CA2318229A1 - Device of the manual syringe type for proportioning and dispensing fluid or pasty products - Google Patents

Abstract

A device of the manual syringe type (10) for proportioning and dispensing fluid or pasty products comprises a main body (12) provided with seizing means (20) and with guide means (19) between which a cartridge member (23), having a substantially uniform, preferably cylindrical section is inserted and guided along a straight path. The device also comprises an at least partially elastic piston (24), adapted to exert a sealing action against the inner walls of the cartridge (23). The main body (12) also comprises a plunger member (21) whereon a needle (11) is fitted. After a displacement of the main body (12) relative to the cartridge (23) the plunger member (21) causes the piston (24) to slide inside the cartridge (23) for drawing a fluid or pasty product therefrom and dispensing it through the needle (11).

Description

. WO 99/~blla PCT/EP991Up357 DEVICE OF THE MANUAL SYRINGE TYPE FOR PROPORTIONI~1G AND
DISPENSING FLUTD OR PASTY PRO~7,UCTS
nescr=ption The present invention relates to a 3evice pf the man:~al syringe type for proportioning anc~ dispensing fluid or pasty products.
The invention has the object to provide a device of the aforesaid type, involving a simple and economical production, and a simple and quick use. The invention. also has the ob~ecL
to provide a device consisting of a reduced number of components, made from a small quant~.ty of material, sc that the total cost of the device may be reduced.
Another obj ect of the invention ~.s to provide a device o~ the so-called ~~throwaway" type, in which the amount of material to be disposed is very l~.ttle, resulting in a reduced environmental impact. A non-minor object of the present ~nvent~.on ~.s to provide a device as descr~.bed here~nbefore, also comprising some reusable elements.
A further object of the invention is co provide a device wherein the fluid or pasty produce may be filled or refilled ~n a simple manner, and which is immediately ready-to-use with no need for transferring fluid from one container to the ocher or from one container to the device.
In ordEr to achieve the above objects, the invent~.on relates to a device as described hereinbefore, having the characteristics as defined in claim 1 below.
Further characteristics and advantages will be apparent from the following deta~.led description o~ a few embod~.ments of zhe invenci.on, referring to the accompanying figures, provided only by way of a non-restricting example, in which:
- figure I is a perspective exploded viev,r of a f~rsc embodiment of the invention, - figure 2 is a perspective view of a second embodiment of WO 99136114 PCT/!»P99iQ11.3S7 the invention, showing two possible variations, -- figure 3 is a top view of a further variant of the embodiment of figure 2, - figure 9 is a longitudinal sectional view of a third embodiment of the invenc~on, ,' - figure 5 is a longitudm~l sectional view of a fourth embodiment of the invention, - figure 6 is a longitudinal sectional view of a variant of a construction detail of the invention, - figure 7 is a side schematic view of a fifth embodiment, - figure 8 is a schematic view of a pair of fluid cAnxainers which may be possibly used in connection with the present invention, - figures 9 to 11 are side schematic views of variants of the embodiment as shown ~n figure 7, - figure 12 is a longitudinal sectional view of another variant of the embodiment as shown in figure 2, - figure 13 is a longitudinal sectional view of a sixth embodiment of the invention, - figure 14 is a side view of a variant of the embodiment as shown in figure 7, - figure 15 is a schematic view of a seventh embodiment, -figure 16 is a schematic view of an optional characteristic which may be adopted in the present invention, to allow a used needle to disappear inside the syringe body, - figure 17 is a schematic view of a further embodiment of the invention, - figure 16 shows an application example of the present invention, in~ the form of a toothpaste dispensi:~g device integrated i.n a toothbrush, and .
- figure 19 shows a variant of a body for supporting a needle and a cartridge according to the present invention_ With reference no~,r to figure 1, a proportioning and d~.spensing device of the manual syringe type, generally indicated with numeral lo, comprises a needle 11, which ~s mounted on a bearing structLre 12, preferably, but not limited Lo, made of plastic. The bearing structure comprisEs a front crossbax 17 from wh~.ch tuo stringers 18 extend to support a tubular lead-in guide 19, externally provided with two wings 20. A major portion of the needle I1 extends out of the bearin5 structure 1?. and ends at one end with a po~.nt 13a, normally protected by a needle-cover, which may be snap-clutch- or pressure-fitted on the beaxing structure 12.
