US2743517A - Manufacture of hypodermic needles - Google Patents

Description

May 1', 1956 s. J. Evl-:RETT 2,743,517

MANUFACTURE OF HYPODERMIC NEEDLES Filed May 1. 1953 4 sheets-sheet 1 MUM a www" U U J A Horne y May 1, 1956 s. J. EVERETT 2,743,517

MANUFACTURE OF HYPODERMIC NEEDLES Filed May l, 1953 4 Sheets-Sheet 2 Attorney May 1, 1956 s. J. EVERETT 2,743,517

MANUFACTURE OF HYPODERMIC NEEDLES Filed May l, 1955 4 Sheets-Sheet 3 n@ R QM B" A ttor/wy May 1, 1956 Filed May 1, 1953 S. J. EVERETT MANUFACTURE OF HYPODERMIC N EEDLS 4 Sheets-Sheet 4 'i ,M y

Inventor QQMJRQM By A Homey United States Patent O MANUFACTURE F HYPODERMIC NEEDLES Samuel James Everett, Thornton Heath, England, assigner `to S. & R. 3. Everett & Company Limited, Thornton Heath, England, a British company Application May 1, 1953, Serial No. 352,439 Claims priority, application Great Britain May 6, 1952 7 Claims. `(Cl. 29-528) This invention relates to the mounting of hypodermic needles in the mounts whichenable themto be attached to the outlet of a hypodermic syringe, and is particularly concerned with the manufacture of needles and mounts in which a comparatively soft metal bush surrounds the needle where it emerges from the mount and extends a short distancetowards the point of the needle, as described in the specification of British Patent No. 651,605 granted to Samuei I ames Everett.

These needles are usually packed in clips on a metal or plastic card which can be packed in a box or container, preferably of metal; a convenient number for each box is twelve needles mounted on a single card in six clips at either end. These needles have previously been manufactured singly, the soft metal bushes being die-cast, a number at a time, on a single runner, separated intoV individual parts, a needle inserted into each bush, and the whole inserted in the mount and swaged into position individually. In such needles in which the point is formed by grinding the needle away at an angle, a fiat formed on the mount should face radially in the same direction as the face formed by grinding the needle.

The present invention enables a much higher rate of production to be achieved by manufacturing the needles and mounts in batches which conveniently correspond to the number heid in clips at one end of the packing card, which in the example quoted above, would be six. The handling of the parts during manufacturing is reduced, as well as the risk of damaging the needle points.

According to the invention, the complete needles are manufactured in sets or batches and, to keep the needles together in their sets and located relative to each other, so that the complete set is easily handled and' the needles are correctly spaced for tting into the various tools, the soft metal bushes are cast around the needles of a set on a continuous runner from which they are not separated until the needles and mounts are complete.

The number of needles in a set may conveniently be the number required at a time for packing. Thus when the needles are packed in dozens, six in clips on each side of the box, it is convenientv to make the needles in sets of six, and the various stages in the manufacture of a set of six needles is illustrated, by way of example only, in the accompanying drawings in which:

Figure l shows six needles set in a mould in which the metal bushes have been cast on a common runner;

Figure 2 shows the six needles with the bushes round them on a common runner;

Figure 3 shows the runner and needles mounted in a die-nest; f

Figure 4 shows the iirst stamping process;

Figure 5 shows the second stamping process;

Figure 6 shows the itting of the mounts;

Figure 7 shows diagrammatically a six-hammer press;

Figure 8 shows an enlarged detail of Figure 7;

Figure 9 shows a set of spring clips for holding the finished needles; l

Figure 10 shows the needles mounted for inspection;

Figure 1l shows a loading jig open;

, Figure vl2 showsa loading jig closed; and

released a spring 36 causes it to turn to raise the punch Patented May 1, 1956 introduced through the hole 7.. The result is `a runner 8,

from which the six bushes 9 project, surrounding the shafts of the needles 1 which pass right through the bushes and project slightly from the upper surface as seen in Figure 2. AThis is now set in the die-nest shown in Figure 3, consisting of a die-body 10, having six suitably Y spaced cavities 11, in which are die-inserts 12, the tops of which projects above die-body 10. These inserts have a central hole to take the shafts of the needles and are coned at the top as shown at 13, so as to form a sharp edge round the ring of a diameter rather greater than the diameter of the metal bushes 9. This die-nest with the runner and needles in place, is now passed to a first punch which cornes down on the needles `1 as shown in Figure 4. The punch has a cavity 14, which passes over the bushes 9, and the tip of the punch bears on the runner causing the coned head of the insert 13 to penetrate a short distance into the runner. The primary purpose of this punch, however, is to force the upper end of the needle shaft down llush with the top of the bush 9.

