US1044688A - Syringe. - Google Patents

Description

J. PAYNE.

SYRINGB.

APPLICATION FILED 0GT.14, 1910. J*044,688*D Patented Nov. 19, 1912.

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Specication of Letters Patent.

Patented N ov. 19,1912.

Application filed October 14, 1910. Serial No. 587,046.

To all whom t may. concern Be it known that l, JOSEPH PAYNE, of Belmont, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Syringes, of which the following is a specification. 4

This invention relates chiefly to hypodermic syringes used by dentists and other practitioners.

The syringeincludes a barrel, to the outlet of which a hypodermicvneedle 1s connected, and a piston movable in the barrel and adapted to eject fluid through the needle.

The invention has for its object, first, to provide improved means for packing the piston and preventing leakage of the fluid between it and the rear end of the barrel.

The invention consists in the improvements which I will now proceed to describe and claim.

Of the accompanying drawings-Figure 1 represents a side view of a syringe to which my improved packing is applicable. Fig. 2 represents a section on line 2-2 of F1g. 1. Fig. 3 represents a section on line 3 3 of Fig. 1. Figs. 4 and 5 represent, respectively, a side and end view of the piston 'packlng embodying my invention, removed from the barrel. Fig. 6 represents' a section on line 6 6 of Fig. 5.

In the drawings, 12 represents a syringe barrel of cylindrical form, having an outlet at its forward end, and means such as a screw-threaded nipple 13 through which the outlet extends, for the engagement with the barrel of the base 14 of a hypodermic needle 15, said base being externally formed as a nut so that the needle can be screwed on or off. 16 represents an external screw thread formed on the periphery of the barrel near its rear end. The periphery of the barrel is reduced between the screw thread 16 and the rear end or extremity of the barrel, to form a smooth surfaced cylindrical portion 17 of smaller diameter than the screw thread, said portion constituting a guide for the packing case hereinafter described.

18 represents a piston which is movable ,in the barrel and is adapted to eject fluid from the barrel through the outlet, said piston, as here shown, being provided with a head 19 formed to bear upon the palm of the operators hand and hereinafter referred to as a palm-rest.

20 represents a hollow cylindrical packing case which is composed of a cylindrical shell of thin sheet metal formed internally to have a sliding t on the guide 17, and provided at its rear end with an inwardly projecting flange 21 which partially obstructs said end and forms an opening for the piston 18. The opposite end of the case is open or unobstructed.

22 represents a cylindrical packing sleeve of compressible material such as leather, rubber or any suitable packing composition adapted to be inserted in the unobstructed end of the case and to form a tight joint around the piston 18, said sleeve forming an opening which is a continuation of the opening formed by the flange 21. Said sleeve is formed to enter and closely fit the interior of the case 20 and to closely fit the periphery of the piston 18, the packing sleeve being shorter than the case and bearing at one end against the flange 21, so that the opposite end of the case, projects forwardly from the sleeve sufliciently to engage and slide on the guide 17.

23 represents a packing nut which has at one of its end portions an internal screw thread formed to engage the external thread 16 on the barrel 12, the oppo-site end of the nut being provided with an inwardly projecting flange 24 which bears on the rear end of the packing case 20. The portion of the nut between the flange 24 and the internal screw thread of the nut is formed to inclose the packing case 20.

When the packing is first applied to the syringe, the length of the packing sleeve 22 is such that when it bears on the rear end of the barrel, as shown by Fig. 2, the portion of the sleeve that projects over the guide 17 is separated from the shoulder 25 at the outer end of said guide, by a space of considerable width, so that there is room fora considerable forward movement of the packing case 20'. on the guide, and a corresponding compression of the packing sleeve 22. It will bel seen therefore, that the packing may be adjusted from time to time to compensate for Wear, by turning the nut 23 forward, and thus causing the packing case to slide forward and compress the packing sleeve, thus increasing its pressure on .the piston. The packing -sleeve 22 is separated from the nut 23 by the packing case so that there is no frictional contact between the nut and packing sleeve, the sleeve being therefore adapted to be readily compressed on the piston. The packing, composed of the sheet metal case 2O and the compressible packingv sleeve 22, may be put upon the market as an article of manufacture, a number of said packings being supplied with each syringe, so that the user may readily renew the packing by'discarding one of which the packing sleeve has been rendered useless and substituting another packing in its place without the necessity of touching the packing sleeve itself. y

26 represents a rest for two lingers of the hand which manipulates the syringe, said rest being arranged to aord a bearing for the lingers while the palm-rest bears against the palm of the same hand. rifhe finger rest is composed of a strip or plate having an enlarged central po-rtion containing an orifice 27 adapted to receive the barrel 12, and curved end portions or wings constituting the finger bearings and projecting from the opposite sides of the barrel. rllhe finger rest is removable from the barrel, and when in place on the barrel bears against the abutment 28 located between the ends of the barrel and rigidly secured thereto, said abutment being preferablyn ring or collar attached to the barrel in any suitable way, or if desired, formed integral therewith. The finger rest 26 bears on the side -of the abutment nearest the needle 15, so that pressure of the operators fingers on the rest tends to force it against the abutment. Rotation of the finger rest on the barrel is prevented by ears 29 formed on the barrel and recesses 30 formed in the finger rest to receive said ears, as shown by Fig. 3, the said ears and recesses constituting complemental members vfor interlocking the linger rest with the barrel.

31 represents a set screw engaged with a tapped socket in the finger rest and adapted to bear on the barrel to vprevent separation of the nger rest from the abutment 28. When the finger rest is removed from the barrel, it may be utilized as a wrench for applying and removing the needle 15, the finger rest being provided with wrench sockets 32 at its ends, each of which is formed to engage the nut 14 constituting the base of the needle. It is obvious that one wrench socket, instead of two, may be provided if desired.

l claim The combination with an externally threaded tubular member having a smoothsurfaced cylindrical portion of lesser diame- /ter beyond the threaded portion, of an internally threaded nut, a packing comprising a hollow cylindrical case adapted to be inserted in said nut and having at one end an inwardly projecting annular ange partially obstructing said end and forming an opening adapted to receive a rod, the opposite end of the case being unobstructed, and a compressible cylindrical packing sleeve fitting the interior of the case and forming a continuation of the opening in the annular flange, said sleeve bearing at one end against the iiange and being shorter than the case so that its opposite end is within the open end of the case, whereby the packing as a whole may be handled without contact of the fingers with the packing sleeve, the open end portion of the case projecting outwardly from the packing and forming a recess to receive the smooth surfaced portion of said tubular member. v

In testimony whereof l have aiiiXed my signature, in presence of two witnesses.

JOSEPH PAYNE. Witnesses:

C. F. BROWN, R W. lnzzn'r'rr.

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