Preferably, near the mouth of the needle-cover Ig a rather wide protection 15 is formed to protect the fingers of a ;user, during the needle covering operations.
The other end 13b of the needle, also ending with a point, projects out of a cylindrical sleeve 16 fastened on the bearing structure 12, at the m~.ddle of the cro$sbar 17.
The cylindrical sleeve 16 extends parallel to the stringers 18 and ends with a pressure disc 21; substantially concentric with the tubular lead-in guide 19. In a preferred embodiment of the invention, a mushroom head stake 32, whose function will appear more clearly hereafter, projects out of the pressure disc 21.
A cartridge, or carpule 33, containing the fluid to be injected or dispensed, has a substant~.ally cylindrical shape, plugged at the rear end 23a. The outside diameter of the cartridge 23 substantially corresponds to the inside diameter of the lead-in guide 19. A cylindrical piston 2g, preferably made of rubber, is slidably mounted at the front portion of the cartridge 23, so as to exert a sealing action thereon.
In using the device l0, the cartridge 23 is inserted in the lead'in guide 19 and pushed against the pressure disc 21, while holding the device to as is conventionally done with prior art syzinges, i.e. by grasping by the index and middle fingers the wings 20 of the bearing structure 12, and by pushing the bottom 23a of the ca=trzdge 23 by the thumb. The WO 99!36114 1'C'f/EP99/00357 .
pressure of the cartridge 23 on the pressure disc 21 causes the needle point 13b to penetrate the piston 24, thereby perforating it_ In subseguent operations, the fluid contained in the cartridge 23 is free to be discharged therefrom through the point 13a of the needle 11, v,rherefrom the needle , covering 14 has been previously removed_ 1~s is easily remarkable, the structure of the device 1D
~s much lighter than that of a traditional syringe and uses a smaller number of components. Further, the structure 10 does not include the plastic barrel of traditional syringes, thereby involving apparent material swings, since the cartridge itself holds the fluid and acts, at the same time, as a plunger. Therefore, the device 10 is clearly shown to have a lower cost, when compared with traditional syringes, and to imply a considerable reduction in the material to be disposed, also when it is used once_ The mushroom head stake 22, if there is any, is designed to be engaged in a corresponding cavity formed on the pistor~
24, elastically enveloping ~.t, so that the device to may be also used to suck in fluid through the needle 11, by pulling the cazLr~.dge 23 back. Here, in the rear part of the cartridge z3, a thicker collar may be formed. to assist the removal of the cartridge 23 from the bearing structure 12, and the consequent suction of fluid through the needle 11.
Figure 2 shows a second embodiment of the invention, intended to be used with a cartridge z3 similar in all respects to that described with reference to figuxe 1.
Particularly, a device l0a comprises a body 25, consisting in _ a tubular shell 25a, provided with a longitudinal aperture 26. At the rear end of the body 25, two Wings 20a are formed, whereas the front end is closed by a transverse wall 28, wherein a housing notch 27 is foamed. The longitudinal aperture 26 has two transverse widened parts 2fia, Z6b, near the wings z4a and the wall 28 respectively-WO 99J36I 14 PCT/EP99l00357 Different types of dispens~rg members may be provided 'n the i~ody 25, two of which are shown by way vz example in figure 2, znd.icated with numerals 29x, 29b respectively. A f~.rst type of dispensing member 39x, the simpler one, comprises a tubular element 30, wherein a neecle 11 zs fitted, and which is provided, at its rear end, with a pressure disc 21 and, possibly, with a mushroom head stake 22, identical in all respects to those described with reference to figure 1. Near the front end of the tubular element 30, two spaced abutments 31 are formed, the distance therebetween substant~allv corresponding to the thickness of the wall 28 of the body 25.
Thanks to this configuration, the dispensing member 29a may be inserted in the body 25 to cbtain a dispensing device which is functionally similar to that shown zn figure 1 and previously descr~.bed.
