Animal cage and method for making same

• US 6,293,227 B1
• Filed: 11/07/1999
• Issued: 09/25/2001
• Est. Priority Date: 11/07/1999
• Status: Expired due to Term

• Current Assignee: Varis Corporation
• Original Assignee: Varis Corporation
• Inventors: Ver Hage, Richard P.
• Primary Examiner(s): PRICE JR, RICHARD THOMAS
• Application Number:
  US09/436,924
• Time in Patent Office: 688 Days
• Field of Search: 119/165, 119/166, 119/167, 119/168, 119/169, 119/170, 119/417
• US Class Current: 119/417
• CPC Class Codes: A01K 1/031 Cages for laboratory animals; Cages for measuring metabolism of animals

Abstract

An improved mold releasing technique including use of moveable segments to form a part of the male portion of the mold, and the unique product formed thereby is described. The moveable segments which disengage from integral contact with the product once it is formed, permit the formation of the uniquely formed product which includes side and end walls which can be less than 1 degree off vertical. This enables the manipulation of the product design parameters including each wall angle at various points along the wall to achieve a desired wall surface profile especially in the vicinity of the product floor. This results in an increased surface area at or near the product floor which permits a greater number of animals to be housed in the cage product in accordance with Federal guidelines. The tailoring of the wall profiles also allow for the nesting of the products and the accommodation of prior art covers and accessories.

Claims

1. An improved animal cage product having a desired internal surface profile, produceable in cost-effective, production quantities and configured to receive a prior art lid and/or accessories, comprising:

(a) a cage floor disposed in a first plane;

(b) first and second end walls, each said end wall oppositely disposed from each other and including a bottom edge and a top edge and having an interior surface and an exterior surface;

(c) first and second side walls, each said side wall oppositely disposed from each other and including a bottom edge and a top edge and having an interior surface and an exterior surface;

(d) a first curved wall segment and a second curved wall segment, connected respectively between said cage floor and said bottom edge of said first and second end walls;

(e) a third curved wall segment and a fourth curved wall segment, connected respectively between said cage floor and said bottom edge of said first and second side walls;

said first, second third and fourth curved wall segments having an interior radius of curvature of a first, predetermined dimension and an exterior radius of curvature of a second, predetermined dimension,

the interior surface of each said end wall and said side wall extending upward a first predetermined distance from the first plane at a first predetermined angle off vertical and continuing above said first predetermined distance for at least a portion of the distance remaining to the top edge of the respective wall at a second predetermined angle off vertical, whereby the square area of an imaginary surface at a prescribed distance above the plane of said cage floor and parallel to said plane meets or exceeds a standard—

set, figure, and whereby one such cage product can be removeably nested in the top opening of a second such cage product,

said improved animal cage product formed by a molding process wherein a suitable plastic material is molded to a final configuration in a mold having a male portion and a female portion, said animal cage product formed between said male portion and said female portion, said male portion including a mechanical mold release means, said mechanical mold release means including,

(f) a first fixed segment;

(g) and at least a first moveable, knockout segment having an outer surface including a knockout contact surface and a wall forming surface, said at least said first moveable, knockout segment moveable from a first position to a second position in relation to said first fixed segment after the molding of the animal cage product;

wherein said at least said first moveable segment when in said first position collectively forms with said first fixed segment, said male portion of the mold, said collectively formed male portion of the mold having a substantially integral outer surface configuration dimensioned substantially equivalently to the desired internal surface profile of said formed cage product and about which said cage product is formed together with said female portion, said wall forming surface, when said moveable knockout segment is in said first position, disposed in contact with a substantial portion of the interior surface of at least one of said walls between its respective bottom edge and its top edge; and

,

(h) means for moving said at least said first moveable, knockout segment from said first position to said second position, whereby as said at least said first moveable segment moves from said first position to said second position, said wall forming surface is disengaged from integral contact with the interior surface of said corresponding formed wall of said formed cage product immediately upon initiation of movement of said at least said first moveable segment from said first position,

and wherein said knockout contact surface of said at least said first moveable, knockout segment remains in contact with the formed cage product as it moves from said first position to said second position, whereby the formed product is readily separated and thereafter easily removed from the mold.

2. The improved animal cage product claimed in claim 1 having:

a first and second moveable, knockout segment,

said first moveable knockout segment having an outer surface including a first knockout contact surface and a first wall forming surface, said first moveable, knockout segment moveable from a first position to a second position in relation to said first fixed segment after the molding of the animal cage product;

said second moveable, knockout segment having an outer surface including a second knockout contact surface and a second wall forming surface, said second moveable, knockout segment moveable from a first position to a second position in relation to said first fixed segment after the molding of the animal cage product;

wherein said first and second moveable segments when in said first position collectively form with said first fixed segment, said male portion of the mold, said collectively formed male portion of the mold having a substantially integral outer surface configuration dimensioned substantially equivalently to the desired internal surface profile of said formed cage product and about which said cage product is formed together with said female portion,

said first and second wall forming surfaces, when said first and second moveable knockout segments are in said first position, each disposed in contact with a substantial portion of the interior surface of a respective wall between its respective bottom edge and its top edge; and

,

(i) means for moving said first and second moveable, knockout segments from said first position to said second position, whereby as said first and second moveable segments move from said first position to said second position, each said respective wall forming surface is disengaged from integral contact with the interior surface of said corresponding formed wall of said formed cage product immediately upon initiation of movement of said first and second moveable segments from said first position,

and wherein said first and second knockout contact surface of said first and second, moveable knockout segments remains in contact with the formed cage product as it moves from said first position to said second position, whereby the formed product is readily separated and thereafter easily removed from the mold.

3. The improved animal cage product claimed in claim 2 wherein said means for moving each said moveable, knockout segment include each said moveable, knockout segment having a cam portion and a cam follower portion, said first fixed segment including a respective cam follower surface for coacting with each said cam follower, whereby as each said moveable, knockout segment moves from said first position to said second position, each said cam follower tracks its respective cam follower surface such that each said moveable, knockout segment is disengaged from integral contact with the interior surface of said formed cage product whereby the formed product can be readily removed from the mold.

4. The animal cage product claimed in claim 2 wherein said first predetermined angle is about one degree off vertical and said second predetermined angle is about two degrees off vertical.

5. The animal cage product claimed in claim 2 wherein said first predetermined distance is approximately 1 and {fraction (1/16)} inches.

6. The improved animal cage product claimed in claim 1 wherein said means for moving each said moveable, knockout segment include each said moveable, knockout segment having a cam portion and a cam follower portion, said first fixed segment including a respective cam follower surface for coacting with each said cam follower, whereby as each said moveable, knockout segment moves from said first position to said second position, each said cam follower tracks its respective cam follower surface such that each said moveable, knockout segment is disengaged from integral contact with the interior surface of said formed cage product whereby the formed product can be readily removed from the mold.

7. The animal cage product claimed in claim 6 wherein said first predetermined angle is about one degree off vertical and said second predetermined angle is about two degrees off vertical.

8. The animal cage product claimed in claim 6 wherein said first predetermined distance is approximately 1 and {fraction (1/16)} inches.

9. The animal cage product claimed in claim 1 wherein said first predetermined angle is about one degree off vertical and said second predetermined angle is about two degrees off vertical.

10. The animal cage product claimed in claim 1 wherein said first predetermined distance is approximately 1 and {fraction (1/16)} inches.