HK1058167B - A subassembly of a folding tool and the frame member thereof - Google Patents

Description

Folding tool assembly and frame element thereof

Technical Field

The present invention relates to knives and tools and like implements having folding blades or tool heads, and more particularly, to a frame member having a flange that includes an integral leaf spring. The invention also relates to a folding tool assembly having said frame element.

Background

Most folding knives or tools have some form of spring that interacts with the folding blade or tool head to hold the blade or tool head in a folded or extended position relative to the handle. Such springs are normally biased to apply a spring force to the cam-shaped base of the folding blade or tool head. The cam at the bottom is configured so that a greater force is required to move the blade or tool head into or out of the extended or folded position. The spring also applies a frictional force to the base as the blade or tool head moves between the folded and extended positions. For example, conventional pocket knives include a separate back spring that is secured to the frame or side plate of the knife and applies a spring force to the bottom of the blade. The folding utility tools described in U.S. patent nos. 4,238,862, 5,697,114, 5,745,997 and 6,293,018 use a leaf spring integral with a portion of the blade carrier to apply a spring force to the bottom of the blade or tool head. These leaf springs are typically formed by cutting a portion of the frame member, the leaf springs being located within a channel formed by one or more frame members. The multipurpose folding tool described in US5,745,997 comprises one integral leaf spring and two separate beam springs arranged in channel shaped frame members. In US6,014,787 an integral leaf spring is described on the side walls and floor of a channel-shaped frame element.

Disclosure of Invention

It is an object of the present invention to provide a new folding frame member having a flange with an integral leaf spring thereon that does not require significant force to move the blade or tool head into the folded position or out of extension, and a folding tool assembly having such a frame member.

To achieve the above object, the present invention proposes a frame element for use in a folding tool, said frame element comprising a single elongate channel having first and second opposed side walls connected together by an integral channel floor, said channel floor extending along at least a portion of said channel, said side walls having upper and lower edges, said channel floor being connected to said lower edges of said side walls, characterised in that said frame element further comprises an integral first outer flange extending outwardly from said upper edge of said first side wall along at least a portion of said side walls in a first direction away from the channel, said first outer flange extending generally perpendicular to the direction of said first channel side wall and comprising a first integral leaf spring.

The present invention also provides a folding tool assembly comprising:

a. a unitary elongated channel-shaped frame member having first and second spaced apart side walls, a unitary channel floor connecting said side walls together along at least a portion of said channel to form a single channel, said side walls having upper and lower edges, said channel floor being connected to said lower edges of said side walls;

b. a first hinge pin extending from the first channel sidewall in a first direction away from the channel; the method is characterized in that:

c. an elongated integral first outer flange extending outwardly from said upper edge of said first sidewall in said first direction away from said channel, said first outer flange comprising a first integral leaf spring;

d. a first tool bit hingedly mounted outside said passage on said first hinge pin for rotation between a folded position and an extended position, said first leaf spring supported on a base of said first tool bit;

e. a second tool bit hingedly mounted in the channel and rotatable between a collapsed position and an extended position.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

Drawings

FIG. 1 is an isometric view of a folding tool with side panels omitted, the folding tool including a frame member of a first embodiment of the present invention;

FIG. 2 is an isometric view of a folding tool including a frame member according to a second embodiment of the invention;

FIG. 3 is an isometric view of a folding tool including a frame member according to a third embodiment of the invention;

FIGS. 4, 5 and 6 are end, side and isometric views, respectively, of the frame of FIG. 1;

FIGS. 7, 8 and 9 are end, side and isometric views, respectively, of the frame of FIG. 2;

FIGS. 10, 11 and 12 are end, side and isometric views, respectively, of a frame member according to another embodiment of the present invention;

figures 13, 14 and 15 are end, side and isometric views, respectively, of a frame member according to another embodiment of the present invention;

FIGS. 16, 17 and 18 are respectively end, side and isometric views showing the frame of FIG. 3;

FIG. 19 is a side view of a folding tool with side panels omitted, the folding tool including the frame shown in FIGS. 3 and 16-18;

FIGS. 20, 21 and 22 are end, side and isometric views, respectively, of a frame member according to another embodiment of the present invention;

figures 23, 24 and 25 are end, side and isometric views, respectively, of a frame member according to another embodiment of the present invention;

FIG. 26 is an isometric view of a frame member according to another embodiment of the invention;

fig. 27 is an isometric view of a frame member according to another embodiment of the invention.