Another type of dispensing member, indicated with numeral 29b in figure 2, comprises an elongated element 32, wherezn a portion of the need7.e 11 is housed, and whezeon there is provided a sequence of lateral notches 33, separated by baffles 34, and designed to be selectively inserted in the housing notch 27 formed zn the front wall 2B of the body 25.
Naturally, the shape of the elongated element 32 is given purely by way of example and may obviously be modified, for example caking a configuration similar to that of the tubular body 30 of the dispensing member ?9a, whereon a plurality of abutments 31, haying the same functions as the baffles 34, may be formed_ The dispensing member 29b prov~.des the device lox with an additional characteristic, not mentioned herebefore, that is the possibility to predetermine the quantity of fluid Lo be dispensed by simply selecc~.ng the insert~.on position of the dispensing member 29b on the body 25, and particularly in the housing notch z~_ Hased on the position of the dispen9ing member 29b on the body 25, the rubber piston 2~3 of a WO 49/3bl la PCT/EP99/00357 -cartridge 23 inserted in the body 25 will be accordingly ' compressed in different pullout posit~.ons of the cartridge 23, thereby causing the quanta.ty of fluid discharged through the needle 11 to change, before the front edge 23b of the cartridge abuts against the wall 28 of the body 25.
Naturally, reference marks may be provided on the elongated element 32 and/or on the cartridge 23, for example silk screen printed indications, intending to offer the user an indication about the quantity of liguid available ~or dispensing, according to the position taken by the elongated element 32 on the body 25. The illustrated device, with reference to both dispensing members 29a and 29b exemplified in figure 2, allows to dispose the dispQnsing member only, whereas the body 25 may be reused an unlimited number of times. Hence, the material needing to be disposed is very little, with apparent advantages in terms both of inexpensiveneas and of environmental protection. It ~.s also important to remark that the dispensing member 29a, 29b may be removed without touching it, since, once the used up cartridge 23 is removed, the dispensing member can be simply extracted from the body 25, by gripping Lhe latter and beating the dispensing member or pushing it against a hard surface, for example against the edge of a rubbish bi.n, to disengage it from the housing notch 27. This reduces the risks for the user, particularly the risk that he may get pricked by the no longer sterile needle 11_ A varlanc of the dispensing member is illustrated in figure 12, wherein the same reference numerals indicate the same elements as sho~rrl ~.n figure 2 _ F;ere, the body 25 may house a dispensing member 29c, composed of a tubular-element 3oa, for example provided with abutments 31 or zidges like in figure 2, wherein a stem Sob, which bears the needle 11 and which is prov~.ded, at its rear end, with the pressure disc 21, may be moved axially. In the pre-utilization posit~.on, the WO 99(,~b114 PCT/~P991Q03S7 d~spensmg member 29c keeps the needle 11 protected, enclosing it in the tubular element 30a- When the cartridge 23 is inserted, a f~.rst length of its axial displacement causes, thanks to the thrust of the piston 2~#, xhe Stem Sob to be axially displaced and the needle 11 to come out. This axial displacement stops when'~the zest port~.on of the tubular element 3oa abuts against the pressure disc 21, on the side opposite to the piston 2g, which is then perforated by the rear point of the needle 11, Go allow the product contained in the cartridge 23 to be dispensed. The sequential abutments 31 allow to preset the guantity of dispensable fluid, in the same manner as dESCribed above w~.th refe=er~ce to the dispensing member 29b- At the end of the operation, the tubular element 3oa acting as a cap, may be irreversibly locked.
