Electrical test probe having rotational control of the probe shaft

Claim 2

An electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having a hollow interior; a plunger having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point, the plunger also having a hollow elongated receptacle extending into the interior of the barrel, said receptacle having a geometric-shaped pilot hole spaced inwardly from the open end of the barrel; an elongated fixed guide member disposed in the barrel interior and extending through the pilot hole of the receptacle, the guide member extending through the hollow interior of the barrel away from the receptacle of the plunger, the guide member having an outer surface of geometric-shaped cross-sectional configuration engaging the geometric-shaped pilot hole of the receptacle; and spring means inside the barrel, extending along the length of the guide member, and biased against a portion of the receptacle inside the barrel, so that axial travel of the plunger and its receptacle is against the bias of the spring means, the geometric-shaped outer surface of the guide member engaging the geometric-shaped pilot hole of the receptacle so that normal relative rotation between the pilot hole and the geometric-shaped outer surface of the guide member is resisted, while said spring bias causes said axial travel for controlling rotation of the plunger about its axis as the receptacle of the plunger travels axially relative to the guide member into the interior of the barrel against the bias of the spring means.

Claim 3

Apparatus according to claim 1 in which the geometric-shaped outer surface portion of the guide member is of helical configuration, so that a force applied to the plunger causing the plunger to travel into the barrel against the bias of the spring means causes the plunger to rotate about its axis, said rotation being controlled by engagement of the pilot hole of the receptacle traveling along the helical configuration of the guide member.

Claim 4

Apparatus according to claim 1 in which axial plunger travel relative to the guide member is linear and non-rotational.

Claim 5

Apparatus according to claim 1 in which the cooperating geometric shapes of the pilot hole and the outer surface of the guide member are of polygon configuration.

Claim 6

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of the plunger travel; a plunger disposed in the barrel and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point, the plunger also having a bearing portion disposed within the interior of the barrel; and spring means disposed in the barrel and biased against the bearing portion of the plunger for supporting the plunger within the barrel by spring pressure, so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the barrel having a relatively short wall portion of reduced diameter cross section which is deformed around the plunger with inwardly projecting control surfaces forming sides of a polygon-shaped pilot hole in the barrel wall surrounding and elongated with the plunger; the plunger having an elongated control surface of helical configuration with an axial pitch and a polygon-shaped cross section matching the polygon-shaped cross section of the pilot hole, the plunger control surface being engaged with said pilot hole in the barrel so that pressure applied to the plunger against the bias of the spring means causes the control surface of the plunger to travel axially relative to the pilot hole in a direction against the bias of the spring means, the polygon-shaped pilot hole cooperating with the polygon-shaped control shaped pilot hole cooperating with the polygon-shaped control surface for causing rotation of the plunger about its axis as the plunger travels axially into the barrel against the bias of the spring means for rotating the contact tip during its contact with the test point.

Claim 7

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of the plunger travel; a plunger disposed in the barrel and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point, the plunger also having a bearing portion disposed within the interior of the barrel; and spring means disposed in the barrel and biased against the bearing portion of the plunger for supporting the plunger within the barrel by spring pressure, so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the barrel having a relatively short wall portion of reduced diameter cross section which is deformed around the plunger with inwardly projecting control surfaces forming sides of a polygon-shaped pilot hole in the barrel wall surrounding and elongated with the plunger; the plunger having an elongated control surface of helical configuration with an axial pitch and a polygon-shaped cross section matching the polygon-shaped cross section of the pilot hole, the plunger control surface being engaged with said pilot hole in the barrel so that pressure applied to the plunger against the bias of the spring means causes the control surface of the plunger to travel axially relative to the pilot hole in a direction against the bias of the spring means, the polygon-shaped pilot hole cooperating with the polygon-shaped control shaped pilot hole cooperating with the polygon-shaped control surface for causing rotation of the plunger about its axis as the plunger travels axially into the barrel against the bias of the spring means for rotating the contact tip during its contact with the test point.

Claim 8

Apparatus according to claim 5 in which the pilot hole is square, and the plunger is square in cross section and is twisted on its axis to form the helical pitch of the control surface.

Claim 9

Apparatus according to claim 5 in which the pilot hole is formed on a short end portion of the barrel.

Claim 10

Apparatus according to claim 5 in which the polygon shapes of the pilot hole and plunger control surface are square.

Claim 11

Apparatus according to claim 5 in which the polygon shapes of the pilot hole and plunger control surface are triangular.