Detailed Description

Fig. 1 and 4-6 show a first embodiment of a frame element 10. The elongated plate 14 includes an integral elongated partial upper flange 16 and an integral elongated partial lower flange 20. Two flanges extend outwardly from the plate 14 in generally opposite directions, an upper flange 16 extends outwardly in a first direction along a portion of the plate upper edge 18, and a lower flange 20 extends outwardly in a second direction along a portion of the plate lower edge 22. In the illustrated embodiment, the plate 14 is substantially flat, and the flanges 16, 20 are perpendicular to the plate 14. At its outermost end, i.e. adjacent one end of the plate, each of the flanges 16, 20 includes an integral elongate leaf spring 24. The portion of the flange that includes the leaf spring 24 is separated from the adjacent portion of the plate 14 by an elongated slot 26. The lightening holes 33 in the plate 14 reduce the weight of the tool 11 by removing excess material.

Referring to fig. 5 and 6, an opening 28 is included at each end of the plate 14. These openings 28 are provided to receive a hinge pin 30, as shown in the tool 11 of fig. 1, on which a blade or tool head 32 may be hingedly mounted. (the term "tool head" as used herein includes blades, pliers, scissors or other similar implements). When the tool heads 32 are positioned on the frame member 10, the leaf springs 24 associated with the upper and lower flanges 16, 20 apply a spring force to the base 34 of each tool head 32. As shown in fig. 1 and 19, the base 34 of the tool head has a cam shape so that the spring force acting on the base of the tool head can hold the tool head in the folded or extended position. To move between the folded and extended positions, sufficient force must be applied to the tool head 32 to overcome the spring force to bend the spring 24 upwardly in a direction away from the hinge pin 30.

Fig. 1 shows a tool head 32, in this case a leaf spring 24 associated with the partial upper flange 16, in combination with a base 34 of a blade hingedly mounted on the distal side of the plate 14 by means of a hinge pin 30. As shown in fig. 19, the end of the spring 24 is provided with a shoulder against which a step on the bottom 34 of the tool head 32 can abut, preventing further rotation of the tool head and providing axial support for the blade. A second tool bit 32, a screwdriver, is hingedly mounted on the proximal side of the plate 14 by hinge pin 30. The leaf spring 24 associated with the lower flange 20 engages the bottom 34 of the screwdriver.

Side plates 36 as shown in fig. 2 and 3 may be attached to the tool assembly shown in fig. 1 by hinge pins 30 to form tool slots facing away from each other for receiving folding tool bits. In fig. 1, the downwardly facing tool pocket on the distal side of plate 14 is defined by plate 14, the distal side plate, and the partial upper flange 16 with spring 24. The tool head 32 may be stored in this slot and may be rotated downwardly out of the slot to a position of extension toward one end of the plate. Likewise, the upwardly facing tool slot on the proximal side of the plate is made up of the proximal side plate, the plate 14 and the partial lower flange 20 with the leaf spring 24. A screwdriver may be received in this tool slot and may be rotated upwardly away from the tool slot towards an extended position at the other end of the plate.

FIGS. 10-12 show frame members similar to those of FIGS. 1 and 4-6. The embodiment of figures 10 to 12 however includes a full upper flange 17 extending along the entire upper edge of the plate 14. The full upper flange 17 comprises a second leaf spring 24, said second leaf spring 24 being located at the end of the flange opposite to the first leaf spring 24. The second leaf spring 24 allows an additional tool head to be positioned proximally of the plate. Although only a single tool bit interacting with a dedicated leaf spring is shown, a single spring may engage more than one tool bit.

Figures 7 to 9 show another embodiment of the frame element. This embodiment comprises a full upper flange 17 with a leaf spring at both ends and a full lower flange 21 with a leaf spring 24 at both ends, ensuring that tool bits 32 are arranged on both ends on both sides of the plate. The tool 12 shown in fig. 2 includes the frame elements shown in fig. 7-9, and further includes a tool head 32, a hinge pin 30, and a side plate 36. The side plate 36 cooperates with the flanges 17, 21, the spring 24 and the plate 14 to form two tool slots 38, the two tool slots 38 being located on either side of the plate. The proximal tool recess faces downward and the tool head 32 can be rotated downward from one end of the tool away from the tool recess 38. The distal tool slot faces upward and the two tool heads 32 can be rotated upward from one end of the tool away from the tool slot 38. It can also be seen from fig. 2 that the tool heads 32 on the same end can be rotated in opposite directions, as can the tool heads in the same tool slots.

