Expansible fastener

Claim 2

A plastic fastener for insertion in an opening to be locked therein, the fastener including a head for location at one end of the opening, expansible locking means for location at the other end of the opening, and flexible spaced apart connectors extending between and connected to the head and the expansible means for extension through the opening, the expansible locking means including a pair of toggle members with centrally located, pivotally associated ends movable axially into a collapsed position between the connectors and movable across-center away from the head to an expanded stable overcenter locking position, the toggle members having, at their centrally located ends, an area of substantially reduced thickness forming a pivotal interconnection between the toggle members for pivotal movement of the toggle members between the collapsed and expanded positions and a recess between the centrally located ends when the toggle members are expanded, the connectors being joined to the toggle members at locations on the toggle members spaced sufficiently radially outwardly with the toggle members in the expanded overcenter position to force the flexible members radially outward relatively far from their radial location with the toggle member in their contracted position, whereby upon insertion of the fastener in an opening and expansion of the expansible means the connectors flex about the said other end of the opening well beyond the opening edges, engaging the opening edges, and holding the fastener in place while urging the toggle members against across-center return and collapse.

Claim 3

The fastener according to claim 1, wherein the spaced apart connectors include intermediate portions forming means for engaging edges of an opening to tightly resiliently stretch the interconnecting means between the connection thereof with the expanded toggle Members and points of contact with the opening edges.

Claim 4

The fastener according to claim 1, wherein the toggle members are substantially rigid and the spaced apart connectors are more flexible for extension outwardly about opening edges.

Claim 5

The fastener according to claim 1, wherein the head is a substantially nondeformable member which retains its configuration when the toggle members are expanded and the connectors are resiliently deformed outwardly.

Claim 6

The fastener according to claim 1, including means for preventing further pivotal movement of the toggle members away from their oncenter position when the extensible portions are in said expanded stable position.

Claim 7

The fastener according to claim 5, wherein the further pivotal movement preventing means includes outermost portions of the toggle members extensible outwardly from the connector means upon expansion of the toggle members for engagement with a surface near an opening end.

Claim 8

The fastener according to claim 5, wherein the further pivotal movement preventing means includes centrally located sections of the toggle members placed in stressed condition by further pivotal movement of the toggle members away from their oncenter position.

Claim 9

The fastener according to claim 1, including an opening through said head in alignment with the central pivotal connection to allow forcing of the pivotal connection away from the head to expand the toggle members.

Claim 10

The fastener according to claim 1 for attaching a part to an apertured member, wherein the resilient connectors and toggle members are integrally formed with said part, and said part forms the head of the fastener.

Claim 11

The fastener according to claim 1, wherein the toggle members normally automatically assume the expanded, stable, overcenter condition and are manually collapsible for insertion through an opening, and the connectors comprise means for applying said inwardly directed forces to the expanded toggle members to resist collapse from the normal expanded condition.

Claim 12

The fastener according to claim 10, wherein the head comprises means for extension into an opening to allow return of the toggle members to their normal expanded condition adjacent the further end of the opening, and further including means for withdrawing the head to draw the expanded toggle members toward the further end of the opening.

Claim 13

The fastener according to claim 1, wherein the centrally located ends define means engageable by an inserted member for forcing the arms into the overcenter position.

Claim 14

The fastener according to claim 1 for use with an opening in a relatively thin member, the head defining an opening therethrough, and said toggle members extending longitudinally through said head opening when the locking means is collapsed.

Claim 15

The fastener according to claim 1, for use with an inserted threaded member, wherein the fastener is made of material capable of self-threading engagement by the threaded member to anchor the threaded member.

Claim 16

The fastener according to claim 1, wherein the toggle members are joined with an associated connector at a junction, the junction, toggle members, and connectors are all collapsible to within a predetermined transverse dimension, and the junctions are located on the toggle members for movement outwardly sufficiently beyond said transverse dimension to define means for engaging edges of a hole of said dimension and to define means for applying inward forces between edges of a hole of such dimension and the toggle members to prevent removal of the fastener and return across-center collapse of the toggle members by the application of forces through the connectors to the toggle members.

Claim 17

The fastener according to claim 15 wherein, in the expanded condition, the fastener is free of any direct axial connection through the connectors from said head to the toggle members capable of applying axial forces therealong tending to collapse the toggle members by return, across-center movement.

Claim 18

ThE fastener according to claim 1, wherein the flexible interconnection of the toggle members joins the toggle members together near the surfaces thereof farthest from the fastener head when the toggle members are in their expanded condition, the flexible interconnection and adjacent toggle member ends forming said recess aligned with the head on the same side of the flexible interconnection as the head.

