passage 20 is provided in the stationary die member for interconnecting the aperture with the outside of the die member, and is located intermediate the bottom 16 and mouth 18. A deformable material 22, which has perfect fluidity, prefably a liquid, such as water, is positioned in the aperture 14, and has a level 23 just below the fluid passage 20.

The movable die 12 has an outer surface configuration conforming to the shape of the aperture 14 as to provide a close slip-fit between it and the stationary die member when inserted in the aperture, as shown, for example, in

"ice

FIGURES l and 2. An annular seal 24 positioned in a suitable groove in the outer surface of the movable die 12 provides sealing between the dies. The movable die has a workingsurface which comprises a cavity 26 and a flat portion 28 surrounding the cavity. The cavity 26 is shown as being hemispherical in shape for illustration purposes, but it is to be understood that it could assume any desired shape to be imparted to a blank to be formed. To provide for the escape of air from the cavity 26 during the forming operation, a fluid passage 30 in the movable die 12 interconnects the cavity with a plurality of radial grooves 31 in the upper surface of the movable dies.

A sheet metal blank 32 is adheringly positioned on the flat portion 28 of the movable die 12 as to cover the cavity by means of a film 34 of heavy lubricator material, such as grease, or the like. Another film 36 of like lubricator material adheres a plate member or draw ring 38 to the blank 32 such that an orifice 40 in the draw ring exposes the portion of the blank 32 covering the cavity 26. The draw ring 38 conforms to the shape of the aperture 14, as to be insertable therein along with the movable die 12 and blank 32, as shown in FIGURE 3. The film 34, in addition to adhering the blank 32 to the movable die 12, also provides lubrication and sealing therebetween during the forming operation, as will hereinafter be more fully described. In like manner the film 36 also provides lubrication between the blank and the plate member 38.

In the operation of the device of the present invention, the movable die 12 carrying the blank 32 and plate member 38 is inserted into the aperture 14 and allowed to settle into and float on the liquid 22. As the movable die travels into the aperture first air, and then excess water is expelled through the fluid passage 20. .When water ceases to flow through the fluid passage 20, the parts are positioned as shown inFIGURE 3.

Referring to FIGURE 4, when a blow is applied to the movable member 12 by the member 13, the movable die and its associated parts are further forced into the liquid 22 to produce a uniformly distributed hydraulic pressure which acts on the blank directly through the orifice 40 to force it into the cavity 26 wherein it assumes the shape of the cavity, as shown in FIGURES 4 and 5. During this rapid forming action, pressure is maintained on the draw ring 38 which prevents the edge of the blank 32 from wrinkling as it is drawn into the cavity 26, and also prevents the edge from bending and allowing water to be forced between the blank and the draw ring into the cavity.

The

films

34 and 36 greatly aid the forming action by facilitating the sliding of the blank 32 between the movable die 12 and the draw ring 38 as it is drawn into the cavity 26, which results in very little material thinning of the formed part. The film 34 also establishes a seal between the blank and the movable member, thus preventing the Water 22 from entering the cavity 26, which would result in a malformed part. Any back pressure which would be developed by air trapped in the cavity 26 as the blank is forced into the cavity is allowed to bleed ofr through the fluid passage 30 and radial grooves 31, thus also insuring a properly formed part.

Although a specific embodiment of the invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only; it is to be understood that the invention is not limited thereto, as many variations will be readily apparent to those versed in the art and the invention is to be given its broadest possible interpretation within the terms of the appended claims.

What is claimed is:

1. Forming apparatus comprising a first member having an aperture, fluid passage means interconnecting said aperture with the outside of said first member, said fluid passage means being located intermediate the mouth and bottom of said aperture, a plate member having an orifice, a second member having a cavity, said second member conforming to said aperture and having a close slipfit therebetween, means for venting said cavity, and means for adhering said plate member and a blank to be formed on said second member to cover said cavity and expose a portion of the blank through said orifice, said plate memher and second member being positionable within said aperture and supportable on a liquid in said aperture to contact the blank portion with the liquid through said orifice, said first and second members being relatively movable for urging the liquid through said orifice to force the blank into said cavity to assume the shape of said cavity.

2. Forming apparatus comprising a stationary die mem her having an aperture,'fluid passage means interconnecting said aperture with the outside of said stationary die member, said fiuid passage means being located intermediate the mouth and bottom of said aperture, a plate member having an orifice, a movable die member having a cavity, said movable die member conforming in close slip-ifi-t With said aperture means for venting said cavity, a first film of lubricator material for adhering a blank to be formed on said movable die member to cover said cavity, a second film of lubricator material for adhering said plate member to the blank to expose the portion of the blank covering said cavity through said orifice, said plate member and movable die member being positionable within said aperture and supportable on a liquid in said aperture to contact the blank portion with the liquid through said cavity, said movable die member being movable into said aperture for urging the liquid through said orifice to force the blank into said cavity to assume the shape of said cavity.

References Cited in the file of this patent UNITED STATES PATENTS 696,821 Huber Apr. 1, 1902 2,199,627 French et al. May 7, 1940 2,284,773 Sivian et al. June 2, 1942 2,354,005 Flowers July 18, 1944 2,649,067 Kranenberg Aug. 18, 1953 2,969,758 HoWlett et al Jan. 31, 1961 FQREIGN PATENTS 603,683 Great Britain June 21, 1948 650,747 Great Britain Feb. 28, 1951

Claims

1. FORMING APPARATUS COMPRISING A FIRST MEMBER HAVING AN APERTURE, FLUID PASSAGE MEANS INTERCONNECTING SAID APERTURE WITH THE OUTSIDE OF SAID FIRST MEMBER, SAID FLUID PASSAGE MEANS BEING LOCATED INTERMEDIATE THE MOUTH AND BOTTOM OF SAID APERTURE, A PLATE MEMBER HAVING AN ORIFICE, A SECOND MEMBER HAVING A CAVITY, SAID SECOND MEMBER CONFORMING TO SAID APERTURE AND HAVING A CLOSE SLIPFIT THEREBETWEEN, MEANS FOR VENTING SAID CAVITY, AND MEANS FOR ADHERING SAID PLATE MEMBER AND A BLANK TO BE FORMED ON SAID SECOND MEMBER TO COVER SAID CAVITY AND EXPOSE A PORTION OF THE BLANK THROUGH SAID ORIFICE, SAID PLATE MEMBER AND SECOND MEMBER BEING POSITIONABLE WITHIN SAID APERTURE AND SUPPORTABLE ON A LIQUID IN SAID APERTURE TO CONTACT THE BLANK PORTION WITH THE LIQUID THROUGH SAID ORIFICE, SAID FIRST AND SECOND MEMBERS BEING RELATIVELY MOVABLE FOR URGING THE LIQUID THROUGH SAID ORIFICE TO FORCE THE BLANK INTO SAID CAVITY TO ASSUME THE SHAPE OF SAID CAVITY.