Method of and apparatus for setting blind fasteners

Claim 2

Apparatus for setting fasteners having apertures therein, which comprises: a mandrel assembly adapted to be expanded from an unexpanded mode to an expanded mode mounted for movement relative to an anvil surface, said mandrel assembly being adapted to receive a fastener thereon in its unexpanded mode by effecting relative axial movement between the mandrel assembly and the aperture in the fastener, the mandrel assembly in its unexpanded mode occupying substantially the entire cross-sectional area of the aperture in the fastener when the fastener is received thereon, means for expanding the mandrel assembly to its expanded mode wherein a portion thereof has a cross-section greater than the aperture in the fastener, and means for driving the expanded mandrel assembly toward the anvil surface to set the fastener.

Claim 3

Apparatus according to claim 1, wherein: the mandrel assembly includes a shaft having an enlarged front portion.

Claim 4

Apparatus according to claim 2, wherein the enlarged front portion of the shaft includes a tip tapered to a point from a base having a cross-section larger than that of the shaft and a portion of decreasing cross-section between the base of the tapered tip and the shaft proper.

Claim 5

Apparatus according to claim 2, wherein the means for expanding the mandrel assembly includes a sleeve of resilient material mounted for slidable movement on the mandrel to and from a position whereat the leading edge thereof is mounted adjacent the thickest part of the enlarged front portion thereof, said sleeve being segmented adjacent the leading edge thereof.

Claim 6

Apparatus according to claim 4, wherein: the mandrel shaft is circular in cross-section and the enlarged front portion of the mandrel includes a tapered conical tip and a frustoconical portion of decreasing cross-section between the base of the conical tip and the shaft, and the sleeve is tubular and the segments thereof are in cross-section sections of an annular ring.

Claim 7

Apparatus according to claim 4, wherein: the mandrel shaft is circular in cross-section and the enlarged front portion of the mandrel includes a tapered conical tip and a frustoconical portion of decreasing cross-section between the base of conical tip and said shaft, and said sleeve is tubular and at least portions of the segments thereof are triangular in cross-section, one apex of the triangle being pointed radially outwardly to engage and sever the end of the fastener.

Claim 8

Apparatus according to claim 4, wherein: at least a portion of the mandrel shaft is of triangular cross-section and the enlarged front portion of the mandrel includes a tapered conical tip and a substantially frustoconical portion of decreasing cross-section between the conical tip and the triangular cross-section, the substantially frustoconical section including triangular flats faired into the sides of the triangular shaft, and the sleeve segments are secant sections of a circle circumscribed about the triangle of the shaft cross-section.

Claim 9

Apparatus for setting fasteners having apertures, comprising: a housing including an anvil surface with an aperture therein, a mandrel assembly mounted in said housing and extending out of said aperture, said mandrel assembly being adapted to be expanded from an unexpanded mode to an expanded mode and to receive a fastener thereon in its unexpanded mode for setting by effecting relative axial movement between the mandrel assembly and the aperture in the fastener, the mandrel assembly in its unexpanded mode occupying substantially the entire aperture in the fastener when the fastener is received thereon, means for expanding the mandrel assembly on the side of the fastener away from the anvil surface to a cross-section greater than the diameter of the aperture in the fastener, and means mounted in said housing for driving said expanded mandrel assembly relative to said anvil surface to set the fastener, said means including a cylinder and a piston reciprocal in the cylinder and connected to said mandrel assembly.

Claim 10

Apparatus for setting fasteners having apertures, comprising: a housing including an anvil surface with an aperture therein, a mandrel assembly mounted in said housing and extending out of said aperture, said mandrel assembly being adapted to be expanded from an unexpanded mode to an expanded mode and to receive a fastener thereon in its unexpanded mode for setting by effecting relative axial movement between the mandrel assembly and the aperture in the fastener, the mandrel assembly in its unexpanded mode occupying substantially the entire aperture in the fastener when the fastener is received thereon, means for expanding the mandrel assembly on the side of the fastener away from the anvil surface to a cross-section greater than the diameter of the aperture in the fastener, and means mounted in said housing for driving said expanded mandrel assembly relative to said anvil surface to set the fastener, said means including a cylinder and a piston reciprocal in the cylinder and connected to said mandrel assembly.

Claim 11

Apparatus according to claim 8, wherein: said mandrel assembly includes a shaft having an enlarged front portion, and the means for expanding the mandrel assembly includes a sleeve having a segmented front portion, said sleeve being mounted on the mandrel shaft for movement relative thereto to and from a position whereat at least a portion of the segmented front thereof is adjacent the thickest part of the enlarged front portion of the mandrel shaft such that the thickness of the sleeve segments is added thereto.

Claim 12

Apparatus according to claim 9, wherein the means for moving the sleeve relative to the mandrel shaft includes an enlarged portion provided on said sleeve at the rear thereof and a collar mounted on said mandrel and movable within said enlarged sleeve portion upon the rearward movement of the piston.

Claim 13

Apparatus according to claim 8, wherein: a chamber is provided in said housing between said anvil surface and said cylinder, said chamber communicating with said aperture in the anvil surface, said mandrel assembly includes: a shaft portion extending from the piston through said chamber and out said aperture, an enlarged front portion mounted on the end of the shaft portion extending from the aperture, and a collar portion mounted on the shaft portion in said chamber, said means for expanding the mandrel assembly includes a member mounted for slidable movement with respect to said shaft and having a sleeve portion with a segmented front end extending through said aperture to a position normally adjacent the enlarged front portion of the mandrel shaft and a hollow, enlarged portion connected to said sleeve portion and mounted for movement in said chamber, said hollow enlarged portion enclosing said collar on the shaft, rearward movement of the piston being operable to first expand the mandrel assembly as the enlarged shaft portion is moved relative to the sleeve segments and the latter surround at least a portion of the enlarged front end, adding their thickness thereto, and further rearward movement of the piston being operable to drive the expanded mandrel assembly into the fastener as the collar strikes the rear of the hollow enlarged portion of the expanding member and carries it to the rear along therewith.