Claim 12

Apparatus according to claim 5 in which the wall of the barrel is deformed with generally flat control surfaces spaced apart around the pilot hole axis to define the sides of the polygon-shaped pilot hole, in which the flat control surfaces on the barrel are deforned inwardly into engagement with corresponding surfaces of the helical control surface on the plunger to form said matching polygon-shaped cross sections

Claim 13

Apparatus according to claim 5 in which the pilot hole is square, and in which the plunger is square in cross section and is twisted on its axis to form the helical pitch of the control surface.

Claim 14

Apparatus according to claim 5 in which the pilot hole is triangular, and in which the plunger is triangular in cross section and is twisted on its axis to form the helical pitch of the control surface.

Claim 15

Apparatus according to claim 5 in which the length of the deformed portion of the barrel wall is substantially shorter than the length of a complete axial revolution of the helical control surface on the plunger.

Claim 16

An electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having a hollow interior; a plunger having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point, the plunger also having a hollow elongated receptacle extending into the interior of the barrel, said receptacle having a square-shaped pilot hole spaced inwardly from the open end of the barrel; an elongated fixed guide member disposed in the barrel interior and extending through the pilot hole of the receptacle, the guide member extending through the hollow interior of the barrel away from the receptacle of the plunger, the guide member having an outer surface of square-shaped cross-sectional configuration engaging the square-shaped pilot hole of the receptacle; and spring means inside the barrel, extending along the length of the guide member, and biased against an internal end of the receptacle inside the barrel, so that axial travel of the plunger and its receptacle is against the bias of the spring means, the square-shaped outer surface of the guide member engaging the pilot hole of the receptacle for controlling rotation of the plunger about its axis as the receptacle of the plunger travels axially relative to the guide member into the interior of the barrel against he bias of the spring means.

Claim 17

An electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having a hollow interior; a plunger having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point, the plunger also having a hollow elongated receptacle extending into the interior of the barrel, said receptacle having a square-shaped pilot hole spaced inwardly from the open end of the barrel; an elongated fixed guide member disposed in the barrel interior and extending through the pilot hole of the receptacle, the guide member extending through the hollow interior of the barrel away from the receptacle of the plunger, the guide member having an outer surface of square-shaped cross-sectional configuration engaging the square-shaped pilot hole of the receptacle; and spring means inside the barrel, extending along the length of the guide member, and biased against an internal end of the receptacle inside the barrel, so that axial travel of the plunger and its receptacle is against the bias of the spring means, the square-shaped outer surface of the guide member engaging the pilot hole of the receptacle for controlling rotation of the plunger about its axis as the receptacle of the plunger travels axially relative to the guide member into the interior of the barrel against he bias of the spring means.

Claim 18

Apparatus according to claim 14 in which the square-shaped outer surface portion of the guide member is of helical configuration, so that a force applied to the plunger causing the plunger to travel axially into the barrel against the bias of the spring means causes the plunger to rotate about its axis, said rotation being controlled by engagement of the pilot hole of the receptacle traveling along the helical configuration in the guide member.

Claim 19

Apparatus according to claim 14 in which axial plunger travel relative to the guide member is linear and non-rotational.

Claim 20

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel for travel along said axis and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with the test point, the plunger also having an internal portion disposed within the interior of the barrel; and spring means disposed in the barrel and biased against the internal portion of the plunger for supporting the plunger within the barrel by spring pressure, so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the barrel being deformed as a relatively short tubular wall portion of reduced diameter cross section with inwardly projecting, generally flat control surfaces forming generally flat sides of a geometric-shaped pilot hole in the barrel wall surrounding the plunger and engaged with an elongated control surface on the plunger, the plunger control surface having a helical configuration with an axial pitch for causing the plunger to rotate about its axis during axial travel of the helical control surface through the fixed pilot hole of the barrel, for thereby rotating the contact tip for enhancing frictional contact between the contact tip and the test point of the unit under test.

Claim 21

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel for travel along said axis and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with the test point, the plunger also having an internal portion disposed within the interior of the barrel; and spring means disposed in the barrel and biased against the internal portion of the plunger for supporting the plunger within the barrel by spring pressure, so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the barrel being deformed as a relatively short tubular wall portion of reduced diameter cross section with inwardly projecting, generally flat control surfaces forming generally flat sides of a geometric-shaped pilot hole in the barrel wall surrounding the plunger and engaged with an elongated control surface on the plunger, the plunger control surface having a helical configuration with an axial pitch for causing the plunger to rotate about its axis during axial travel of the helical control surface through the fixed pilot hole of the barrel, for thereby rotating the contact tip for enhancing frictional contact between the contact tip and the test point of the unit under test.

