GB2173761A - Fastener assemblies - Google Patents

Abstract

A fastener assembly comprising a plurality of elongate fastener elements 21 secured together with mutually parallel longitudinal axes by means of at least one plastics retaining strip 22 engaged with the elements (21), each fastener element 21 having a workpiece-entering end and a head, characterised in that said strip comprises a plurality of first portions 22a penetrated by the respective fastener elements 21, each first portion 22a having an outer diameter at least as large as the diameter of the head 20 of the associated fastener, and the first portions 22a being secured together by respective second portions 26 so dimensioned and formed as to fracture when a predetermined driving impact is applied to the head of said associated fastener so that the respective first portion 22a remains engaged with the respective fastener (21). This ensures that the individual fasteners will be accurately guided in the driving channel of a driving tool during driving. <IMAGE>

Description

SPECIFICATION Fastener assemblies The present invention relates to fastener assemblies, and is applicable, inter alia, to nail strips comprising nails for insertion by a fastener driving apparatus into dense materials such as concrete, stone or steel.

In a fastener driving apparatus for insertion ofthe fastener into the workpiece with a single blow, it is necessary for the channel through which the fastener is driven to have a diameter equal to or greaterthan the widest portion of the fastener. For fasteners such as nails, the driver striking end, i.e. the head, is usual lygreaterin diameter than the shank portion.

Since the driver channel must be as large asthe head, the workpiece-entering end, i.e. the point, may shift awayfrom the longitudinal axis ofthe driver channel during driving and therefore entering the workpiecewith an inclined orientation ratherthan perpendicularto the workpiece. With rough construction nails, inclined driving is of little significance and in some applications such as "toe nailing", it is even desirable. However, it is essential to have the fastener enter perpendicular when driving into concrete, stone, steel andthelikewherethenail has a great chance of bending or deflecting if it strikes these dense materials at an angle.

An object of this invention is to provide a fastener assembly which enables fasteners to be driven therefrom through a driving channel whilst reliably maintaining the axes ofthefasteners substantially parallel to the axis of the driving channel.

According to one aspect of the invention, there is provided a fastener assembly comprising a plurality of elongate fastener elements secured together with mutually parallel longitudinal axes by means ofa retaining strip engaged with the elements, each fastener element having a workpiece-entering end and a head, characterised in that said strip comprises a plurality offirst portions penetrated by the respective fastener elements, each first portion having an outer diameter at least as large as the diameter of the head ofthe associated fastener, and the first portions being secured together by respective second portions so dimensioned and formed as to fracture when a prede termined driving impact is applied to the head of said associated fastener so that the respective first portion remains engaged with the respective fastener.

According to a further aspect of the invention, there is provided a method of driving a fastener element from an assembly according to said one aspect along a drive channel by striking the fastener element on its head to displace the element transversely of the assembly and detach it therefrom, characterised in that the fastener element passes along said drive channel whilst being guided at least partially by slid- ing contact between the associated first portion and a wall of said driving channel.

According to another aspect of the invention, there is provided a method of manufacturing a fastener assembly accordi ng to said one aspect in which the first portions ofthe retaining strip are moulded direct lyaboutthe respective fastener elements.

For a better understanding ofthe invention, and to show howthe same may be carried into effect, referencewill now be made, byway ofexample, to the accompanying drawings, in which: Figure lisa view of the nail strip in a tool readyfor driving; Figure2 is a side view ofthe nail strip; Figure3 is a plan view of the nail strip; Figure 4 is a cross-sectional view along line A-A of Figure2; FigureS is a cross-sectional view along line B-B of Figure3; Figure 6is a sideviewof a nail shorterthan in Figure 2 with guide covering the point of the nail; Figure 7isthesame as Figure 5 of shorter nails; Figure8showsthenail being driven throughanail driving apparatus into a workpiece;; Figure 9 shows a short nail with a small head and the guide portion acting asthe onlyguiding means; Figure 10 shows a nail with a small head with two guide portions acting as the guide to hold the nail axis straight during driving; and Figure 11 shows a deformation on the nail shankto provide a better bond to a guide member.