' The next punch shown in Figure 5 comprises a central punch 15, the head of which is coned so as to drive the shaft of the needle yet further down through the bush 9. This punch is surrounded by a sleeve 16, which is urged by a spring downwards over the head of the punch 15. Except for an axial bore fitting roundthe head of the punch l5, the lower end of the sleeve 16 is closed. The axial bore is coned at this lower end so as to fit over the bush 9. The sleeve 16 is free to slide on the punch i5 but its movement is limited by the pin 17, carried by the punch 15 and projecting through a slot 18, in the sleeve. When this punch is bearing down onto the head of the bush 9, the coned part of the sleeve 16 tits over the bush 9 and squeezes it slightly into the needle and serves to locate the axial bore accurately relative to the bush 9. When the sleeve 16 can descend no further the punch 15 continues to descend and engages the head of the needle shaft 1 and forces it part of the way through the bush 9 as shown, at the same time forming a coned recess in the top of the bush. The pressure exerted in this operation causes the sharp lim of the insert 12 to penetrate still further through the runner 8.

After this operation the dienest with the needles and runner is removed from the press, and turned brass or stamped metal mounts 19, are fitted over the bushes 9. The assembly then passes to the G-hammer press shown in Figures 7 and 8. ln Figure 7 the mechanism of the press is shown diagrammatically and comprises a vertical bar 20, arranged to slide vertically in guides and carrying a punch 21 at its lower end. The punch 21 is locked into the lower end of the bar Ztl by a set screw 22. Above each bar a hammer 23 is mounted, pivoted to turn aboutl an axis 24, and actuated by a push rod 25, having a follower roller at its lower end 26, which rides on the surface of a triple throw cam 27 on shaft 28. To raise the punches clear of the work a rocker arm 29 is provided pivoted at 3d and having one end engaging in a notch 3l of the vertical bar 20. The other end of the rocker arm 29 is engaged by the upper end of the control rod 32, which is connected at its lower end by a link 33 to a pedal 34 pivoted at 35. Thus when the pedal is depressed as shown in Figure 7 the punch 21 is lowered and the follower 26 engages the surface of the cam 27. When the pedal 34 is 21 fand the hammer -23 is =lifted by the vertical bar A20 SQ tbatttie .follswsr 2 6 .is r.Carrisfl clear Of the .Cam 27 The action of the punch 21 is shown in Figure 8. it has a cylindrical part 37, whichenters the bore of the metal mountand the -conedtipof tlreipart-SY engages the bush 9 swaging it into tight and intimate `contact with themount 19, and the shaft of the needle 1. Three blows of the hammers 23are sufficient, that is to say one revolution of the shaft 28, 'and this `also causes the head of the vclieinsert 12 finally top'enetrate through the runner 8 as shown in FigureS. ThexpunchiZl is ncwraised again and the holder 38, having six spring clips 39 spaced at the same intervals as the mounts 19,`is vfitted on the mounts 19 which a'r'e thencremoved from 'the die-nest. The runner 8 is left behind and `can be returned for remelting.

The pointsofthe needles are new passed'over a boiling wheelto remove anyburrs and the needles are'now tested, after which they are passed "for inspection still set in the holder 38, and `mounted on the inspection jig shown in Figure 10 comprising six spigots 4d mounted on a bar 41. The spacing of the spigots is the same as ihespacing o f the clips 39, so that the needlesmay `be mounted directly on these spigots and the holder 38 removed. The spigots are arranged so that when theineedles are'mounted on them they are immediately beneath -a powerful magnifying glass through which `they are inspected. The needles can be freely rotated on the spigots 4t) for this purpose. After inspection the holder 38 is retitted and the needles removed and they `are then transferred to the apparatus shown in `Figures 11 -and 12 for arranging suitably for packing in at tin boxes. Figure 13 shows the arrangement of springclips 43 projecting upwards from a card of plastic material '42, through holes in which the spring clips project. Six needles aremounted at each side of the card 42`With their points projecting inwards, and, in

the example shown, for economy of space alternate needles at each nside are staggered as shown, so that the mounts do'notv foul each other. The spacing of the clips 43`in each set of six clips is thus staggered and closer together than the spacing of the spring clips 39 lon the holder 38. The apparatus shown in Figures 11 and 12 is designed to receive needles from the holder 38 and adjust their spacing automatically to correspond with the arrangementof the spring clips 43.