Claim 14

Apparatus according to claim 9, wherein said driving means further includes a spring mounted between the back of the piston and the back of the cylinder to bias the enlarged front of the mandrel shaft away from said anvil surface and means for admitting fluid to said cylinder in front of said piston to expand the mandrel assembly by causing movement of the sleeve relative to the mandrel shaft and to drive the expanded mandrel assembly toward said anvil surface.

Claim 15

Apparatus according to claim 11, wherein the shaft portion of the mandrel is circular in cross-section and the enlarged front portion of the mandrel shaft includes an enlarged conical tip and a frustoconical portion of decreasing cross-section between the base of the conical tip and the shaft.

Claim 16

Apparatus according to claim 13, wherein: said chamber is cylindrical, said sleeve is tubular, said segments are arcuate in cross-section and the leading edges thereof are fLared outwardly, and the enlarged portion of the expanding member is tubular with front and rear walls slidable on the mandrel shaft portion, the tubular periphery being slidable in said cylindrical chamber.

Claim 17

Apparatus for setting fasteners having apertures therein, which comprises: a housing, a nose mounted at one end of the housing, said nose including an anvil surface having an aperture therein, a mandrel mounted for reciprocal movement in said housing, means for loading a fastener on the mandrel, means for driving the mandrel through a forward stroke wherein the portion thereof having the fastener loaded thereon extends out the nose, means for expanding the effective cross-section of the end portion of the mandrel beyond that of the fastener aperture after the forward stroke of the mandrel, and means for driving the expanded end of the mandrel toward said anvil surface to set the fastener.

Claim 18

Apparatus for setting fasteners having apertures therein, which comprises: a housing, a nose mounted at one end of the housing, said nose including an anvil surface having an aperture therein, a mandrel mounted for reciprocal movement in said housing, means for loading a fastener on the mandrel, means for driving the mandrel through a forward stroke wherein the portion thereof having the fastener loaded thereon extends out the nose, means for expanding the effective cross-section of the end portion of the mandrel beyond that of the fastener aperture after the forward stroke of the mandrel, and means for driving the expanded end of the mandrel toward said anvil surface to set the fastener.

Claim 19

Apparatus according to claim 15, wherein: said mandrel includes a shaft portion and an enlarged front portion, and said means for expanding the mandrel includes a sleeve mounted for slidable movement on the shaft for movement to and from a position adjacent the thickest part of the enlarged front portion of the mandrel.

Claim 20

Apparatus according to claim 15, wherein said nose includes: a plurality of segments hingedly mounted to the housing, and means for biasing said nose segments to a position wereat they are operable to pass the fastener loaded mandrel therethrough from the housing out, but only to pass the mandrel therethrough into the housing, thus providing the anvil surface for the setting of the fastener.

Claim 21

Apparatus according to claim 15, wherein said means for loading a fastener on the mandrel includes: means for supporting the fastener in said housing wherein the aperture therein is in spaced relationship with the mandrel, and means for gating a fastener onto said support in a timed relationship with the reciprocal movement of the mandrel.

Claim 22

Apparatus according to claim 15, wherein said means for driving said mandrel includes a cylinder provided in said housing, a piston mounted on the mandrel and reciprocal in said cylinder, a spring mounted between the back of the cylinder and the back of the piston for driving a portion of the mandrel out of the nose and means for admitting compressed air into the cylinder in front of the piston to set the fastener on the portion of the mandrel extending out of the nose and drive the mandrel portion back inside the housing.

Claim 23

Apparatus according to claim 16, wherein said means for expanding the mandrel further includes: a tubular member mounted to said sleeve at the rear thereof and slidable along therewith on said mandrel, said tubular member including a front and a back, and a collar mounted on said mandrel and within said tubular member wherein initial driving movement of the mandrel effects the expansion of the end portion of the mandrel since the segmented end of the sleeve moves to said position adjacent the thickest portion thereof and when the collar strikes the rear of the tubular member the thus expanded mandrel is driven back into the fastener.

Claim 24

Apparatus according to claim 6, wherein said mandrel shaft conical portion includes a sharp tip for puncturing apertures in work for the receiving of fasteners therein.

Claim 27

Apparatus according to claim 22, wherein the cross-section of the mandrel shaft is substantially triangular, the flats of the frustoconical portion are generally triangular in shape, the sleeve segments are secant sections of a circle circumscribed about the triangle of the shaft cross-section and the enlarged front portion of the mandrel includes a tapered tip.

Claim 28

Apparatus according to claim 1, wherein the mandrel assembly occupies substantially the entire cross-sectional area of the aperture in the fastener for at least a significant portion of the length thereof when the fastener is placed on the mandrel assembly in its unexpanded mode.

Claim 31

Apparatus according to claim 25, wherein the cross-section of the mandrel shaft is substantially triangular, the sleeve segments are secant sections of a circle circumscribed about the triangle of the shaft cross-section and the enlarged front portion of the mandrel includes a tapered tip.