Fig. 13-15 show another embodiment of a frame member similar to that shown in fig. 10-12, except that the frame member of this embodiment includes a center leaf spring 40 associated with the partial lower flange 20. The central leaf spring 40 is located at the inner end of the partial lower flange, i.e. adjacent the middle of the plate 14, and does not extend from the end of the flange adjacent the plate end. The intermediate leaf spring 40 facilitates the mounting of an intermediate tool head, not shown, such as a corkscrew or awl, which is typically used in an extended position perpendicular to the direction of orientation of the board. A central aperture 42 in the plate 14 is capable of receiving a hinge pin about which the intermediate tool head is capable of rotating between the folded and extended positions.

As can be seen from the end views of the frame members in fig. 4,7, 10 and 13, the frames shown in fig. 1, 2 and 4-16 are all "Z-shaped" in that the plate 14 is centrally disposed and the upper and lower flanges 16, 17, 20 and 21 extend outwardly from the upper and lower edges of the two sides of the plate to secure the articulating tool head 32 to the two sides of the plate. The flanges may extend only along a partial length of the upper edge 18 or the lower edge 22 of the panel as shown in figure 6, may extend along the entire length of the panel as shown in figure 9, or may extend along partial and entire lengths of the panel at the upper and lower edges of the panel as shown in figures 12-14 and 15-17, respectively. The leaf springs may be located at the ends of the flanges adjacent the ends of the plates or at one end of the flanges towards the middle of the plates as shown in figures 15 to 17. These embodiments of the Z-shaped frame member are only intended to illustrate the invention and other embodiments not shown are also within the scope of the invention as defined by the claims.

Fig. 16-19 show a different type of frame element, in other words a channel shaped frame element with an outer flange. Referring first to fig. 16-19, the channel-shaped frame member 44 includes an integral full outer flange 46 extending outwardly along an upper edge of the plate 50a and a partial inner flange 48 extending outwardly from a lower edge of the plate 50a in a direction opposite the flange 46. The inner flange 48 is integral with the plates 50a and 50b facing each other and connects the plates 50a and 50b together. The integral outer flange includes two leaf springs 24 located at each end of the flange. As described above and shown in fig. 19, these leaf springs 24 apply a spring force to the cam-shaped bottom 34 of the tool head 32, said bottom 34 being hinged to the frame element 44 by means of the hinge pin 30 arranged in the opening 28. As can be seen in fig. 16 and 18, frame member 44 possesses a channel shape in which plates 50a and 50b are used as channel walls and partial flange 48 is used as a channel floor. The channel-shaped frame member 44 defines an upwardly facing interior tool pocket 52 within the channel. This inner tool recess 52 can be seen in the lower shank of the tool 13 shown in fig. 3. The addition of side plates to the frame member shown in fig. 16-19 will form a second downwardly facing outer tool pocket for receiving a tool head 32 such as shown in fig. 19.

Referring to fig. 27, the channel-shaped frame member 44 has an integral partial outer flange 66 and an integral partial inner flange 48. The partial inner flange includes an inner leaf spring 64 arranged to interact with a tool bit stored in the inner tool pocket 52, while the leaf spring 24 of the partial outer flange is arranged to interact with a tool bit carried on the other side of the plate 50a and stored in the outer tool pocket.

The partial inner flange 48 shown in figures 16 to 18 and 26 interacts with a tool head stored in an inner tool slot and is able to pivot at the right hand end of the frame member 44 about a hinge pin, not shown, using a separate spring similar to that described in US5,745,997.

Figure 3 shows a folding utility tool including a channel shaped frame member having an outer flange as shown and described in figures 16-19. In this case, folding scissors tool 13 comprises two handles 60a and 60b, each having frame member 44 as described above. Referring to the lower handle 60a shown in fig. 3, the side plate 36 does not allow one to see the plate 50a, but instead sees the full outer flange 46 extending outwardly from the plate 50 a. The plate 50b with the lightening holes in the tool groove 52 can be clearly seen. The tool head 32 is in a folded condition within the outer tool channel. Leaf springs 24 at the scissor ends of the handles engage the base 34 of the tool head 32. When tool 13 is fully folded, one of scissor blades 56 is received within inner tool channel 52.