Figures 1 and 2 show a first embodiment offastener assembly in the form of a nail clip 15. This clip can be inserted into a nail driving apparatus 16 having a driving channel 17 in which is mounted a reciprocable driver 18. The driver 18 is given reciprocal sliding movement by a conventional piston and valving means. The head 20 of each fastener, here a nail 19, moves forward alon a deliverytrack 25, which is part ofthe apparatus, into the driving channel 17. The driver 18 forces the leading nail 19 out of channel 17 into the workpiece 30 each time the apparatus is cycled, the nail 19 thus being transversely detached from clip 15.

The nail clip 15 is constructed with the heads 20 substantially in a straight line with the shank portions 21 parallel. A retaining member or strip 22 of pliable plastics material is moulded around each shank portion 21 intermediate the head 20 and theworkpiece entering point 23. The strip 22 is moulded in a configuration having respective major portions forming guide members 22a encircling the shank portions and having an outer diameter substantiallythe same as thatofthe head 20 ofthe nail 19. For ease of handling, a second strip 24 may be attached to the shank portions 21 between the strip 22 and the heads 20 to provide stabilityto the clip 15.

Figures 3 and 4showthe strip 22 in cross-section having respective guide members 22a encompassing the shank21 and having a substantially circular outer surface. A minor portion 26 of each guide member is integral withthe adjoining guidemembersoasto form the continuous strip 22. The strip is given a convenient length to form the clip 15. The length will depend on the type of driving apparatus 16 in which the nail clip 15 isto be used.

As the leading nail 19 is forced transversely from the clip 15, the associated minor portion 26 will fractureallowing the guide memberto be transported along with the nail 19through the driving channel 17.

Since the guide member22a is a close fit in thedriv ing channel 17, the point 23 ofthe nail 19will be maintained on the axis of the driving channel 17 as the nail passes through. The head 20 ofthe nail 19 is also substantiallythe same size and therefore the axis ofthe nail 19 remains parallel to the axis ofthe drive channel 17 to ensure that the nail 19 enters thework- piece perpendicularly when the apparatus 16 is positioned properly for driving.

The driving action is illustrated in Figure 8. As the guide member 22a moves downward through the drive channel 17, the lower surface contacts a workpiece 30 which stops the movementofthe guide member 22a. The nail 19 continues downward breaking the bond between the nail 19 and the guide member22a, i.e. producing mutual sliding. The guide member 22a nowfunctions as a bore through which the nail shank portion 21 is guided. As the top surface ofthe guide member 22a is contacted by head 20, it is crushed and split underthe driving force and istherefore ejected from the drive channel 17. After the driver 18 returnsto the "at rest" position, the next nail is fed into position for the next cycle.

Referring nowto Figures 2 and 5, each guide member 22a is shown encompassing a portion ofthe point 23 of the nail 19. The minor portion 26 used to interconnect the guide members 22a is considerably smal- ler in cross-sectional area and therefore requires a lesserforce to cause fracture thereof than that necessary to force the shank portion 21 through the major portion forming the guide member 22a. The guide member 22 will remain locked to the shank portion 21 until the bottom surface contacts the workpiece 30.

Figures 6 and 7 showthe guide member 22a positioned to enclose or covertotallythe points 23. This effect may be produced depending on the method of collation and the location ofthe guide member 22 in relation to the head 20. The lengths of the nails 19 themselves vary in the manufacturing thereof, but it is not significant whether the points 23 are totally enclosed or protruding as regards the driving ofthe nail. Of course, enclosing ofthe points has advantages in safety and ease of handling.

When the retaining strip 22 is located near the point 23, a secondary strip 24 may be necessary ordesirable to supportthe nails 19 in a stable manner. Such second strip 24 may be of any suitable size and shape and may be applied to the nails in any suitable manner. The top and bottom surfaces ofthe moulded retaining strip 22 may have also an irregularshape35 as shown in Figures 5 and 7 caused by the configuration of the moulding wheel in which the retaining strip 22 is formed.

Figure 9 shows a shortertype of nail 28 having a head 29 of smaller diameter. A guide member 31 is provided having a cross-sectional size corresponding to the driving channel ofthe tool, i.e. widerthan the head 29. Since the head 29 does not act as a guide, the guide member31 needs sufficient length, in relation to the nail length, to keep the nail axis parallel to that ofthe drive channel 17 during the driving movement there-through, e.g. at least 1/3 of the shank length.

Minor portions 26 ofthe retaining strip function the same as described above in respectofthe other embodiments.

