US20040118720A1

US20040118720A1 - Fastener carrier assembly and method of use

Info

Publication number: US20040118720A1
Application number: US10/321,840
Authority: US
Inventors: Jeffrey Powers; Paul Gaudron
Original assignee: Powers Fasteners Inc
Current assignee: Black and Decker Inc
Priority date: 2002-12-18
Filing date: 2002-12-18
Publication date: 2004-06-24

Abstract

A fastener carrier assembly used to secure rows of fasteners in a workpiece using a conventional driving tool. The fastener carrier assembly includes a plurality of fasteners, an upper strip and a separate lower strip. The upper strips include a plurality of interconnected, frangible collating elements. The lower strip includes sleeves that are intended to stay with the fastener after the fastener is embedded into a workpiece.

Description

The invention relates generally to a fastener carrier assembly and method of use for securing fasteners in a workpiece using a driving tool, such as a nail gun.

BACKGROUND OF THE INVENTION

Fastener carrier assemblies for securing rows of fasteners in a driving tool such as a nail gun are known, as in U.S. Pat. No. 6,394,268. This patent discloses a single strip of interconnected collar members disposed upon a plurality of fasteners within a driving gun. In U.S. Pat. No. 5,931,622, fasteners are maintained in position by a single strip of carrier sleeves that include breakable portions which detach from the fasteners as each fastener is driven into a workpiece. In U.S. Pat. No. 5,069,340, a single strip of fastener sleeves includes an annular portion formed with a breakable portion. The annular portion is intended for being kept with the fastener after it has been driven into a workpiece and the breakable portion is intended for removal from the annular portion after the fastener has been driven into the workpiece.

It would be desirable to have a fastener carrier assembly that includes a first, frangible carrier portion which collates a plurality of fasteners and a second carrier portion that stays with the fastener after it has been driven into a workpiece, but which reliably maintains its structural integrity after the fastener has been driven into a workpiece and/or which may be fashioned in various ways, such as a washer and/or structural damper, without imposing design constraints on the first carrier portion. It would also be desirable to have a carrier assembly that allows one to replace a second part of a carrier strip intended to stay with a fastener with a different second part that is better suited for a particular application, without affecting or causing to replace or re-design a first frangible carrier strip that collates the fasteners. It would further be desirable that such a generally two-piece carrier assembly would be cost-efficient to manufacture and capable of providing all of the collating functions necessary for proper functioning in standard driving tools, but without compromising the aforementioned attributes relating to a two-piece design.

SUMMARY OF THE INVENTION

The above needs are met, and the shortcomings of prior art are overcome by the fastener carrier assembly of the invention. In particular, the invention provides a fastener carrier assembly of the type used to secure rows of fasteners using a driving tool, wherein the fastener carrier assembly includes a first and second carrier portion. The first carrier portion is removed from a fastener as it is being driven into a workpiece and the second carrier portion remains with the embedded fastener.

According to one embodiment, a fastener carrier assembly includes a plurality of drivable fasteners, an upper strip and a plurality of washers which may be interconnected. The upper strips include a plurality of interconnected, frangible collating elements attached in a row. The collating elements and washers are secured to the fastener shanks and spaced from each other such that the collating elements are disposed near the fastener head and the washers are disposed near the fastener tip. The collating elements may be made of the same material, or a different material from the washers, and one or both of the collating elements and washers may have the same widthwise extent as the diameter of the fastener head.

In another embodiment, a carrier assembly adapted for collating fasteners for use with a driving tool includes a plurality of frangible collating elements and sleeves, each pair of which being disposed at respective upper and lower portions of a fastener shank, wherein each sleeve is adapted for being lodged between the respective fastener head and workpiece when the fastener is embedded in the workpiece. The sleeves may correspond to washers having a torus shape, or the sleeves may describe some other geometric body which is generally axially symmetric. The collating elements may have a first cross section that is substantially thinner than a second section, so as to promote fracture of the collating element along a predetermined line. The sleeves may be made from a relatively elastic material, while at the same time the collating elements may be made from a more brittle material.