The handle can be understood in detail from a view of the upper handle 60 b. The tool head 32 is located in the outer tool pocket. A partial internal flange 48 is seen, two independent springs 62 located within the channel and arranged to apply a spring force to the base 34 of the scissor blade 56.

The frame embodiment shown in fig. 16-19 is shown in the two-handled scissors tool 13 shown in fig. 3, but it may also be used in a single-handled tool such as that shown in fig. 1 and 2.

In the embodiment shown in FIGS. 3, 16-19 and 26, the inner flange 48 does not extend the entire length of the opposed plates 50a and 50b, and the separate spring shown in FIG. 3 is used to apply a spring force to the base 34 of the scissors blade 56. However, as shown in fig. 27, an internal leaf spring 64 may also be used to interact with a folding tool head located within the channel formed by channel-shaped frame member 44. The inner leaf spring 64 may be used alone or in combination with a separate spring. The inner flange 48 may extend along the length of the frame member 44 and may comprise more than one leaf spring, one at each end of the flange, and act on a tool bit, for example. Likewise, separate springs may apply spring forces at both ends of the channel-shaped frame member to a tool head hingedly mounted in the inner tool pocket. For example, although the local inner flanges 48 are shown at one end of the channel, they could be located centrally of the channel as in our co-pending application serial No. 09/703,369, leaving room for individual springs to act at both ends of the channel. As with the Z-shaped frame member described, the channel shaped frame member with external flanges may be configured in a variety of forms, and these other forms are not shown.

FIGS. 20-26 show an embodiment of a channel-shaped frame member having two outer flanges. Referring first to the particular embodiment shown in fig. 20-22, the elongated channel-shaped frame member 70a includes a full outer upper flange 72 extending outwardly from the upper edge of side plate 50b, a partial inner flange 74 connected to side plates 50a and 50b, and a partial outer flange 76 extending outwardly from side plate 50 a. All portions of the frame member 70a are integral with one another. The full outer flange 72 includes two inner leaf springs 24 located at each end of the flange. Each of the leaf springs 24 is capable of interacting with at least a base portion 34 of one of the tool bits 32. The frame member 70a defines an upwardly facing tool pocket capable of receiving a tool bit which is rotatable about a hinge pin extending between the two side plates 50a and 50b and within the apertures 28 at the ends of the frame. As noted above, these tool bits may be biased by an internal leaf spring as shown in FIG. 27 or by a separate spring 62 as shown in FIG. 3. The partial outer upper flange 76 includes a single leaf spring 24 at the outer end of the elongated flange. This spring is capable of interacting with the bottom of at least one tool head. The addition of these side plates, not shown in the drawings, to the frame member 70a results in two downwardly facing outer tool channels on either side of the plate and one upwardly facing tool channel.

Referring to fig. 23-25, an elongated channel-shaped frame member 70b includes a first full outer upper flange 72 extending outwardly from an upper edge of the plate 50b, a partial inner flange extending outwardly from a lower edge of the plate 50b, the partial flange connecting the plate 50b to the plate 50 a. A second fully outer upper flange 72 extends outwardly from the upper edge of the plate 50 a. The addition of a side plate to the frame member 70b again creates two downwardly facing outer tool channels, and in addition to this, the frame of this embodiment also includes a second leaf spring 24 on a second full outer upper flange 72, ensuring that at least one other folding tool head is mounted in the outer tool channel adjacent the side plate 50 a.

FIG. 26 is another view of the frame member 70a shown in FIGS. 20-22 having a full outer upper flange 72 and a partial outer upper flange 76 extending outwardly from the side plate 50a, the flange 72 not being shown and extending outwardly from the side plate 50 b. The orientation of the frame member 70a shown in fig. 26 allows one to clearly see the bottom of the frame member and shows how the partial inner flanges 74 extend outwardly from the side panels 50a and 50b in a direction substantially opposite the flanges 72 and join the side panels 50a and 50b together. Although the channel frames 44, 70a and 70b are shown as having a partial inner flange, tools having a full inner flange are also within the scope of the present invention.

