Formation of three dimensional objects and assemblies

United States Patent m

Taylor et al.

tn]

[45]

US005348693A

Patent Number:
Date of Patent:

111

5,348,693 Sep. 20,1994

[54] [75]

[73]

[21] [22]

[51] [52]

[58]

[56]

FORMATION OF THREE DIMENSIONAL OBJECTS AND ASSEMBLIES

Inventors: Charles S. Taylor, San Francisco;

William B. Tiffany, Palo Alto; Paul
Cherkas, Saratoga; John J. Frantzen,
San Jose; Hilary J. Hampton, Santa
Clara; Leonard Nanis, Palo Alto;
Bhupendra O. Shah, Cupertino, all of
Calif.

Assignee: Advanced Cardiovascular Systems,
Inc., Santa Clara, Calif.

Appl. No.: 791,044

Filed: Not. 12,1991

Int. CI.s B29C 35/08; B29C 41/02

U.S. Q 264/22; 156/89;

156/155; 156/273.3; 156/273.5; 156/275.5; 156/307.1; 264/63; 264/132; 264/221; 264/255; 264/308; 264/317; 427/510; 427/555; 427/559

Field of Search 264/22, 125, 63, 132,

264/135, 221, 225, 255, 308, 317; 156/59, 62.2, 272.8, 155, 273.3, 273.5, 275.5, 307.1, 89; 427/510, 508, 553, 554, 555, 559; 29/604

References Cited U.S. PATENT DOCUMENTS 3,264,385 8/1966 Reed 264/132

3,390,447 7/1968 Mears 29/604

4,113,480 9/1978 Rivers 264/63

4,575,330 3/1986 Hull 264/22

4,698,907 10/1987 Soszek 29/846

4,752,352 6/1988 Feygin 156/59

4,863,538 9/1989 Deckard 264/125

5,059,266 10/1991 Yamane et al 264/22

5,088,047 2/1992 Bynum 156/62.2

5,094,935 3/1992 Vassiliou et al 156/59

5,156,697 10/1992 Bourell et al 156/62.2

Primary Examiner—Leo B. Tentoni

Attorney, Agent, or Firm—Crosby, Heafey, Roach &

May

[57] ABSTRACT

A method and system for making a three dimensional product wherein the size and shape of a plurality of cross-sectional segments of the three dimensional object are determined which when assembled together in a particular sequence form the desired three dimensional shape. Thin layers of material in the shape of each of the cross-sectional segments are applied in the particular sequence in which they form the three dimensional object. The application of each of the layers is much like a lithographic printing process in that a resin may be applied by a roller in the shape of the cross-sectional segments.

28 Claims, 2 Drawing Sheets

1

FORMATION OF THREE DIMENSIONAL
OBJECTS AND ASSEMBLIES

BACKGROUND OF THE INVENTION 5

This invention is directed to an improved method and system for forming multilayered, three dimensional objects and assemblies and the improved products formed thereby.

In the last few years significant efforts have been made to develop manufacturing and modeling systems based on computer assisted design (CAD) and computer assisted manufacturing (CAM). For example, a procedure and system is described in U.S. Pat. No. 4,575,330 (Hull) wherein a computer controlled beam of radiation is employed to cure a sequence of thin plastic layers of predetermined shape on a substrate disposed within a bath of radiation curable polymer resin. The particular shape and dimensions of the cured thin plastic 20 layers are controlled by controlling the application of the radiation by a suitably programmed computer to form the three dimensional object having the desired shape.

Another similar process and system for forming three 25 dimensional objects is described in U.S. Pat. No. 4,752,352 (Feygin) wherein a layer of powdered material is applied to a substrate and consolidated by pressure and then a computer controlled laser beam is applied to the surface of the layer of compressed powder 30 to sinter a portion thereof which is a cross-sectional segment of a three dimensional object.

In the same Feygin patent another method and system of forming a three dimensional object is described wherein the cross-sectional segments or layers of the 35 object are preformed individually, assembled into the desired three dimensional shape and then joined together by suitable means to form the final product.