All the apparatus illustrated hereinbefore, using a dispensing member which can be separated from the body ~5, may be provided with a system to assist the removal of the member for separating it from the body after the dispensing operation. In its simplest form, said system comprises a flexible tongue formed on the body 25, on the side opposite to the longitudinal notch 26, whose compression helps the dispensing member, and thus the needle 11, to come out_ Figure 3 shows a variant 10b of the dispensing device described above. A tubular body 25b, provided with wings 2ob aG its rear, has an upper aperture 35 wherein a dispensing member 29d with an e~cternally threaded cylindrical body 36, through which the needle 11 is fitted, may be inserted_ The ~ronz wall 28a of the dispensing device lob has a housing notch 27a with a semicircular thread at its bOZLOm 27b. A
stop open ring 37, which may be rotated to close the upper part of the housing notch 27a when the dispens~.ng membex 29d is inserted in the notch 27a, thereby locking it, is rotatably mounted around the body 25b, aL the Wall 28a_ Wo99136iia PCT/Epg9~003~ -This configuration of the dispensing device lOb allows a fine adjustment of the quantity of dispensable fluid, by simply screwing the threaded body 36 in the housing notch 27a. Also, the operations to dispose the dispensing member 29d are as simple, qu~.ck and safe as those described with reference to _-the d~.spensing members 29a and 29b of figure 2 and 29c of figure 12. the stop open ,ring 37 need only be rotated to disengage the member 36 from the notch 27a. Also in this case, reference marks rnay be provided on the dispensing member 29d, on the body 2Sb and/or on the cartridge 23, zo indicate the dispensable quanti.Gies of fluid, cozresponding to a certain rotation of the threaded body 36.
The above e~camples of dispensing members 29a, 29b and 29d may be naturally provided with a needle-cover similar to that shove and described with reference to figure 1, or anyway of any other well-known type. On the other hand, figure 4 shows an automatic-release needle-covering system. A needle 11 is partially housed inside a tubular element 38 and fastened thereto near its rear end 13b. The tubular element 38, provided with the above-mentioned pressure disc 2~., is fastened at its front part to the front transverse wall 39 which closes a tubular lead-in body 25c. A small slidable tube 9o is slidably fitted on the needle and covers, ~.n the pulled out position, the port~.ort of the, needle 11 projecting out of the body 25c, including the front point 13a, whereas.
in a retracted position, iz is housed inside the tubular element 38. The front end of the tube g0 is fastened to a bracket 41, provided with a retaining ring 42, which e~sternally encircles the body 25c, and is allowed to axially slide thereon. An annular ridge 43, foamed on the outer shell -of the body 25c prevents the bracket 91, and thus the tube 40, from being slipped off. A manually controllable appendix 49 projects on the upper part of the bracket_ A longitudinal notch g5 is formed on the upper part of the . WO 99l3b114 PCTlEP99100357 body 25c, to allow the bracket 41. to slide, by controlling the appendix 44. In the needle-covering position, as shown in figure 4, the bracket gl is locked in pos.~cion by a lock.~ng tooth 46, placed at the front end of a flexible blade 47, which ~s coupled to the tubular element 38 near the pressure d~.sc 21 and prov~.ded, in this position, with a slanted tooth 48.
When a cartridge 23 is inserted ~n the body 25c, ~.ts front edge 23b interacts with the slanted tooth 48, thereby causing the flex~.b~e blade ~'7 to be bent down and, co~sequerlz~y, the locking tooth g8 to be disengaged from the bracket 41. Then, the bracket 41 can be pulled back, Dy controlling the appendix 44, and the front end 13a of the needle 11 can be uncovered only when the cartridge 23 is inserted and the dispensing device is ready for use. After use, when the cartridge 23 has been pulled off, the bracket 41 can be brought back to the lock position as shown in figure 4, by controlling the appendix 44, to cover the needle 11.
Naturally, the dispensing device lot as shown in figure 4 may be modified in such a way that the assembly of elements composed o~ the needle 11, of the tubular element 38, of the bracket ~#1 and of the tube 40, may be pulled off and removed from the body 25c, according to the principles described and illustrated above with reference to figure 2.