Claim 22

Apparatus according to claim 17 in which the geometric shapes of the pilot hole and the control surface of the barrel wall are square.

Claim 23

Apparatus according to claim 17 in which the geometric shapes of the pilot hole and the control surface of the barrel wall are triangular.

Claim 24

Apparatus according to claim 17 in which the pilot hole is square, and the plunger is square in cross section and twisted on its axis to form the helical pitch of the control surface.

Claim 25

Apparatus according to claim 17 in which the helical control surface is on an exterior portion of the plunger, and the pilot hole is in a fixed position in an end portion of the barrel spaced axially from the internal portion of the plunger which contacts the spring means.

Claim 26

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe assembly comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel for travel along said axis and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point on a unit under test, the plunger also having a bearing portion slidably disposed within the interior of the barrel; and spring means disposed in the barrel and biased against the bearing portion of the plunger for supporting the plunger within the barrel by spring pressure, so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the tubular barrel having a relatively short wall portion of reduced diameter cross section which is deformed around the plunger with inwardly projecting control surfaces forming a geometric-shaped pilot hole in the barrel wall surrounding and engaged with the plunger; the plunger having an elongated control surface of helical configuration with an axial pitch engaged with said pilot hole in the barrel wall, the helical control surface of the plunger having a geometric-shaped cross section matching the geometric-shaped cross section of the pilot hole on the barrel so that normal relative rotation between the geometric-shaped plunger control surface and the pilot hole is resisted, while axial pressure applied to the plunger against the bias of the spring means causes the control surface of the plunger to travel axially in the barrel relative to the pilot hole and in a direction against the bias of the spring means, with the geometric-shaped pilot hole engaging the geometric-shaped control surface to thereby cause the plunger to rotate about its axis as the plunger travels axially into the barrel to apply a twisting action between the contact tip of the plunger and the test point on the unit under test.

Claim 27

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe assembly comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel for travel along said axis and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point on a unit under test, the plunger also having a bearing portion slidably disposed within the interior of the barrel; and spring means disposed in the barrel and biased against the bearing portion of the plunger for supporting the plunger within the barrel by spring pressure, so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the tubular barrel having a relatively short wall portion of reduced diameter cross section which is deformed around the plunger with inwardly projecting control surfaces forming a geometric-shaped pilot hole in the barrel wall surrounding and engaged with the plunger; the plunger having an elongated control surface of helical configuration with an axial pitch engaged with said pilot hole in the barrel wall, the helical control surface of the plunger having a geometric-shaped cross section matching the geometric-shaped cross section of the pilot hole on the barrel so that normal relative rotation between the geometric-shaped plunger control surface and the pilot hole is resisted, while axial pressure applied to the plunger against the bias of the spring means causes the control surface of the plunger to travel axially in the barrel relative to the pilot hole and in a direction against the bias of the spring means, with the geometric-shaped pilot hole engaging the geometric-shaped control surface to thereby cause the plunger to rotate about its axis as the plunger travels axially into the barrel to apply a twisting action between the contact tip of the plunger and the test point on the unit under test.

Claim 28

Apparatus according to claim 22 in which the geometric shapes of the pilot hole and control surface on the plunger are of polygon configuration.

Claim 29

Apparatus according to claim 23 in which the polygon shapes are square.

Claim 30

Apparatus according to claim 23 in which the polygon shapes are triangular.

Claim 31

Apparatus according to claim 22 in which the pilot hole is formed on an end portion of the barrel and is spaced axially from the bearing portion of the plunger.

Claim 32

Apparatus according to claim 22 in which the wall of the barrel is deformed with generally flat control surfaces surrounding the pilot hole axis.

Claim 33

Apparatus according to claim 27 in which the flat control surfaces are elongated with a short axial twist matching the helical shape of the plunger control surface.

Claim 34

Apparatus according to claim 22 in which the pilot hole is square, and in which the plunger is square in cross section and is twisted on its axis to form the helical pitch of the plunger control surface.

Claim 35

Apparatus according to claim 22 in which the pilot hole is triangular, and in which the plunger is triangular in cross section and is twisted on its axis to form the helical pitch of the plunger control surface.

Claim 36

Apparatus according to claim 22 in which the length of the deformed portion of the barrel wall is substantially shorter than the length of a complete axial revolution of the helical control surface on the plunger.