In another embodiment, a method for securing fasteners to a workpiece includes the steps of providing a fastener carrier assembly including a plurality of securing members and interconnected collating members secured to each fastener, inserting the fastener carrier assembly into a magazine of a driving tool having a firing bore, advancing each of the fasteners into the firing bore, and discharging the driving tool. As each one of the fasteners is driven into the workpiece, the collating element is broken off and fully removed from the fastener. After the collating element has been fully removed from the fastener, the washer advances upwardly along the shank until the fastener has been driven to its final depth in the workpiece.

Additional features and advantages of the invention will be set forth or be apparent from the description that follows The features and advantages of the invention will be realized and attained by the structures and methods particularly pointed out in the written description and claims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation without limiting the scope of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings: [0010]
FIG. 1[0011] a is an isometric view of one embodiment of a fastener carrier assembly incorporating the principles of the invention.
FIG. 1[0012] b is a side view of the fastener assembly of FIG. 1b.
FIG. 2[0013] a is a plan view of a portion of an upper carrier strip of the fastener assembly of FIG. 1a.
FIG. 2[0014] b is a side view of the upper carrier strip portion of FIG. 2a.
FIG. 3[0015] a is a top view of a portion of a lower carrier strip of the fastener assembly of FIG. 1 a.
FIG. 3[0016] b is a side view of the lower carrier strip portion of FIG. 3a.
FIGS. 4[0017] a through 4 c are side views of a representative fastener being driven into a workpiece according to the principles of invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A fastener carrier assembly of the invention includes a plurality of fasteners, an upper carrier portion and a lower carrier portion. A preferred embodiment of the fastener assembly is illustrated in FIGS. 1[0018] a-1 b. The fasteners, which have drivable heads, e.g., nails or pins, are collated by one or both of the carrier portions so that they may be driven into a workpiece using any conventional pneumatic or combustion powered driving tool. The carrier portions include respective upper and lower sleeves which grip the fasteners at positions along the fasteners' shanks. When located within the driving tool's magazine, the carrier portions promote proper alignment of the fasteners as they are advanced within the magazine, and then positioned within the nose of the driving tool. When in the nose of the driving tool, a fastener is driven into the base material (or workpiece) by the tool's driving mechanism, which will typically both separate the fastener from the row of remaining fasteners and apply a driving force to the fastener head. As the fastener is driven into the base material, the upper sleeve is removed from the shank while the lower sleeve remains with the fastener. Thus, after the fastener has been driven into the workpiece, the lower sleeve remains lodged between the workpiece and head of the fastener.
One example of a fastener assembly incorporating the principles of invention is illustrated in FIGS. 1[0019] a-3 b. In this embodiment, a fastener carrier assembly 10 includes a plurality of nail-type fasteners 20, collated by two separate upper and lower carrier strips 30 and 50.
Referring to FIGS. 1[0020] a and 1 b, each fastener 20 includes a drivable head 22 and an elongated shank 24. Shank 24 includes a taper 25 formed at its upper end near head 22 and a pointed tip 29 at its lower end adapted for piercing through a workpiece, such as wood, drywall, metal, concrete or a combination thereof. In the disclosed embodiment, fastener 20 is adapted for being driven into concrete-like material. Fastener head 22 and shank 24 are suitably sized for use in any conventional pneumatic or combustion driving tool, such as the Trakfast driving tool. In the disclosed embodiment, shank 24 is of circular cross-section. Each fastener 20 is made from material of suitable strength, e.g., high strength steel. Strip 30 includes a plurality of upper sleeves 32 connected by upper frangible bridges 34. Sleeves 32 are preferably positioned to grip fasteners 20 at upper portions 26 of their respective shanks 24.
[0021] Lower carrier strip 50 is separate and spaced apart from upper strip 30. Strip 50 includes a plurality of lower sleeves 52 which may be interconnected by frangible lower bridges 54. Sleeves 32 are preferably positioned to grip fasteners 20 at lower portions 28 of their respective shanks 24.
