Apparatus for bonding a cover material to foam

• US 6,003,579 A
• Filed: 01/28/1997
• Issued: 12/21/1999
• Est. Priority Date: 03/25/1996
• Status: Expired due to Fees

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Parrish, Kenneth R.
• Primary Examiner(s): Aftergut, Jeff H.
• Assistant Examiner(s): HENDRIX, ROBERT T
• Application Number:
  US08/788,432
• Time in Patent Office: 1,057 Days
• Field of Search: 156/285, 156/212, 156/214, 156/308.2, 156/309.6, 156/245, 156/497, 156/498, 156/475, 156/580
• US Class Current: 156/498
• CPC Class Codes: B29C 63/025 applied by a die matching with the profile of the surface of resilient articles, e.g. cushions, seat pads
• CPC Class Codes: B29C 65/10 using hot gases (e.g. combustion gases) or flames coming in contact with at least one of the parts to be joined
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/5057 positioned between the surfaces to be joined B29C65/5035 takes precedence
• CPC Class Codes: B29C 65/7841 Holding or clamping means for handling purposes clamping means for the purpose of applying pressure on the parts to be joined, in the area to be joined B29C66/81; work holders in general B25B; devices for holding or positioning work for welding metal B23K37/04
• CPC Class Codes: B29C 65/7847 using vacuum to hold at least one of the parts to be joined vacuum work holders in general B25B11/005
• CPC Class Codes: B29C 66/0342 Cooling, e.g. transporting through welding and cooling zone
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/301 Three-dimensional joints, i.e. the joined area being substantially non-flat B29C66/5223, B29C66/5224, B29C66/5225 take precedence
• CPC Class Codes: B29C 66/3494 while keeping the welding zone under pressure
• CPC Class Codes: B29C 66/5326 said single elements being substantially flat
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/723 being multi-layered B29C66/7292, B29C66/72941 take precedence
• CPC Class Codes: B29C 66/72341 for gases
• CPC Class Codes: B29C 66/727 being porous, e.g. foam
• CPC Class Codes: B29C 66/729 Textile or other fibrous material made from plastics
• CPC Class Codes: B29C 66/80 General aspects of machine operations or constructions and parts thereof
• CPC Class Codes: B29C 66/81241 being porous or sintered
• CPC Class Codes: B29C 66/81423 being concave
• CPC Class Codes: B29C 66/8167 Quick change joining tools or surfaces
• CPC Class Codes: B29C 66/8242 : Pneumatic or hydraulic drives using fluid pressure directly acting on the parts to be joined B29C66/8266
• CPC Class Codes: B29C 66/8322 : Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/9141 : by controlling or regulating the temperature
• CPC Class Codes: B29C 66/91413 : the parts to be joined having different temperatures
• CPC Class Codes: B29C 66/919 : characterised by specific temperature, heat or thermal flux values or ranges specific electrical resistance values B29C66/81262
• CPC Class Codes: B29C 66/91931 : in explicit relation to the fusion temperature or melting point of the material of one of the parts to be joined
• CPC Class Codes: B29C 66/92653 : said stops being adjustable
• CPC Class Codes: B29C 66/92655 : by using several stops
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/0097 : Glues or adhesives, e.g. hot melts or thermofusible adhesives
• CPC Class Codes: B29K 2105/04 : cellular or porous
• CPC Class Codes: B29L 2031/751 : Mattresses, cushions upholstery B29L2031/58
• CPC Class Codes: B29L 2031/771 : Seats
• CPC Class Codes: Y10T 156/1028 : by bending, drawing or stretch forming sheet to assume shape of configured lamina while in contact therewith
• CPC Class Codes: Y10T 156/1031 : with preshaping of lamina

Abstract

A method and apparatus for bonding a cover (22) over an undulating surface of a foam cushion (10) by placing the cover, an adhesive layer (82) and the cushion on a tool (18), compressing the cushion with a compression plate (58) to force ambient temperature air from an interior thereof, piercing the cushion with a plurality of needles (44) extending through holes (60) in the compression plate, releasing the compression, heating compressed air and ejecting the heated air from the needles into the interior of the cushion to elevate the temperature of the cushion. The heat is transferred from the cushion (10) to melt the adhesive (82). The cushion (10) is again compressed by the compression plate (58) to force the heated air from the interior of the cushion and the compression is released to allow ambient temperature air to flow into the interior of the cushion to cure the adhesive (82) and bond the cover (22) to the cushion (10). The needles (44) are extracted from the cushion as the compression plate is held against the backside of the cushion to hold the cushion and the cover against the tool (18).

