IMPROVEMENTS IN OR RELATING TO FASTENING DEVICES
TECHNICAL FIELD
This invention relates to fastening devices of the kind comprising an elongate magazine to carry a series of gapped fasteners bendable to close the gap, and bending mechanism having a pair of opposed press heads at an end of the magazine co-operable to bend each fastener following the feeding of each fastener from the magazine to an interhead position and the passage of parts to be joined into the fastener through the gap. The bendable gapped fasteners usually consist of short lengths of wire of generally C, U or like shape.
BACKGROUND ART
In the usual fastening device of this kind the fastener in its interhead position extends transversely of the direction of feed, with the gap in close proximity to the end of the magazine. Consequently, there arises the serious disadvantage that passage of the parts to be joined into the fastener through the gap tends to be obstructed by the closely adjacent magazine.
DISCLOSURE OF INVENTION
The object of the present invention is to overcome said disadvantage.
According to the present invention in a fastening device of the aforesaid kind the press heads are co-operable to rotate the fastener from a first interhead position in which it extends transversely of the direction of feed with its gap adjacent to the magazine, to a second interhead pos ition in which it extends in the general direction of feed with its gap remote from
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the magazine. Thus, with the fastener in this second interhead position, passage of the parts to be joined into the fastener through the gap is greatly facilitated. In one form of the invention, a press head includes a wedge face which during an initial closing movement of the heads- relative to one another engages with the fastener to rotate same to the second interhead position. In another form of the invention a press head is rotatable and is capable of coupling with the fastener during an initial closing movement of the heads relative to one another, so that rotation of the fastener to the second interhead position is effected by successively coupling the head to the fastener and rotating the head.
BRIEF DESCRIPTION OF DRAWINGS
Reference is now made to the accompanying diagrammatic drawings, in which:Fig. 1 is a side view of a fastening hand-plier loaded with fasteners.
Fig. 1A is a cross-sectional view on the line A-A of Fig. 1.
Fig. IB is a side view of the fastener of Figs. 1 and 1A.
Figs.2 and 3 are respectively fragmentary end and plan views of a press head of the plier.
Fig. 4 is an end view showing both press heads of the plier. Fig. 5 is a top perspective view of a rudimentary press head illustrating the function thereof.
Figs. 6, 7 and 8 are respectively side, end, and sectional plan views of the press head of Fig. 5 at an end of the magazine of the plier.
Fig. 9 is a side view of a modified fastener.
Fig. 10 is a cross-sectional view of a magazine in which the modified fastener of Fig. 9 is slidingly mounted. Fig. 11 is a diagrammatic part-sectional side view of a fastening machine.
Fig. 12 is a top plan view of the machine of Fig. 11.
Fig. 13 is a fragmentary top perspective view of the machine of Fig. 11.
BEST MODE OF CARRYING OUT THE INVENTION Referring to Figs. 1 to 10 of the drawings:- A fastening hand-plier is designed to bend fasteners 11 consisting of generally C-shaped lengths of wire so as to close the gap 11G in the fastener and form, a ring of generally triangular shape binding together parts previously passed into the fastener through the gap 11 G. The plier consists of an elongate magazine 1 of generally C-section corresponding to the shape of the fasteners 11 to accommodate slidingly a strip of fasteners, and bending mechanism including an arm 2 pivotally mounted on the base of the magazine 1 at 3 to provide in combination with the magazine a pair of handles 4 and 5 and a pair of jaws 6 and 7, and a pair of press heads 8 and 9 on the respective jaws at the outer ends thereof. A leaf spring (not shown) between the hand les 4 and 5 urges the hand les apart to ma intain the jaws 6 and 7 in fully open position in which a nose 10 on the arm 5 engages the magazine 1. The fasteners 11 in integral strip form are slidingly mounted in the magazine 1 and are fed forwards in the magazine by a spring-urged pusher (not shown).
The press head 9 on the jaw 7 includes guide means consisting of a flange 13 which is an integral extension of the base 12 of the jaw 7 , and an inwardly projecting V-section stop 14 on the flange 13 forming with the flange a support for engagement with the stem 15 of the leading fastener 11 fed from the magazine, said support permitting combined transverse and rotational movement of the stem 15. The press head 9 further includes a longitudinal groove 16, and this groove together with a longitudinal groove
17 in the flat face 8A of the press head 8 are intended to accommodate respectively fastener arms 18 and 19 at opposite ends of the stem. The press head 9 still further includes a wedge face 20 which slopes forwards and transversely outwards from the inner face of the side wall 21 of the jaw 7 and has an edge co-incident with the longitudinal edge 16A of the groove 16.
