Method of forming orthopaedic gel pads

• US 4,913,755 A
• Filed: 03/16/1988
• Issued: 04/03/1990
• Est. Priority Date: 03/16/1988
• Status: Expired due to Term

• Current Assignee: Ossur hf
• Original Assignee: Royce Medical Company (Ossur hf)
• Inventors: Grim, Tracy E.
• Primary Examiner(s): Dawson, Robert A.
• Assistant Examiner(s): Yoder, Michele K.
• Application Number:
  US07/168,681
• Time in Patent Office: 748 Days
• Field of Search: 128/80 H, 128/89 R, 128/166, 156/285, 156/145, 156/299, 156/300, 156/245, 425/388, 264/516, 264/510
• US Class Current: 156/145
• CPC Class Codes: A61F 2007/0042 Knee
• CPC Class Codes: A61F 2007/0043 Lower leg, calf
• CPC Class Codes: A61F 2007/0044 Ankle
• CPC Class Codes: A61F 2007/0045 Foot
• CPC Class Codes: A61F 2007/0098 ways of manufacturing heating or cooling devices for therapy
• CPC Class Codes: A61F 5/0111 for the feet or ankles
• CPC Class Codes: A61F 7/02 Compresses or poultices for effecting heating or cooling
• CPC Class Codes: Y10T 156/1093 with covering of discrete laminae with additional lamina

Abstract

A method for forming gel-filled cushion pads that provide a resilient support against the ankle, comprises the use of a vacuum chamber substantially covered at the top with a perforated base plate. A thin, rubber foam layer spacer pad with openings is overlaid on the base plate. A thin, rubber foam layer front pad with openings is overlaid on the spacer pad in alignment with the spacer pad openings. Adhesive material is coated on the top surface of the front pad. A thin layer of urethane is overlaid on the adhesive coated upper surface of the front pad and vacuum is applied to pull the urethane layer toward the base plate. With the urethane layer substantially conformed to the inner walls of these pads, a patterned pocket is formed for receiving liquid gel. Then, a predetermined amount of liquid gel is poured into this pocket and allowed to cool and solidify to form a dense semi-solid gel. A rubber foam back pad covered with adhesive material on its bottom surface is then overlaid onto the urethane layer to enclose the gel material between the urethane film, and the back pad. The assembly comprising the back pad, gel layers, front pad, and urethane layer is removed from the base plate. Because each front pad may include several patterned opening on its surface, several contiguous units of gel-filled cushion pads may be formed in this process and cut accordingly.

Claims

1. A method for forming orthopaedic gel pad assemblies using a substantially flat perforated base plate with a vacuum chamber comprising the steps of:

placing a spacer pad over the base plate with at least one patterned opening through the spacer pad conforming to the desired shape of the gel pad, with drilled holes in the base plate communicating between said patterned opening and the vacuum chamber

placing an apertured front pad over the spacer pad with a patterned opening through the front pad aligned with the patterned opening of the spacer pad;

applying an adhesive coating to the upper surface of the front pad;

placing a thin flexible plastic film or sheet over the adhesive coated surface of the front pad;

drawing air through holes in the substantially flat base plate for exerting force on the plastic film and pulling the film down into the opening and in engagement with said substantially flat plate;

pouring a measured quantity of liquid gel into said patterned opening;

letting the gel harden to a semi-solid state;

placing a backing layer on top of the plastic sheet, with the plastic sheet being adhered to the backing layer, to confine the gel into the resultant pocket with no gel exposed, to protect the gel from contamination;

separating the front pad, the confined gel and the backing layer from the spacer pad and the base plate; and

cutting the layers around the confined gel to form an orthopaedic gel assembly with the gel pad protruding from the front pad thereof by a distance equal to the thickness of the spacer pad.

2. A method for forming orthopaedic gel cushion pads as defined in claim 1 wherein open cell foam material is located in the liquid gel to prevent gel migration.

3. A method as defined in claim 1 wherein the spacer pad includes a layer of foam rubber.

4. A method as defined in claim 1 wherein the openings in the aperture front pad correspond substantially with the openings on the spacer pad.

6. A method as defined in claim 1 wherein said base plate includes a multitude of drilled holes on its surface spaced along the inside of said openings to insure conformance of the film to the shape of the opening.