Claim 19

A plastic fastener for insertion in an opening and including a head, expansible toggle members, and connectors, each connector extending from the head to a toggle member, the connectors being flexible, spaced apart, and free of restraining interconnection in the sections of the connectors intermediate the head and the toggle members, the connectors having outer surfaces engageable with an edge of the opening and extensible radially outwardly away from the opening, the toggle members being less easily flexed than the flexible connectors and having distinct central ends, in the expanded condition the toggle member ends having a recess therebetween at a central location, the central toggle member ends being in freely pivotal relation permitting substantially free pivoting of the toggle members about said central location from a collapsed, side-by-side condition, through an aligned condition, to an overcenter, expanded condition in which the toggle members are substantially undeformed, the toggle members in said expanded condition driving the connectors radially outwardly a substantial distance beyond the radial spacing thereof with the toggle members in the collapsed condition to drive the connectors into engagement with opening edges and substantially beyond the opening edges, the connectors when placed in tension between opening edges and their connection with the toggle members, defining means for applying forces to the toggle members toward the opening edges resisting return across-center collapse of the toggle members to make said overcenter condition of the toggle members a stable, self-sustained condition absent any additional member between the head and the toggle members.

Claim 20

A plastic fastener for insertion in an opening and including a head, expansible toggle members, and connectors, each connector extending from the head to a toggle member, the connectors being flexible, spaced apart, and free of restraining interconnection in the sections of the connectors intermediate the head and the toggle members, the connectors having outer surfaces engageable with an edge of the opening and extensible radially outwardly away from the opening, the toggle members being less easily flexed than the flexible connectors and having distinct central ends, in the expanded condition the toggle member ends having a recess therebetween at a central location, the central toggle member ends being in freely pivotal relation permitting substantially free pivoting of the toggle members about said central location from a collapsed, side-by-side condition, through an aligned condition, to an overcenter, expanded condition in which the toggle members are substantially undeformed, the toggle members in said expanded condition driving the connectors radially outwardly a substantial distance beyond the radial spacing thereof with the toggle members in the collapsed condition to drive the connectors into engagement with opening edges and substantially beyond the opening edges, the connectors when placed in tension between opening edges and their connection with the toggle members, defining means for applying forces to the toggle members toward the opening edges resisting return across-center collapse of the toggle members to make said overcenter condition of the toggle members a stable, self-sustained condition absent any additional member between the head and the toggle members.

Claim 21

The fastener according to claim 18, wherein said connectors are connected to the toggle members in angular relation thereto at integrally formed points of angular connection.

Claim 22

The fastener according to claim 19, wherein the fastener is of molded one-piece construction.

Claim 23

A self-opening plastic fastener including a head, toggle members, and spaced connectors, the spaced connectors being integrally molded with the toggle members in a natural, expanded, unbiased, overcenter position, and said connectors diverging from a closely spaced relationship at the connection thereof with the head, to a substantially greater radial spacing at the connection thereof with the toggle members, the toggle members being collapsible by across-center movement of the centrally located ends thereof, forcing the toggle members and connectors to a substantially axially extending disposition of reduced radial extent, and the toggle members and connectors being naturally biased to the expanded overcenter position when in said contracted condition to define an automatically expansible snap opening locking means.

Claim 24

A self-opening plastic fastener including a head, toggle members, and spaced connectors, the spaced connectors being integrally molded with the toggle members in a natural, expanded, unbiased, overcenter position, and said connectors diverging from a closely spaced relationship at the connection thereof with the head, to a substantially greater radial spacing at the connection thereof with the toggle members, the toggle members being collapsible by across-center movement of the centrally located ends thereof, forcing the toggle members and connectors to a substantially axially extending disposition of reduced radial extent, and the toggle members and connectors being naturally biased to the expanded overcenter position when in said contracted condition to define an automatically expansible snap opening locking means.

Claim 25

The fastener according to claim 21 wherein, in the expanded overcenter position of the toggle members, said connectors are joined with the toggle members at locations on the toggle members spaced sufficiently radially outwardly to force the flexible members radially outward relatively far from their radial location with the toggle members in their contracted condition, whereby upon insertion of the fastener in an opening and expansion of the expansible means, the connectors flex about the opening end nearest the toggle members, beyond the edges of the opening, engaging the edges of the opening, and holding the fastener in place while urging the toggle members against across-center return and collapse.

Claim 26

The fastener according to claim 21, wherein said head is narrow for insertion into an opening to permit movement of the toggle members across-center to the stable expanded condition and retraction of the head to cause engagement of the spread-apart connectors with hole edges.

Claim 27

The fastener according to claim 21, for supporting a part in an apertured member, wherein said head of the fastener comprises the part to be supported.

Claim 28

The fastener according to claim 21, wherein the toggle members are relatively long and, when in collapsed generally longitudinally extending condition, extend into an opening in the head.

Claim 29

The fastener according to claim 21 for employment with an opening formed in a member, wherein the connectors define force applying means for extending into engagement with edges of the opening to transmit said inwardly directed forces to the expanded locking means.

Claim 30

The fastener according to claim 21, wherein the toggle members have a pivotal connection at the centrally located ends thereof, and the pivotal connection is normally disposed out of alignment with the connections of the toggle members and the connectors, and is movable further out of alignment away from the head upon application of said inwardly directed forces by the connectors.

Claim 31

The fastener according to claim 27, wherein the connectors define means for transmitting the laterally inwardly directed forces to the toggle members by engagement of the spaced connectors with edges of an opening.