In the preferred embodiment shown, the frame elements 10, 44, 70a and 70b are made by bending sheet metal to form the plates and flanges and cutting to form the leaf springs. In the embodiment shown the flanges extend substantially outwardly in a direction perpendicular to the plate, but this arrangement is not essential and other configurations may be used. Also in the described embodiment the plate is planar, but this is not critical for the invention. Also in the described embodiment the plate and the flange are parallel, but this is not essential. Furthermore, it is not necessary to have springs at both ends of the full flange. The spring does not necessarily have to act on the bottom of the blade. For example, a frame member having full flanges and springs at both ends of the flanges may have a tool head 32 associated with one flange and coupled to the other spring by a washer. Although the illustrated embodiment shows the spring 24 bending downwardly towards the frame, the spring does not necessarily have to be preloaded in this manner.

The invention has been described in considerable detail, so that various alterations and modifications will become apparent to others skilled in the art upon the reading and understanding of this specification. All such changes and modifications are intended to be included herein within the scope of the present invention and protected by the following claims.

Claims (32)

1. A frame element for use in a folding tool, the frame element comprising a single elongate channel (44, 70a, 70b), the channel having first and second opposed side walls (50a, 50b) joined together by an integral channel floor (48, 74), said channel floor (48, 74) extending along at least a portion of said channel, said side walls having upper and lower edges, said channel floor being connected to said lower edges of said side walls, characterized in that said frame member further comprises an integral first outer flange (46, 66, 72, 76) extending outwardly from said upper edge of said first side wall along at least a portion of said side wall in a first direction away from the channel, the first outer flange extends generally perpendicular to the direction of the first channel side wall (50a, 50b) and includes a first integral leaf spring (24).

2. The frame element of claim 1, wherein: the first and second side walls (50a, 50b) are substantially parallel.

3. The frame element of claim 1, wherein: the channel floor includes an integral leaf spring (64).

4. The frame element of claim 1, wherein: further included is an integral second outer flange (66, 72, 76) extending outwardly from the upper edge of the second sidewall (50a, 50b) in a second direction opposite the first direction away from the channel, the second outer flange including an integral leaf spring (24).

5. The frame element according to claim 1, characterized in that it is intended for a folding tool of the type having a first and a second folding tool head (32) rotatable between a folded and an extended position, the first integral leaf spring (24) being supportable at the bottom (34) of the first folding tool head.

6. The frame element of claim 1, wherein: the first outer flange (46, 72) has first and second ends, the first integral leaf spring (24) is located at the first end of the first outer flange, and the first outer flange further includes a second leaf spring located at the second end of the first outer flange.

7. The frame element of claim 5, wherein: the first side wall (50a, 50b) includes a first opening (28) configured to receive a first hinge pin (30) about which the first and second tool bits (32) may rotate.

8. The frame element of claim 5, wherein: the first outer flange (46, 72) has first and second ends, the first integral leaf spring (24) is located at the first end, the first outer flange further includes a second leaf spring located at the second end, the first side wall (50a, 50b) includes first and second openings (28) configured to receive first and second hinge pins (30), about which the first and second tool bits (32) may rotate, respectively.

9. The frame element of claim 8, wherein: the first and second openings (28) are disposed adjacent the first and second leaf springs to ensure that the leaf springs engage the tool bit.

10. The frame element of claim 1, wherein: the first sidewall (50a, 50b) has a first side and a second side, the first sidewall (50a, 50b) and the first outer flange (46, 66, 72, 76) define a first tool receiving area (38) at the first side of the first sidewall (50a, 50b), and the first and second sidewalls (50a, 50b) and the channel floor (48, 74) define a second tool receiving area (52) at the second side of the first sidewall (50a, 50 b).

11. The frame element of claim 5, wherein: the first and second side walls (50a, 50b) each have a first opening (28) aligned with one another to receive a common hinge pin (30) about which the first and second tool bits (32) can rotate.

12. The frame element of claim 1, wherein: the first outer flange (46, 66, 72, 76) defines a plane substantially perpendicular to the first channel sidewall (50a, 50b), the leaf spring (24) lying substantially in the plane.

13. The frame element of claim 1, wherein: a portion of the first outer flange (46, 66, 72, 76) includes the first leaf spring (24) separated from an adjacent portion of the first channel side wall (50a, 50b) by a separate cutout, the first leaf spring formed by removing material from the unitary frame element at the cutout.