Each of [0022] sleeves 30 and 50 are preferably manufactured from the same material, e.g., high density polyethylene. Carrier assembly 10 may be assembled by inserting fasteners 20 into preformed strips 30 and 50, or carrier assembly 10 may be assembled by directly molding carrier strips 30 and 50 onto a row of fasteners. In the former case, the holes formed by each sleeve of strips 30 and 50 may be sized for snugly receiving a respective fastener so that inadvertent removal of fasteners 20 from strips 30 and 50 during normal handling activities (e.g., assembly, packaging, and loading) is minimized.
As can be seen in FIG. 1[0023] b, each of an upper sleeve 32 and lower sleeve 52 of strips 30 and 50, respectively, may have a lateral extent d that is approximately equal to a diameter of head 22. By sizing the lengths of sleeves 32 and 52 according to head 22 diameter, fastener 20 will tend to maintain proper alignment within the driving bore of the driving tool nose when impacted by the driving mechanism. This is because head 22, sleeve 32, and in particular sleeve 52 will bear against the walls of the bore before any substantial misalignment occurs within the bore. Such a sizing of sleeves according to head 22 diameter may also minimize the extent that one fastener may rotate relative to other fasteners when in a tool's magazine, without a need to stiffen bridges 34 and/or 54 since the ends of adjacent sleeves 52 will abut before fastener 20 rotates a significant amount.
FIGS. 2[0024] a and 2 b illustrate respective top and side views of upper sleeve 32., Sleeve 32 is formed so as to provide adequate strength for maintaining proper alignment of fasteners 20 as carrier assembly 10 is fed through the magazine of the driving tool, yet is easily breakable and removable from fastener 20 as fastener 20 is driven into a workpiece by the tool's driving mechanism. Upper sleeve 32 may have a polygonal outer surface 33 including straight-edged side portions 32 c and 32 d, and end portions 32 a and 32 b to achieve this purpose. A preformed, circular hole 36 extends through sleeve 32 and preferably has a diameter sized to achieve a firm grip of fastener 20 about upper portion 26. Chamfers 38 and 42 may also be formed along one or both of openings 38 and 42 to assist with guiding fasteners into sleeve 32 during assembly of carrier assembly 10.
[0025] Side portions 32 c and 32 d are preferably sized to provide a relatively thin cross-section for sleeve 32, as compared to end portions 32 a and 32 b. More specifically, the thickness of side portions 32 c and 32 d, as best illustrated in FIG. 2a, are sufficiently thin so that sleeve 32 will fail at one or both of portions 32 c and 32 d when fastener 20 is driven into the workpiece. Frangible bridges 34 are formed between adjoining end portions 32 a and 32 b of sleeves 32 so as to retain sleeves and fasteners in the desired collated fashion. Bridges 34 may be sized to provide sufficient structural support to keep upper sleeves 32 connected during normal handling activities (e.g., assembly, packaging, and loading), but also to permit rapid and easy separation of sleeve 32 from adjoining sleeves during the fastener driving process.
Referring to FIG. 2[0026] b, first and second surfaces 44 and 46 of sleeve 32 are preferably substantially flat. However, notches may be formed along the upper surface of side portions 32 c and 32 d to encourage fracture at pre-designated areas of sleeve 32. As discussed in greater detail below, when fastener 20 is driven into the base material, sleeve 32 will fail at one or both of portions 32 c and 32 d due to opposed compressive forces of lower sleeve 50 and head 22, and outwardly directed forces exerted on inner walls of hole 36 by taper 25 as sleeve 30 is forced into head 22.
FIGS. 3[0027] a and 3 b illustrate respective top and side views of lower sleeve 52. Unlike sleeve 32, lower sleeve 52 is intended to remain with fastener 20 after fastener 20 has been driven into the workpiece. In the preferred embodiment, sleeve 52 resembles a torus, but may take on various other shapes, e.g., a shape defined by an elliptical, rather than circular, cross section, or a cylindrical cross section. As mentioned above, the lateral extent of sleeve 52 may approximate the outer diameter d of fastener head 22 to assist with maintaining proper co-axial alignment of fastener in the bore of the driving tool nose, and/or to maintain proper alignment between fasteners 20.
[0028] Lower sleeve 52 has a preformed circular-like hole 56, which preferably has a diameter that achieves a firm grip of fastener 20 about lower portion 28 of fastener shank 24 when shank 24 is inserted into hole 56 during assembly. A tighter fit between shank 24 and hole 56 may be achieved by, e.g., forming a boss 68 along a wall of hole 56, thereby increasing the elastic holding forces in sleeve 52 as shank 24 is forced through undersized hole 56. Referring to FIG. 3b, sleeve 52 preferably includes substantially flat upper and lower surfaces 64, 66, circumscribing openings 58, 62 of hole 56. In other embodiments, sleeve 52 may have a protruding flange formed along the upper and/or lower surfaces that is adapted for being flattened out as sleeve 52 is squeezed between head 22 and the workpiece. A protruding flange may be desired for purposes of minimizing movement between a fixture and fastener 20, such as when fastener 20 cannot be fully driven into the workpiece.