7. A method as defined in claim 1 wherein said spacer pad and backing pad include a layer of foam rubber.

8. A method as defined in claim 1 wherein said spacer pad, front pad and back pad have substantially equal thickness.

9. A method as defined in claim 1 wherein the patterned opening on the surface of said spacer pad is substantially identical in configuration to the patterned opening on the surface of said front pad.

13. A method as defined in claim 1 wherein a plurality of said gel pad assemblies are formed concurrently.

14. A method as defined in claim 1 wherein said front pad and said backing layer are formed of foam rubber in sheet form.

5. A method as defined in claim wherein the apertured front pad includes a layer of foam rubber.

10. A general purpose method for forming substantially flat orthopaedic gel pads of any desired peripheral configuration and thickness using a flat perforated base plate with a vacuum chamber comprising the steps of:

placing a spacer pad over the base plate, with a patterned opening through the spacer pad and having the desired configuration of the gel pads, and with a plurality of drilled holes in the base plate communicating with the patterned opening;

placing a thin flexible plastic film or sheet over and extending down into the opening in the spacer pad;

drawing air through holes in the base plate for exerting force on the plastic film and pulling the film down into the opening and in engagement with said plate;

pouring a measured quantity of liquid gel into said patterned opening;

letting the gel harden to a semi-solid state;

placing a backing layer on top of the plastic sheet;

securing the backing layer to said plastic sheet to confine the gel into the resultant pocket and to seal the gel against contamination;

removing the plastic sheet, the gel and the backing layer from the spacer pad; and

cutting the layers around the confined gel to form an orthopaedic gel pad;

whereby any desired gel pad peripheral configuration may be formed using the same perforated base plate and vacuum chamber, using spacers having differently shaped openings.

15. A method as defined in claim 10 wherein said backing layer is formed of foam rubber in sheet form.

11. A method for forming orthopaedic gel pad assemblies using a substantially flat perforated base plate with a vacuum chamber comprising the steps of:

placing a spacer pad over the base plate with a plurality of patterned openings through the spacer pad conforming to the desired shape of the gel pad, with drilled holes in the base plate communicating between said patterned opening and the vacuum chamber;

placing an apertured front pad over the spacer pad with patterned openings through the front pad aligned with the patterned openings of the spacer pad;

applying an adhesive coating to the upper surface of the front pad;

placing a thin flexible plastic film or sheet over the adhesive coated surface of the front pad;

drawing air through holes in the substantially flat base plate for exerting force on the plastic film and pulling the film down into the opening and in engagement with said substantially flat plate;

pouring a measured quantity of liquid gel into said patterned openings;

letting the gel harden to a semi-solid state;

placing a backing layer on top of the plastic sheet, with the plastic sheet, being adhered to the backing layer, to confine the gel into the resultant pockets with no gel exposed, to protect the gel from contamination;

separating the front pad, the confined gel and the backing layer from the spacer pad and the base plate; and

cutting the layers around the confined gel to form an orthopaedic gel pad assemblies, with the gel pad protruding from the front thereof by a distance equal to the thickness of the spacer pad.

16. A method as defined in claim 11 wherein said front pad and said backing layer are formed of foam rubber in sheet form.

12. A general purpose method for forming substantially flat orthopaedic gel pad assemblies, of any desired peripheral configuration and thickness, using a flat perforated base plate with a vacuum chamber, comprising the steps of:

placing a spacer pad over the base plate, with a plurality of patterned openings through the spacer pad having the desired peripheral configuration of the gel pads, and with a plurality of drilled holes in the base plate communicating between said patterned openings and the vacuum chamber;

placing a thin flexible plastic film or sheet over and extending down into the openings in the spacer pad;

drawing air through holes in the base plate for exerting force on the plastic film and pulling the film down into the openings and in engagement with said plate;

pouring a measured quantity of liquid gel into said patterned openings;

letting the gel harden to a semi-solid state;

placing a backing layer on top of the plastic sheet;

securing the backing layer to said plastic sheet to confine the gel into the resultant pockets and to seal the gel against contamination;

removing the thin film, the gel and the backing layer from the spacer pad; and

cutting the layers around the confined gel to form a plurality of orthopaedic gel pad assemblies;

whereby any desired gel pad peripheral configuration and thickness may be formed using the same substantially perforated base plate and vacuum chamber, using spacer pads having shaped openings of the desired configuration, and spacer pads of the desired thickness.

17. A method as defined in claim 12 wherein said backing layer is formed of foam rubber in sheet form.