In yet another method and system of forming three dimensional objects, which is offered by the Cubital 40 Corporation in Warren, Mich., a layer of curable plastic resin is applied to a substrate, an optical mask is positioned above the layer of plastic resin and radiation is directed through the clear or open portions of the mask to cure the layer of resin in a predetermined configura- 45 tion, the uncured resin is removed and then the cavities left by the removal of the uncured resin are filled by melted wax which is solidified by applying a cold flat plate thereto. Subsequent layers of plastic are then sequentially applied in the same manner to form the three 50 dimensional object. The wax is removed by heating or other suitable means. A computer creates the desired three dimensional shape of the desired object and then slices the shape into the shapes of the plurality of plastic layers which form the final shape. 55

A wide variety of other methods are described in the references listed below. The references listed are to be considered exemplary, not exhaustive on the subject.

U.S. Pat. No. 3,174,837 (Mears)

U.S. Pat. No. 3,390.447 (Mears) 60

U.S. Pat. No. 4,113,480 (Rivers)

U.S. Pat. No. 4,415,528 (Wiech)

U.S. Pat. No. 4,575,330 (Hull)

U.S. Pat. No. 4,698,907 (Soszek)

U.S. Pat. No. 4,710,253 (Soszek) 65

U.S. Pat. No. 4,740,410 (Muller, et al.)

U.S. Pat. No. 4,752,352 (Feygin)

U.S. Pat. No. 4,752,498 (Fudim)

2

U.S. Pat. No. 4,801,477 (Fudim)

U.S. Pat. No. 4,863,538 (Deckard)

U.S. Pat. No. 4,874,499 (Smith, et al.)

U.S. Pat. No. 4,915,757 (Rando)

U.S. Pat. No. 4,938,816 (Beaman, et al.)

U.S. Pat. No. 4,944,817 (Bourell, et al.)

While there has been much development in this area of technology, a need still exists for methods and systems to effectively form three dimensional products, particularly extremely small and complicated shapes such as are found in intravascular catheters and other devices which cannot be readily made by the prior methods. The present invention satisfies this need.

SUMMARY OF THE INVENTION

The present invention is directed to the method and system for making a three dimensional object by first developing the shapes and dimensions of a plurality of thin cross-sectional segments of the object which, when joined in proper sequence, form the desired size and shape of the three dimensional product and then forming the individual cross-sectional segments to form the three dimensional product.

The invention generally includes developing a plurality of planar cross-sectional segments, which when assembled and joined together in a prescribed sequence, form a three dimensional object or assembly of the desired size and shape. A plurality of sites are provided for forming the three dimensional objects. The number of formation sites are preferably at least equal to the number of different cross-sectional segments forming the three dimensional object or assembly. Individual layers of material are applied onto the formation sites in the shapes which have been previously developed for the individual cross-sectional segments of the three dimensional product and in the sequence in which they are joined together to develop the desired object or assembly. The layers should be of uniform thickness. The applied layers are consolidated and then, in a subsequent cycle, layers of material are applied in the shapes of the next cross-sectional segments in the appropriate sequence onto the consolidated layers at each of the formation sites. Preferably, in each cycle at least one desired three dimensional object or assembly is completed and at least one of such products is initiated. In each cycle all of the cross-sectional shapes may be applied simultaneously or sequentially.

In one presently preferred embodiment of the invention, the formation sites are arranged at locations so that a wedge or ramp of the cross-sectional segments is formed, extending from one location where only the first cross-sectional segment of the three dimensional object or assembly is formed, i.e. the formation of the desired three dimensional product begins, to a location where the last cross-sectional segment of the three dimensional object is applied, i.e. the formation of a desired three dimensional product is completed.

All of the individual cross-sectional segments need not be different. For example, products having some degree of symmetry may have one or more cross-sectional segments which are of the same size and shape. In this case, the number of formation sites need not be the same as the number of cross-sectional segments. Adjustments would have to be made in the sequencing of forming the layers to compensate. For example, in an idealized case where the sequence of three layers A, B and C is ABCBA, only three cross-sectional segments are used. The layers ABC are applied repetitively but