With the plier ready for use (Fig. 1), the leading fastener 11 is in a first interhead position, that is, in a plane at right angles to the direction of feed F. In operation of the plier, with an initial slight squeezing together of the handles 4 and 5, the face 8A of the head 8 breaks the leading fastener 11 off the strip and forces the arm 18 of the fastener against the wedge face 20 of the head 9 whereby the jaws 6 and 7 close slightly and a combined translational and rotational movement is imparted to the fastener which turns through 90 to a second interhead position viz. in a plane extending in the direction of feed F with the gap 11 G remote from the magazine 1. The plier is then manipulated to cause the parts to be secured to pass into the fastener through the gap 11 G. Thereupon the handles are subjected to a further squeezing action to close the jaws 6 and 7 further and cause the heads 8 and 9 to bend
the fastener and thereby close the gap and form an approximately triangular ring securing the parts together. On releasing the handles 4 and 5 the jaws 6 and 7 spring open and the pliers are then easily manipulated clear of the ring, whereupon the next fastener is fed forward to the first interhead position for engagement by the press heads.
By virtue of the invention, a slight initial squeezing of the hand-gripped plier is sufficient to effect rotation of the fastener through 90° and thereby position the gap well clear of the end of the magazine so that the parts to be joined can be passed easily through the gap without previous manipulation of the plier involving wrist action and finger-gripping of the plier. The plier can therefore be used efficiently for long periods without the. operator suffering muscular tiredness.
It will readily be appreciated that the present invention is not applicable solely to fastenging pliers wherein one of the pivotal members constitutes the elongate magazine for the fasteners . Clearly the present invention is applicable to any hand-operable fastening plier wherein the fasteners pass from a magazine to an interhead position at an end of the magazine.
MODIFICATION OF THE INVENTION
In an advantageous modification shown in Figs. and 10, the fastener 11A with the gap 11G has the stem 15A bent to an outwardly projecting shallow V with an apex 22. With this shape the fastener is more easily bent to ring form by the press heads. As shown in Fig. 10, an elongate magazine 1A for the fasteners 11A has a cross-sectional shape
corresponding to the shape of the fasteners which are slidingly mounted in the magazine.
Referring to Figs. 11 to 13, a U-frame 23 has on the base 24 thereof an elongate magazine 25 slidingly accommodating a strip of fasteners of C-shaped wire, and has on the opposed arms 26 and 27 thereof press heads 28 and 29 disposed at the discharge end of the magazine 25. The head 28 is mounted for rotation about a vertical axis and for vertical reciprocation. A slot 30 in the head 28 is shaped to conform to the upper portion of the fastener and provides for coupling of the head with the fastener when the fastener is in a first interhead position with the gap close to the magazine. A groove 31 in the head 29 is shaped to conform to the lower postion of the fastener when the fastener is in a second interhead position with the gap clear of the magazine.
The head 28 is carried by a vertical cylindrical shaft 32 rotatable and reciprocable in the arm 26. The shaft 32 is supported against downward movement by a compression spring 33 in a chamber 34 in the arm 26 , and against rotary movement by a tension spring 35 maintaining a radial pin 36 on the shaft against a stop rod 37. A horizontally reciprocable cam bar 38 co-operates with formations on the upper end portion of the shaft 32 to impart to the shaft, against spring action, the axial and rotary movements required to cause the head 28 firstly to break off the fastener and then, in co-operation with the head 29, to couple with the fastener, rotate the fastener through 90 , and bend the fastener to generally triangular ring form. Thus, during the operative stroke of the cam bar 38 in the direction A, a pair of wedge faces 39 and 40 respectively on the cam bar 38 and the shaft
32 co-operate to move the shaft downwards, and a pair of flats 41 and 42 co-operate to retain the shaft in its lowered position while a nose 43 on the cam bar engages eccentrically a vertical face 44 on the shaft to rotate the shaft until the face 44 thereon abuts the side face 45 of the cam bar. The fastener has thus been rotated through 90 to a second interhead position with the gap clear of the magazine. After this initial operation, the parts to be joined are inserted into the fastener through the ideally positioned gap, whereupon movement of the cam bar, is continued so that wedge faces 46 and 47 interengage to move the shaft 32 downwards and thereby cause the heads to bend the fastener to ring form, the downward movement of the shaft 32 terminating on engagementof a flat 48 on the cam bar with the flat 42 on the shaft 32. On retraction of the cam bar, the shaft 32 is restored to its initial position by the springs 33 and 35.
INDUSTRIAL APPLICAB ILITY Fastening devices in accordance with the invention have a wide f ield of use , and are espec ially useful for securing together s ide-by-s ide wire lengths , for example , in mattress and upholstery work involving wire springs , and in the erection of wire-net fenc ing .