[0029] Sleeves 52 may be interconnected by frangible bridges 54, as shown. Bridges 34 and 54 may have a comparable length and cross section, and they may be made from the same material. However, it may be desirable to have detached sleeves 52, or sleeves 52 which are connected by bridges 54 having reduced strength properties as compared to bridges 34. Such a need may arise if, e.g., there is concern that the bridge connecting sleeves 52 is not cut at essentially the same time as upper bridge 34, thereby inducing a twisting moment when the fastener is acted upon by the driving mechanism.
[0030] Fasteners 20 may be used to secure fixtures, such as furring strips or channels, to a base material such as a concrete wall. FIGS. 4a, 4 b and 4 c illustrate the sequence of events from fastener 20 being impacted by the driving mechanism to fastener 20 being embedded into a concrete base material 70 for purposes of retaining, e.g., a metal fixture 72 to the concrete. Referring to FIG. 4a, a blow is applied to head 22 at surface 23 by the driving mechanism (illustrated as externally applied force F). Sleeves 32 and 52 are severed from connecting sleeves, either by the shear stress induced across the bridges by force F, and/or by providing a cutting blade in the driving mechanism which is applied to bridges 34 and 54 simultaneously with F. As mentioned above, sleeve 52 may, or may not be interconnected by a bridge, but it is preferred that sleeve 52 is interconnected by a bridge.
After [0031] fastener 20 has begun to penetrate fixture 72 and base 70, sleeve 52 is pushed upwards along shank 24, mates with sleeve 32 and then pushes sleeve 32 into taper 25. Referring to FIG. 4b, as sleeve 32 is forced into contact with taper 25 and head 22, the combined compressive forces of head 20 and sleeve 52, and outwardly directed forces exerted upon sleeve 32 by taper 25 cause sleeve 32 to break off from fastener 20 by failure along one or both of side portions 32 c and 32 d (as illustrated by sleeve pieces 74 and 76). Lower sleeve 52 is preferably significantly less prone to fracture than upper sleeve 32 since it is intended to stay with fastener 20. At least for this reason, sleeve 52 is preferably shaped to be axially symmetric to minimize stress concentrations that may result during the fastener driving process.
FIG. 4[0032] c illustrates a final position of fastener 20. As shown, a compressed or uncompressed sleeve 78 is lodged between head 22 and fixture 72. In some instances, fastener 20 fails to be completely driven into the workpiece, such as where an impervious rock is disposed in the concrete, or a tool simply does not have sufficient driving force to fully drive fastener 20 into the workpiece. In such situations, a gap 80 forms, which allows an undesirable freedom of motion between head 22 and base 70. For example, gap 80 may lead to relatively high airborne and/or mechanical noise transmission as fixture 72 is allowed to vibrate due to the gap, or gap may ultimately lead to fastener 20 being removed from workpiece 70 by repeated vibration of fixture 72. In either case, the presence of sleeve 78 lodged between head 22 and fixture 72 may assist with absorbing the vibration energy transmitted between fastener 20 and fixture 72. As such, sleeve 54 may alternatively be thought of as a dampening structure.
As mentioned above, in the [0033] preferred embodiment sleeves 32 and 52 are made from the same material. However, in an alternative embodiment, sleeve 52 may be made from a more elastic material than sleeve 32. A more elastic sleeve 52 may enhance its dampening function when lodged between a fixture 72 and the fastener head 22. In this sense, the invention provides leeway for such alternative designs, i.e., composite carrier assembly, because the upper and lower strips 30 and 50 are separate pieces. On the one hand, upper sleeve 32, which is intended to be broken away, may be so designed to enhance or improve upon the repeatability of its fracture regions for each fastener 20 when acted upon by the tool's driving mechanism, but without compromising the function of lower sleeve 52, which is intended to stay with fastener 20 and act as a load-bearing component thereof. On the other hand, if it is desired to use a material for sleeve 52 which, e.g., has a higher damping coefficient, such a design may be implemented without affecting the function of sleeve 32.
Although the foregoing description is directed to the preferred embodiments of the invention, it is noted that other variations and modifications will be apparent to those skilled in the art, and may be made without departing from the spirit or scope of the invention. [0034]

