Method of making a baffled waterbed

• US 4,141,770 A
• Filed: 05/16/1977
• Issued: 02/27/1979
• Est. Priority Date: 05/16/1977
• Status: Expired due to Term

• Current Assignee: Carlos A. Mollura
• Original Assignee: Carlos A. Mollura
• Inventors: Mollura, Carlos A.
• Primary Examiner(s): Stein, Mervin
• Assistant Examiner(s): Grosz, Alex
• Application Number:
  US05/796,853
• Time in Patent Office: 652 Days
• Field of Search: 5/365, 5/367, 5/368, 5/369, 5/370, 5/371, 5/341, 5/349, 5/350, 156/218, 156/212, 156/226, 156/297, 156/227, 297/DIG. 8
• US Class Current: 156/218
• CPC Class Codes: A47C 27/085 of liquid type, e.g. filled with water or gel
• CPC Class Codes: A47C 27/087 with means for connecting opposite sides, e.g. internal ties or strips
• CPC Class Codes: B29C 65/04 Dielectric heating, e.g. high-frequency welding , i.e. radio frequency welding of plastic materials having dielectric properties, e.g. PVC
• CPC Class Codes: B29C 65/58 Snap connection
• 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 66/43 Joining a relatively small portion of the surface of said articles B29C66/45 takes precedence
• CPC Class Codes: B29C 66/4324 for making closed loops, e.g. belts
• CPC Class Codes: B29C 66/474 said single elements being substantially non-flat
• CPC Class Codes: B29C 66/53462 joining substantially flat covers and substantially flat bottoms to open ends of container bodies
• CPC Class Codes: B29C 66/54 Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
• CPC Class Codes: B29C 66/543 joining more than two hollow-preforms to form said hollow articles
• CPC Class Codes: B29C 66/61 Joining from or joining on the inside for making tubes by bending sheets and joining from the inside B29C53/387
• CPC Class Codes: B29C 66/63 Internally supporting the article during joining B29C66/49 takes precedence
• CPC Class Codes: B29C 66/81427 comprising a single ridge, e.g. for making a weakening line; comprising a single tooth
• CPC Class Codes: B29C 66/843 Machines for making separate joints at the same time in different planes; Machines for making separate joints at the same time mounted in parallel or in series
• CPC Class Codes: B29L 2022/02 Inflatable articles balls B29L2031/54 ; inner tyres B29L2023/245
• CPC Class Codes: B29L 2031/751 Mattresses, cushions upholstery B29L2031/58
• CPC Class Codes: Y10S 5/932 Seals and sealing methods, for plastics
• CPC Class Codes: Y10T 156/1038 Hollow cylinder article
• CPC Class Codes: Y10T 156/1051 by folding
• CPC Class Codes: Y10T 156/1089 : of discrete laminae to single face of additional lamina

Abstract

To achieve maximum strength and reliability, a bag for use as a waterbed mattress is formed entirely of lap welds, that is, without any butt welds. My U.S. Pat. No. 3,825,172 discloses a lap weld method in which a length of plastic material is rolled to form a tube, the ends being lapped and partially welded to leave an access opening to the inside of the bag. The tube is telescoped over a welding die having the cross sectional configuration of the mattress, but axially short. The tube is accordion folded about the thin form with the ends of the tube turned inwardly over the peripheral rims of the form. End pieces are then welded in place. The form is removed through the access opening and the partial weld completed by the aid of a separator stick removable through the fill hole. To baffle the bag without changing the foregoing process, baffles are formed as a pair of detachably connectable elements respectively welded to the opposite sides of the tube that later will form the top and bottom layers of the mattress. The elements being detached from each other, fold with the tube along sides of the welding die. As a final assembly step, the baffle elements are connected together by simple manipulations through a later closed gap in the lap weld of the tube or by manipulations from the outside of the completed bag. The connected baffles operate to damp wave motion of fluid in the bag.

Claims

1. The process of making a lap welded substantially closed baffled bag which includes:

(a) attaching at longitudinally spaced portions of a sheet of material, corresponding parts of two part baffle structures;

(b) forming a tube by looping the sheet of material so that companion baffle parts are inside;

(c) lap welding the ends of the sheet, but leaving a gap intermediate the ends of the weld so formed;

(d) telescoping the tube over a die having rims at opposite ends spaced from each other substantially less than the designed length of the tube;

(e) placing the end edges of the tube respectively adjacent the rims while gathering the central portion of the tube so that the respective baffle parts fall along opposite sides of the die;

(f) inwardly folding the edges of the tube over the rims;

(g) placing end members over the inwardly folded edges of the tube;

(h) adhering the end members to the folded edges;

(i) removing the die from the tube through the gap;

(j) attaching the distal ends of the companion baffle parts together by the aid of detachable fasteners formed thereon; and

(k) completing the lap weld of the tube by closing said gap.

2. The process as set forth in claim 1 in which said gap is closed as a last step of said process, said detachable fasteners being accessible for manipulation through said gap.

3. The process as set forth in claim 1 in which said baffle parts are attached together as the last step, said fasteners being manipulable through said sheet of material.