Claim 37

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point; and spring means disposed in the barrel and biased against the plunger for supporting the plunger within the barrel by spring pressure so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the barrel having a relatively short wall portion of reduced diameter cross section which is deformed around the plunger forming a generally triangular-shaped pilot hole with generally flat inwardly projecting control surfaces in the barrel wall surrounding and engaged with the plunger; the plunger having an elongated control surface of helical configuration with an axial pitch engaged with said pilot hole in the barrel, the helical control surface of the plunger having a generally triangular-shaped cross section matching the generally triangular-shaped cross section of the pilot hole on the barrel so that pressure applied to the plunger against the bias of the spring means causes the plunger to travel axially relative to the pilot hole in a direction against the bias of the spring means, the control surfaces of the triangular-shaped pilot hole cooperating with the plunger control surface for causing the plunger to rotate about its axis as the plunger travels axially into the barrel for rotating the contact tip during its contact with the test point.

Claim 38

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point; and spring means disposed in the barrel and biased against the plunger for supporting the plunger within the barrel by spring pressure so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the barrel having a relatively short wall portion of reduced diameter cross section which is deformed around the plunger forming a generally triangular-shaped pilot hole with generally flat inwardly projecting control surfaces in the barrel wall surrounding and engaged with the plunger; the plunger having an elongated control surface of helical configuration with an axial pitch engaged with said pilot hole in the barrel, the helical control surface of the plunger having a generally triangular-shaped cross section matching the generally triangular-shaped cross section of the pilot hole on the barrel so that pressure applied to the plunger against the bias of the spring means causes the plunger to travel axially relative to the pilot hole in a direction against the bias of the spring means, the control surfaces of the triangular-shaped pilot hole cooperating with the plunger control surface for causing the plunger to rotate about its axis as the plunger travels axially into the barrel for rotating the contact tip during its contact with the test point.

Claim 39

Apparatus according to claim 32 in which the pilot hole is formed on an end portion of the barrel.

Claim 40

Apparatus according to claim 32 in which the flat control surfaces of the pilot hole are elongated with a short axial twist matching the helical shape of the plunger control surface.

Claim 41

Apparatus according to claim 32 in which the length of the deformed portion of the barrel wall is substantially shorter than the length of a complete axial revolution of the helical control surface on the plunger.

Claim 42

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel for travel along said axis and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point; and spring means disposed in the barrel interior and biased against the plunger for supporting the plunger within the barrel by spring pressure so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the tubular barrel being deformed as a relatively short wall portion of reduced diameter cross section with inwardly projecting control surfaces forming a geometric-shaped pilot hole in the barrel wall surrounding said axis of plunger travel; the plunger having an elongated control surface of geometric-shaped cross section matching the geometric-shaped cross section of the pilot hole and engaged with the pilot hole in the barrel so that pressure applied to the plunger against the bias of the spring means causes the control surface of the plunger to travel axially relative to the pilot hole in a direction against the bias of the spring means, the geometric-shaped pilot hole cooperating with the control surface on the plunger for resisting rotation of the plunger about its axis during axial travel of the plunger into the barrel for thereby producing controlled linear and non-rotational travel of the plunger axially into and out of the barrel.

Claim 43

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel for travel along said axis and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point; and spring means disposed in the barrel interior and biased against the plunger for supporting the plunger within the barrel by spring pressure so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the tubular barrel being deformed as a relatively short wall portion of reduced diameter cross section with inwardly projecting control surfaces forming a geometric-shaped pilot hole in the barrel wall surrounding said axis of plunger travel; the plunger having an elongated control surface of geometric-shaped cross section matching the geometric-shaped cross section of the pilot hole and engaged with the pilot hole in the barrel so that pressure applied to the plunger against the bias of the spring means causes the control surface of the plunger to travel axially relative to the pilot hole in a direction against the bias of the spring means, the geometric-shaped pilot hole cooperating with the control surface on the plunger for resisting rotation of the plunger about its axis during axial travel of the plunger into the barrel for thereby producing controlled linear and non-rotational travel of the plunger axially into and out of the barrel.

Claim 44

Apparatus according to claim 36 in which the matching geometric shapes are square.

Claim 45

Apparatus according to claim 36 in which the matching geometric shapes are triangular.

Claim 46

Apparatus according to claim 36 in which the wall of the barrel is deformed as a polygon shape with generally flat control surfaces surrounding the pilot hole axis.