Claims

1. A method of bonding a cover layer of material over a surface of a foam cushion comprising the steps of:

a. spreading a finished side of a cover over a working surface of a tool;

b. placing an adhesive on a backside of the cover;

c. placing a foam cushion on the working surface of the tool;

d. compressing the cushion to force air from an interior of the cushion;

e. removing the compression from the cushion; and

f. injecting heated air into the interior of the cushion to elevate a temperature of the cushion thereby melting the adhesive with the transfer of heat from the heated cushion to thereby bond the cover to the cushion.

2. The method according to claim 1 wherein said step e. includes piercing the cushion with a plurality of needles and ejecting the heated air from the needles and into the surrounding cushion to elevate the temperature of the cushion.

3. The method according to claim 2 wherein said step d. includes disposing a compression plate with holes extending therethrough on a backside of the cushion and holding the compression plate against the backside of the cushion to compress the cushion against the cover and the tool and said step e. includes extending the needles through the holes in the compression plate.

4. The method according to claim 1 including a further step g. of compressing the cushion to force the heated air from the interior of the cushion thereby cooling the cushion to cure the adhesive to thereby bond the cover to the cushion.

5. The method according to claim 4 wherein said step g. includes applying a vacuum pressure to the needles to draw the heated air from the interior of the cushion thereby cooling the cushion to cure the adhesive to thereby bond the cover to the cushion.

6. The method according to claim 2 wherein said step f. includes maintaining a substantially equal mass flow rate of the heated air through each of the needles.

7. The method according to claim 1 including applying a vacuum pressure over the working surface of the tool to draw the cover against the working surface of the tool prior to performing said step c.

8. A method of bonding a cover layer of material over the surface of a foam cushion comprising the steps of:

a. moving a tool from a working position beneath a plurality of needles to a loading position with a working surface of the tool facing generally forwardly;

b. spreading a finished side of a cover over the working surface of the tool;

c. placing an adhesive on a backside of the cover;

d. applying a vacuum pressure over the working surface of the tool to draw the cover against the working surface of the tool;

e. moving the tool from the loading position to the working position;

f. placing a foam cushion on the working surface of the tool with a surface to be bonded to the cover on the adhesive;

g. disposing a compression plate with holes extending therethrough on a backside of the cushion to compress the cushion and force air from an interior of the cushion;

h. piercing the cushion with a plurality of needles extending through the holes in the compression plate to varying depths in the cushion;

i. lifting the compression plate to remove the compression from the cushion;

j. injecting heated air into the interior of the cushion through the needles to elevate a temperature of the cushion thereby melting the adhesive with the transfer of heat from the heated cushion;

k. lowering the compression plate to compress the cushion and force the heated air from the interior of the cushion thereby cooling the cushion to cure the adhesive to thereby bond the cover to the cushion;

l. lifting the compression plate to remove the compression from the cushion to allow ambient temperature air to flow into the interior of the cushion to cure the adhesive; and

m. extracting the needles from the cushion while holding the compression plate against the backside of the cushion to hold the bonded cushion and cover against the tool as the needles are extracted.

9. The method according to claim 8 wherein after said step j. applying a vacuum pressure to the needles to draw the heated air from the interior of the cushion thereby cooling the cushion to cure the adhesive to thereby bond the cover to the cushion.

10. The method according to claim 8 including a step of heating compressed air to a temperature above the temperature of the cushion and supplying the heated compressed air to the needles.

11. An apparatus for bonding a cover of material to a surface of a foam cushion with an adhesive comprising:

a support structure;

a tool supported by said support structure and having a working surface;

a vacuum source connected to said tool for applying vacuum pressure over said working surface of said tool to draw a cover against said working surface;

an array of needles movably supported by said support structure for piercing a foam cushion placed on said working surface;

a compression plate having holes extending therethrough for receiving said needles extending through said holes, said compression plate being movably supported by said support structure for movement relative to said needles; and

a plenum chamber having a wall, said needles extending through said wall and having bores therein for conveying heated air from said plenum to ejection ports in said needles for heating an interior of a cushion pierced by said needles, said vacuum source being connected to said plenum for subsequently drawing the heated air from the interior of the cushion.