Figure 10 shows a relatively long nail 32 having a head 33 smallerthan the drive channel 17 through which itwill be driven. In this case, one row of guide members 22a may not be sufficientto ensure thatthe axis of the nail 32 will remain parallel to that of the drive channel 17. Therefore a second row 34 is moulded onto the shanks having substantiallythe same cross-secional size as thefirst guide members 22.

Referring now to Figure 11, each guide member 22a may be located above the point 23 and yet function on the same as previously described. The shank 21 may be provided with shallow recesses 36 (knurled region) so asto provide a surface that will give a better bond to the guide member 22 than could be obtained with a smooth shank.

Therecesses36can betransverse, longitudinal or on an incline. Adequate bonding is achieved provided the bond between the shank21 and the guide member 22a does not break before the minor portion 26, interconnecting the guide members 22a, fractures when aforce is exerted on the head 20.

Thus preferably the guide members 22 remain immovably affixed to the nails until the guide members strike the workpiece during driving.

Although the present invention has been described with reference to certain illustrative embodiments thereof, it should be understood that other modifications can be readily devised by those skilled in the art that will fall within the scope of this invention.

Claims (15)

1. Afastener assembly comprising a plurality of elongate fastener elements (21) secured together with mutually parallel longitudinal axes by means of a retaining strip (22) engaged with the elements (21), each fastener element (21) having a workpieceentering end and a head, characterised in that said strip comprises a plurality offirst portions (22a) penetrated bytherespectivefastenerelements (21), each first portion (22a) having an outer diameter at least as large as the diameterofthe head (20,29,33) ofthe associated fastener, and the first portions (22a) being secured together by respective second portions (26) so dimensioned and formed as to fracture when a predetermined driving impact is applied to the head of said associated fastener so thatthe respectivefirst portion (22a) remains engaged with the respective fastener (21).

2. An assembly according to claim 1 wherein each first portion (22a) hs an outer diameter substantially equal to that ofthe associated fastener head (20,29, 33).

3. An assembly according to claim 1 wherein each first portion (22a) has an outer diameter substantially largerthan that of the associated fastener head (20, 29,33).

4. An assembly according to any one of claims 1 to 3 wherein a further strip (24,34) is provided to engage said fastener elements.

5. An assembly according to claim 4wherein said further strip (34) comprises a plurality ofthird portions penetrated by respective fastener elements (21), each third portion having an outer diameter at least as large as the diameter ofthe head (20,29,33) of the associated fastener, and the third portions being secured together by respective fourth portions so dimensioned and formed astofracturewhen said predetermined driving impact is applied to the head of said associated fastener so that the respective third portion remains engaged with the respective fastener.

6. An assembly according to any one of claims 1 to 3 wherein each first portion has a length equal to at least one third ofthe length of the associated fastener.

7. An assembly according to any one ofthe preceding claims wherein each said first portion encloses the workpiece-entering end of the associated fastener element (21).

8. An assembly according to any one of the preceding claims wherein each fastener element (21) is provided with grooves on its surface region engaged by the respective first portion (22a).

9. Afastener assembly substantially as hereinbefore described with reference to, and/or as illustrated in, Figures 1 to 5, or Figures 6 and 7, or Figure 9, or Figure 10 or Figure 11 ofthe accompanying drawings.

10. A method of driving a fastener elementfrom an assembly according to any one of the preceding claims along a drive channel by striking the fastener element on its head to displace the element transversely of the assembly and detach it therefrom, characterised in that the fastener element passes along said drive channel whilst being guided at least partially by sliding contact between the associated first portion (22a) and a wall of said driving channel.

11. A method according to claim 10 in which said element is guided both by said first portion and by the head thereof.

12. A method according to claim 10 orI 1 in which the fastener element strikes and enters a workpiece to initiate relative sliding between the fastener element and the first portion until the head ofthefastener strikes the first portion.

13. A method according to claim 12 inwhichcon- tact between said first portion and said head causes crushing and ejection of said first portion.

14. A method of driving a fastener element substantially as hereinbefore described with reference to, and/or as illustrated in, Figures 1 and 8 ofthe accompanying darwings.

15. A method of manufacturing a fastener assem blyaccording to any one of claims 1 to 9 in which the first portions (22a) of the retaining strip are moulded directly about the respective fastener elements (21).