Claim 47

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel for travel along said axis and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point; and spring means disposed in the barrel interior and biased against the plunger for supporting the plunger within the barrel by spring pressure so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the tubular barrel being crimped to form inwardly projecting guide detents forming a polygon-shaped pilot hole of the barrel wall surrounding and engaged with the plunger; the plunger having an elongated control surface of helical configuration with an axial pitch engaging the guide detents of the crimped pilot hole wall of the barrel so that pressure applied to the plunger against the bias of the spring means causes the control surface of the plunger to travel axially relative to the fixed pilot hole and engage the guide detents thereof to thereby rotate the plunger about its axis as the plunger travels into the barrel for rotating the contact tip during its contact with the test point on the unit under test.

Claim 48

An elongated electrical test probe assembly for making contact with a test point on a unit under test in an electrical continuity diagnostic test device, the test probe comprising: a barrel having an elongated tubular outer wall surrounding a hollow interior area which extends along an axis of plunger travel; a plunger disposed in the barrel for travel along said axis and having an outer portion extending through an open end of the barrel and terminating in a contact tip outside the barrel for contact with a test point; and spring means disposed in the barrel interior and biased against the plunger for supporting the plunger within the barrel by spring pressure so that axial travel of the plunger into the barrel is against the bias of the spring means; the outer wall of the tubular barrel being crimped to form inwardly projecting guide detents forming a polygon-shaped pilot hole of the barrel wall surrounding and engaged with the plunger; the plunger having an elongated control surface of helical configuration with an axial pitch engaging the guide detents of the crimped pilot hole wall of the barrel so that pressure applied to the plunger against the bias of the spring means causes the control surface of the plunger to travel axially relative to the fixed pilot hole and engage the guide detents thereof to thereby rotate the plunger about its axis as the plunger travels into the barrel for rotating the contact tip during its contact with the test point on the unit under test.

Claim 49

Apparatus according to claim 40 in which the pilot hole is in an end portion of the barrel.

Claim 50

Apparatus according to claim 40 in which the polygon shapes of the plunger control surface and the pilot hole are square.

Claim 51

Apparatus according to claim 40 in which the polygon shapes of the plunger control surface and pilot hole are triangular.

Claim 52

Apparatus according to claim 40 in which the guide detents of the pilot hole comprise generally flat surfaces of polygon configuration with a short axial twist matching the helical configuration of the plunger control surface.

Claim 53

Apparatus according to claim 40 in which the length of the deformed portion of the barrel wall is substantially shorter than the length of a complete axial revolution of the helical control surface on the plunger.

Claim 54

Apparatus according to claim 40 in which the guide detents of the pilot hole comprise generally flat sides of polygon configuration matching the cross-sectional configuration of the plunger control surface.

Claim 55

Apparatus according to claim 5 in which the plunger is of polygon shape in cross section with spiral grooves to form the helical configuration of the plunger control surface, and in which the inwardly projecting control surfaces on the barrel are engaged in the spiral grooves of the plunger control surface.

Claim 56

Apparatus according to claim 17 in which the length of the deformed portion of the barrel wall is substantially shorter than the length of a complete axial revolution of the helical control surface on the plunger.

Claim 57

Apparatus according to claim 17 in which the wall of the barrel is deformed with inwardly projecting control surfaces spaced apart around the pilot hole axis to define the sides of the geometric-shaped pilot hole, and in which the control surfaces on the barrel are deformed inwardly into engagement with corresponding surfaces of the helical control surface on the plunger.

Claim 58

Apparatus according to claim 17 in which the internal portion of the plunger is of polygon shape in cross section with spiral grooves to form the helical configuration of the plunger control surface, and in which the flat control surfaces of the barrel wall are engaged in corresponding spiral grooves formed on the control surface of the plunger.

Claim 59

Apparatus according to claim 22 in which the plunger is of polygon shape in cross section with spiral grooves to form the helical configuration of the plunger control surface, and in which the inwardly projecting control surfaces of the deformed barrel wall are engaged in the spiral grooves of the plunger control surface.

Claim 60

Apparatus according to claim 40 in which the guide detents of the geometric-shaped pilot hole comprise circumferentially spaced-apart, individual control surfaces projecting into the interior of the barrel and engaged with the helical control surface on the plunger.

Claim 61

Apparatus according to claim 40 in which the plunger control surface is of polygon shape in cross section with spiral grooves to form the helical configuration of the plunger control surface, and in which the guide detents on the barrel are engaged in the spiral grooves on the plunger.