Claims

What is claimed is:

1. A fastener carrier assembly of the type used with a driving tool, comprising:

a plurality of fasteners, each of which including a drivable head and an elongated shank terminating at a tip;

an upper strip including a plurality of interconnected, frangible collating elements, each of which being connected to a respective shank at a location proximal the head; and

a plurality of washers, each of which being connected to a respective shank at a location proximal the tip and spaced from a respective collating element.

2. The fastener carrier assembly of claim 1, wherein the plurality of washers are interconnected to each other by frangible bridges.

3. The fastener carrier assembly of claim 1, wherein each of the shanks have a longitudinal axis and each of the respective washers connected to the shanks describe a shape that is essentially axially symmetrical about the longitudinal axis.

4. The fastener carrier assembly of claim 3, wherein each of the collating elements describe a polygonal shape having a first and second thickness when viewed in a plane that is perpendicular to the longitudinal axis.

5. The fastener carrier assembly of claim 1, wherein the fasteners are one of pins and nails.

6. A two-piece carrier assembly adapted for holding a plurality of fasteners, the carrier assembly being of the type used with a driving tool, wherein each of the fasteners include a drivable head and an elongated shank terminating at a tip, and each of the fasteners are drivable into a workpiece by the driving tool, the two-piece carrier assembly comprising:

a lower strip including a plurality of sleeves, each of which being connected to a respective shank at a location proximal the tip, spaced from a respective collating element and adapted for being lodged between the respective fastener head and workpiece when the fastener is fully embedded in the workpiece.

7. The carrier assembly of claim 6, wherein each of the sleeves describe a first, asymmetric shape when viewed in a plane perpendicular to the shank longitudinal axis, and each of the collating elements describe a second, symmetric shape when viewed in the plane.

8. A method for securing fasteners to a workpiece, comprising the steps of:

providing a fastener carrier assembly including a plurality of fasteners, each of which having a head, shank and a tip, a plurality of securing members disposed near the tip of each of the respective fasteners, and a separate, upper strip including a plurality of collating members, each of which gripping a fastener at a location between the securing member and the head;

inserting the fastener carrier assembly into a magazine of a driving tool, the driving tool having a firing bore;

advancing each of the fasteners into the firing bore; and

discharging the gun, wherein as each one of the fasteners is driven into the workpiece by the gun, the upper sleeve is broken off and fully removed from the fastener, and after the upper sleeve has been fully removed from the fastener, the lower sleeve advances upwardly along the shank until the fastener has been driven to its final depth in the workpiece.

9. A method for securing fasteners to a workpiece as in claim 8, wherein the providing step further includes providing a plurality of interconnected securing members.

10. A method for securing fasteners to a workpiece as in claim 8, wherein the providing step further includes providing a plurality of circular shaped securing members.