Mirrors having stretched reflective sheet materials

• US 3,880,500 A
• Filed: 12/28/1973
• Issued: 04/29/1975
• Est. Priority Date: 12/28/1973
• Status: Expired due to Term

• Current Assignee: Velcro Industries BV (Chartwell Industries Ltd)
• Original Assignee: Charles Kojabashian
• Inventors: Kojabashian, Charles
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): Tokar, Michael J.
• Application Number:
  US05/429,279
• Time in Patent Office: 487 Days
• Field of Search: 350/288,299,310,295 156/60
• US Class Current: 359/847
• CPC Class Codes: G02B 5/08 Mirrors vehicle mirrors involving special optical features B60R1/08
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

A planar mirror having at least one reflective surface formed by a metallized thin film reflective sheet material in a stretched condition having a frame defined by peripheral members connected in end-to-end relation, each member having a neutral axis of substantially zero deflections due to bending forces applied thereto. First and second similar thin film reflective sheet materials are secured over each side of the frame and maintained in substantially identically stretched conditions such that the bending and compressive forces on the frame members due to the tension in each film are balanced and in equilibrium with the forces caused by the tension in the other film thereby resulting in continuous and optically correct reflecting mirror surfaces on each side of the frame. A method of producing such optically correct mirrors is also disclosed.

Claims

1. A planar mirror having at least one reflective surface formed by a metallized thin film reflective sheet material in a stretched condition over a supporting frame comprising:

a frame defined by peripheral members connected in end-to-end relation, each member having a neutral axis of substantially zero deflection due to bending forces applied to said member;

a first metallized thin film reflective sheet material in a stretched condition over a first side of said frame;

a second thin film sheet material in a stretched condition over the opposite side of said frame;

means for securing each of said sheet materials to peripheral portions of said frame while maintaining them in a stretched condition over said frame, said sheet materials Being substantially similar and maintained in substantially identical stretched conditions such that the bending and compressive forces on the frame members due to each stretched sheet material are in balanced equilibrium with the bending and compressive forces due to the other stretched sheet material and a continuous and optically correct reflecting mirror surface is thereby created on at least one side of the frame.

2. The mirror according to claim 1 wherein each thin film sheet material is a reflective sheet material, and thereby creates a continuous and optically correct reflective mirror on each side of said frame.

3. The mirror according to claim 2 wherein said thin film sheet material are metallized polyester reflective sheet materials and said mirror has opposite dual reflective surfaces.

4. The mirror according to claim 3 wherein said polyester thin film sheet materials are comprised of polyethylene terephthalate.

5. The mirror according to claim 4 wherein each of said frame members has a substantially rectangular cross-sectional configuration, a first forward peripheral surface portion on the first side of said frame and a second peripheral surface portion on the opposite side of the frame, and each member has a neutral axis of substantially zero deflection due to compressive and bending forces on the frame, said axis passing through a centroid of each frame member and extending along the length of said member, said materials being secured to the respective peripheral surface portions on each side of the frame.

6. The mirror according to claim 5 wherein each reflective sheet material is adhesively secured to the respective forward and rearward surface portions of the side frame members.

7. The mirror according to claim 4 wherein each frame member has an outer side surface portion and the side surface portions of each member define a peripheral side surface portion of the frame, and each sheet of thin film material is secured to a part of the side surface portion of each member and bent over a corner portion thereof while said materials are maintained in a stretched condition over each side of the frame.

8. The mirror according to claim 7 wherein each reflective sheet material is adhesively secured to the respective part of the peripheral side surface portions of the frame.

9. The mirror according to claim 1 wherein each peripheral frame member comprises a channel-like member having a cross-section defined by a peripheral side member extending laterally from a first surface of the frame to the second surface thereof, upper and lower flange members extending from said side member toward the central portion of the frame, a raised peripheral ridge on the outer side of each flange, and said stretched reflective materials are positioned over opposed side portions of the frame and maintained in said stretched condition over the peripheral ridge of each frame member and secured to the outer side surface of the peripheral side member of each channel-like frame member, said stretched reflective sheet materials being maintained in substantially similar stretched conditions such that the bending forces of each material are in balanced equilibrium thereby creating a continuous and optically correct reflecting mirror surface on at least one side of the frame.

10. The mirror according to claim 9 wherein each thin film sheet material is a reflective sheet material, and a continuous and optically correct reflecting mirror surface is thereby provided on both sides of said frame.

11. The mirror according to claim 10 wherein a supporting substrate member is positioned within the frame and gripped between the upper and lower flange members of each frame member so as to provide support for said frame thereby resulting in improved balanced equilibrium between the bending and compressive forces caused by the stretched condition of each thin film sheet material.

12. In a planar mirror having at least one reflective surface formed by a metallized polyester Reflective sheet material supported over a peripheral frame, the combination which comprises:

a plurality of elongated members connected in end-to-end relationship to define said frame, each member having a forward surface portion and a rearward surface portion defining the periphery of said frame, each frame member having a neutral axis of substantially zero deflections due to compressive and bending forces applied to said member, a first sheet of metallized thin film reflective polyester supported over one side of said frame and secured along the periphery thereof, a second sheet of metallized thin film reflective polyester supported over the second side of said frame and secured along the periphery thereof, said sheet materials being substantially identical materials and being maintained in substantially equal stretched conditions over each side of said frame such that bending and compressive forces on the frame members due to each stretched film material are substantially cancelled thereby minimizing frame distortion and resulting in a dimensionally stable frame and a uniform and optically correct mirror surface on each side of the frame.