The apparatus consists of 6 metal bars 44 mounted between guides 45 and each provided at one end with a spigot 46 to fit a needle mount. The right hand bar as seen in Figure l1 is secured to the guides 45 and the bars are linked together by pivotedtoggle links 47 as shown. The left hand bar is provided with ahand knob 48 and its movement towards the left in Figure 1l vis limited by a stop bar 49. In the-'position of Figure y1l 'all the spigots 46 are in line and spaced' to correspond to the spacing of the clips 39 of the-holder 38, so that the needles held in the holder 38 can be fitted directly onto'the'spigots 46. When this has been done the holder SS-is removed and the 'knob 48 pushed towards thelrignt closing up the spacing of the bars 44, which are of Stich width that when they are together the'mounts are spaced a distance apart equal to the separation of the spring clips 43, while the toggle linkages 47 cause alternate mounts to be staggered as shown, so that the mounts are all ready to have the spring clips 43 applied to them. All six needles'are thus mounted on the card 42 at A'or'tceland are 'then removed from the loading jig. A further six needles are litted to the clips on the opposite side of the card 42, which is then packed in its box.

This method of adjusting the spacing of the needles by simultaneously moving the members carrying the spigots 46 can be achieved in various other Ways; for instance, by cams or other types of linkage such as a lazy tong. The mechanism chosen will depend of course, on the arrangement of the needles when they are packed, and may be used to increase thedistance` between the needles as well as to decrease it. This may be necessaryv inpacking needles in sterile foil orplasticspacks, when -the needles, in sets of, say, six, are spaced side by side without Staggering and .packed keach in an envelope of foil or thermoplastic material the envelopes being made in strips and later severed from eah other. spacing of the needles during manufacture as described may be one half inch, which may have to be increased to one and a quarter inches for packing in this way.

The method of manufacture according to the invention is applicable to any type of needle in which the needle shaft is held in the mount by a cast bush. Thus double ended needles for use for injection from ampoules may be made in this way, either with turned or stamped mounts of the type shown, or with a central ball for mounting, or with a central transverse plate or `cam for engaging the syringe outlet.

I claim:

1. A process of securing hypodermic needles into mounts by which they maybe `attached to a hypodermic syringe, by means of softmetal bushes `surrounding the shafts -of each needle, the Abushes being swaged into bores 'in said mounts comprising casting a plurality of said bushes around alike number of said needles simultaneously on one continuous-runner atpoints intermediate the ends'of said needles, sliding said needles axially in said bushes to position said bushes at the rear ends of said needles, yfitting a mount over each of said bushes, swaging said bushes intointimate contact with said needles andV said mounts, and separating said bushes from said runner.

2. A process accordingtoclaim 1, in which the bushes are separated from therunner during the swaging operation. v

3. A process according toclaim.2, in which each bush is separated from the runner by the `sharp edge of one of a set of `circular dies 4through which the shafts of the needles are passed, and on which the runner rests during the fitting of the-mounts :andswaging of the bushes.

4. A process according-to claim 1, in which, afterthe bushes have beencast, theshafts of the needles are pressed through the bushes so asto be flush with thc ends of the bushes, after which the Jneedles areprcssed through the bushes still furtherfand the mouth-of the lbores of the bushes opposite to'the points of the needle shafts are axially coned.

5. A process according to claim `4, in which the runner rests on the diesduring the pressingoperation and is partially cut'throughiby the dies during this operation.

6. A process aceordingto claim 2, in which after the bushes have been separated from the runner, needles are graspedfand held in a like number of similarly positioned spring clipsfrom `whichthey-are transferred to a like number of parallel spigots, after which thc positions of the spigots `are l simultaneously adjusted to move the needles into lthe correctpositionffor packing, the number of needles in a set correspondingto the number required for packing at' onetime.

7. 'A processaccordinglto claim 6,-in which the needles are eventually packe'd lside 'by 'side 4in rows, alternate needles beingstaggered, and the `spigots on which they are mounted prior t'o packing arerarranged on parallel members linked "by toggle linkages so that when thc Iinkages'are extended,fthe spigots are side-by-side in line withfa spacing equal to thespacing ofthe bushes on the runner, and when the members are close together thc toggle linkages 'move lthe spigots, and therefore the mounts, into a position in which the needles are spaced and staggered 'readyfor-packing.

References' Citedn the tile of this patent UNITED STATES PATENTS 1,782,447 Scrantom Nov. 1930 2,040,165 Baldwin e May 12, 1936 2,137,538 `McIntosh Nov. 22, 1938 2,177,191 Sandberg -..u Oct. 24, 1939 2,226,849 Douglas en A Dec. 31, 1940 For example, the

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