14. The frame element according to claim 13, wherein: the cut-out is located substantially in the first channel side wall (50a, 50 b).

15. The frame element according to claim 13, wherein: the cut-out is substantially planar.

16. The frame element of claim 14, wherein: the cutout is substantially parallel to a plane defined by the first outer flange (46, 66, 72, 76).

17. A folding tool assembly comprising:

a. a unitary elongated channel-shaped frame member having first and second spaced apart side walls (50a, 50b), an integral channel floor connecting said side walls together along at least a portion of said channel to form a single channel (44, 70a, 70b), said side walls having upper and lower edges, said channel floor being connected to said lower edges of said side walls;

b. a first hinge pin (30) projecting from the first channel sidewall (50a, 50b) in a first direction away from the channel; the method is characterized in that:

c. an elongated integral first outer flange (46, 66, 72, 76) extending outwardly from said upper edge of said first sidewall in said first direction away from said channel, said first outer flange comprising a first integral leaf spring;

d. a first tool bit (32) hingedly mounted outside said passage on said first hinge pin for rotation between a folded position and an extended position, said first leaf spring supported on a base (34) of said first tool bit;

e. a second tool head (32) is hingedly mounted in the passageway and is rotatable between a collapsed position and an extended position.

18. The assembly of claim 17, wherein: the first hinge pin (30) also extends into the channel (44, 70a, 70b), the second tool bit (32) being hingedly mounted on the first hinge pin.

19. The assembly of claim 17, wherein: further comprising a second hinge pin (30) extending into the passage, the second tool bit (32) being hingedly mounted on the second hinge pin.

20. The assembly of claim 17, wherein: the channel floor (48, 74) includes an integral leaf spring (64).

21. The assembly of claim 20, wherein: a leaf spring (64) on the channel floor (48) bears on the bottom (34) of the second tool head (32).

22. The assembly of claim 17, wherein: also included is a separate spring (62) located within the channel that is not integral with the channel (44, 70a, 70b) and that bears against the base (34) of the second tool bit (32).

23. The assembly of claim 17, including a spring located within the channel, the spring bearing on a base (34) of the second tool head (32).

24. The assembly of claim 18, wherein: further included is an elongated integral second outer flange (66, 72, 76) extending outwardly from the upper edge of the second side wall (50a, 50b) in a second direction away from the channel, the second outer flange including a first integral leaf spring (24), a third tool head (32) hingedly mounted outside the channel, the leaf spring associated with the second flange bearing on a bottom portion (34) of the third tool head.

25. The assembly of claim 17, wherein: a first side plate (36) not integral with the frame element is disposed adjacent the first outer flange (46, 66, 72, 76) to form a first outer tool slot (38) located outside the channel (44, 70a, 70b), the first outer tool slot being defined by the first side wall (50a, 50b), the first outer flange, and the first side plate (36).

26. The assembly of claim 25, wherein: an internal tool pocket (52) located in the channel (44, 70a, 70b) is defined by the first and second sidewalls (50a, 50b) and the channel floor (48, 74).

27. The assembly of claim 26, wherein: the first outer tool pocket (38) has an opening facing in a first direction and the inner tool pocket (52) has an opening facing in a second direction, the second direction being opposite the first direction.

28. The assembly of claim 25, wherein: an integral second outer flange (72, 76) extending outwardly from the upper edge of the second channel wall (50a, 50b) in a second direction away from the channel (70a, 70b), the second outer flange comprising: an integral leaf spring (24) and a second side plate (36), the second side plate (36) being disposed non-integral with the frame element adjacent the second outer flange (66, 72, 76) to form a second outer tool pocket (38) defined by the second side wall (50a, 50b), the second outer flange and the second side plate (36).

29. The assembly of claim 17, wherein: the leaf springs (24) are formed by removing material at individual cuts of the unitary frame element.

30. The assembly of claim 29, wherein: the cut-out is located substantially in the first channel side wall (50a, 50 b).

31. The assembly of claim 30, wherein: the cut-out is substantially planar.

32. The assembly of claim 17, wherein: the first outer flange (46, 66, 72, 76) defines a plane substantially perpendicular to the first channel sidewall (50a, 50b) in which the integral leaf spring (24) lies.