Fastener installation method

• US 4,093,491 A
• Filed: 03/18/1974
• Issued: 06/06/1978
• Est. Priority Date: 06/24/1971
• Status: Expired due to Term

• Current Assignee: William H. Trembley
• Original Assignee: Hugh G. Whelpton, William H. Trembley
• Inventors: Trembley, William H., Whelpton, Hugh G.
• Primary Examiner(s): Powell, William A.
• Assistant Examiner(s): Bokan, Thomas
• Application Number:
  US05/452,097
• Time in Patent Office: 1,541 Days
• Field of Search: 52/617, 52/309.2, 117/122 H, 151/41.7, 156/293, 156/298, 156/303.1, 156/309, 156/331, 161/214, 161/327, 427/207 A, 428/116, 428/435, 428/458, 428/474
• US Class Current: 156/66
• CPC Class Codes: B29C 65/00 Joining or sealing of preformed parts , e.g. welding of plastics materials; Apparatus therefor general aspects of processes or apparatus for joining preformed parts B29C66/00; using porous material formed by internal pressure generated therein for joining preformed parts B29C44/1228, B29C44/326
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/42 between pre-assembled parts B29C65/605 takes precedence
• CPC Class Codes: B29C 65/425 characterised by the composition of the molten plastics applied between pre-assembled parts
• CPC Class Codes: B29C 65/44 Joining a heated non plastics element to a plastics element
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/486 characterised by their physical form being non-liquid, e.g. in the form of granules or powders B29C65/50 takes precedence
• CPC Class Codes: B29C 65/5057 positioned between the surfaces to be joined B29C65/5035 takes precedence
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/131 Single flanged joints, i.e. one of the parts to be joined being rigid and flanged in the joint area
• CPC Class Codes: B29C 66/474 said single elements being substantially non-flat
• CPC Class Codes: B29C 66/72525 comprising honeycomb cores
• CPC Class Codes: B29C 66/8161 said pressing elements being supported or backed-up by springs or by resilient material
• CPC Class Codes: B29C 66/818 characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps characterised by the heating means B29C65/24; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps
• CPC Class Codes: B29C 66/8221 Scissor or lever mechanisms, i.e. involving a pivot point
• CPC Class Codes: B29C 66/8322 Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/861 Hand-held tools
• CPC Class Codes: B29C 66/8614 Tongs, pincers or scissors
• CPC Class Codes: B29C 66/91212 involving measurement means being part of the welding jaws, e.g. integrated in the welding jaws
• CPC Class Codes: B29C 66/91231 : of the joining tool
• CPC Class Codes: B29C 66/91421 : of the joining tools
• CPC Class Codes: B29C 66/91431 : the temperature being kept constant over time
• CPC Class Codes: B29C 66/91641 : the heat or the thermal flux being non-constant over time
• CPC Class Codes: B29C 66/961 : involving a feedback loop mechanism, e.g. comparison with a desired value
• CPC Class Codes: Y10T 428/24149 : Honeycomb-like

Abstract

An installation tool and method of using same for securing fastener insert elements to substrates where the fastener element is provided with a heat meltable material which serves to bond the fastener to the substrate, the installation tool comprising a controllably heated tip for contact with the fastener and a timer means for indicating when a required heating cycle has expired and the tool should be withdrawn from the fastener: the method provides the heating of the meltable material, a resin, above the meltable temperature, but not above an upper temperature beyond which a decrease in resultant bond strength would occur.

Claims

1. A method of installing a fastener insert to a panel having a cavity extending thereinto from one face thereof, the method comprising the following steps in combination:

providing a fastener insert having an axially extending body and a flanged heat conductive head portion integrally formed at one end of the body;

providing on an undersurface of said flange synthetic resin bonding material which is solid at room temperature, melts at an elevated temperature and resolidifies on cooling to bond adjacent structures;

providing a heating tool having an operating temperature substantially above the melting temperature of said bonding material;

providing a panel having a cavity, said cavity having a cross-sectional size adapted to receive said body and a depth sufficient to allow engagement between said bonding material and portion of the outer surface of said panel adjacent said cavity when said body is inserted in said cavity;

inserting said body in said cavity to provide engagement between said flanged head portion and said bonding material and between said bonding material and said outer surface portions of said panel;

transferring heat from said heating tool to said fastener insert and to said bonding material by placing said heating tool in proximity to said insert, and thereby melting said bonding material;

said bonding material being characterized by yielding increased bonding strength between said insert and panel after cooling upon an increase in the time of heat transfer from said heating tool beyond the time required to melt said bonding material, and up to a maximum time, beyond which said maximum time the bonding strength of said bonding material deteriorates, and

stopping the heating of said bonding material after melting thereof at a time to effect a resulting bonding strength which is approximately the maximum bonding strength of said bonding material.

2. The method of claim 1, wherein said last mentioned step comprises stopping the heating at a time prior to the time at which the resulting bonding strength deteriorates.

3. The method of claim 1, wherein said heating is effected by engaging a portion of said heating tool with the surface of said flanged head portion remote from said panel.

4. The method of claim 3, further comprising:

applying pressure on said flanged head portion during the heating of said head portion to thereby force said head portion toward said panel and against said bonding material.

5. The method of claim 1, wherein the heating tool operating temperature is approximately 600°

- 900°

F.

6. The method of claim 1, said body being tubular, and wherein said bonding material is additionally heated by introducing a heated element into said body.

7. The method of claim 1, wherein said bonding material consists essentially of a polyamide.

8. The method of claim 7, said bonding material consisting essentially of nylon.