Figure 5 shows a further var~.anz of the invEntion, relating to a dispensing device lod, provided w~.th an automatic mechanism for covering the needle 11, at the end of the dispensing operation. Particularly, r.he device lOd comprises a tubular body 25d for leading in a cartridge (not shown), identical in all respects to the body 25 of figure 2 _ Under said body 25d, in a d~.ametrically opposite posit~.on with respect Lo the notch 26, a sleeve ~9 is fastened, inside which a piston 5o is sl~dably mounted, under the pressure of an elastic member 51, particularly a helical spring, 4 PCT/~P99/Dp357 -'10 .
compressed against a bottom 52 of the sleeve q9_ An upper -portion of the piston 5o is conformed like a flexible blade 53, with an end slanted tooth 54 projecting inside the body 25d near the bottom wall 56, through a cavity 5S adjacent thereco_ A fork-like supporx 57, whereon the front end of a needle-covering tube 58, provided with a pair of abutments 59a, 59b, is inserted, extends from the piston 5D. The needle-covering tube 58 is slidably fitted inside a tubular element 60, which is inserted, in the same manner as described above, in a housing notch 6~., formed in the front wall 56 of the body 25d. on the tubular element so, a longitudinal notch is made, which has, in its front part, a stop baffle or another element designed to retain and lock a safety tooth 64, placed ac the end of a flexible blade 65 formed on the tube 5Q.
In using the dispensing device lOd, when a cartridge -inserted in the body 25d - reaches its front wall 56, is causes the slanted tooth 54 to come out of the aperture 55 and consequently determines the release of Ghe piston 50 which, under the action of the spring 51, drags the tube 58 forwards, until the latter totally covers the needle 11. The safety tooth 64, by interfering with the baffle 63, prevents any subseguent attempt co uncover the needle 11, which may be removed safely, together With the tubular element 6o, from the body z5d, through the housing natch~6l.
In the examples described and illustrated hereinabove, the rear point 13b of the needle 21 projects out of the central support tubular element. An alternative thereto, which allows Lo protect the rear point 13b of the needle 11, reducing the risks that a user may get pricked therewith, is shown in figure 6. A general tubular central support 66 houses a needle 11, whose rear point 13b, designed to perforate a general rubber piston 67, is protected by a cap 68, provided with internal hook-like teeth 69, designed zo retain a WO 99I3b114 HCT/$P99/00357 deformable annular crown 7D formed on the rubber piston 67.
Figure 19 shows a variant of the body which bears the needles and guides the cartridge 23, as described above.
Particularly, the body 125 is divided into two portions 125a, 125b, mutually articulated about a transverse axis 126 placed near the area in which the cartridge 23 is introduced. TWo gripping zings 127, lZ8 are fastened to the two portions 125a, 125b, which extend behind the transverse axis 126 in two respecz~.ve tails 129a, 129b- A safety appendix 130, controlled by a slider 131, is preferably mounted on the body 125, aiming at selectively uncover one of the needles described and illustrated above, for example that shown in f figure S , which may be inserted in the notch 2 7 . Naturally, the safety appendix 134 is wholly optional and, if there is one, it may be of the manual or automatic type, as previously described.
In using the body 125, a needle may be easily grasped by acting on the gripping rings 127, 12~ to open the portions 125a, 125b apart 7.n the area of the notch 27. When the portzons 125a, 125 are closed again, once the needle has been placed in the notch 27, the tails 129a, 129b are brought back to the configuration as shown in figure 19, thereby defining a substantially circular aperture, allowl.ng the cartridge 23 to be inserted therein. Once the cartridge 23 has been inserted, the poxtions 125a, 125b are prevented from opening apart by the interfezence of the tails 129a, 129b with the outer wall of the cartridge 23.
A further va=iarit toe of the invention is shown in figure 7 and comprises an elongated central body 71, which may have a circular or, more preferably, cross-shaped section, wherein a needle lla is housed and whereto a deformable piston 72, preferably made of rubber is attached, at the rear part thereof. Here, it ~s not necessary to provide the needle lla with a rear point. A finger-bearing structure 73 completes WO ~9r3b114 , ' ' ~ ~ PCT/EP99/00357 the device loe. A cartridge 74, of the simple, cylindrical , -glass-type is inserted on the device loe, and has the function of a plunger. The cartridge 74 may consist, as shown in figure s, of a vial 75a, 75b, for example having a stress raising nick, outlined by the dashed line 76a, 76b, annularly encircling the cylindrical potion under the neck 77a. 77b.
Figure 9 shows a variant of the.deviee of figure 7, wherein, besides the piston 72, a further disc 78, for centering the cartridge 7~ is placed on the central elongated body 71.
Figure to shops a variant of the dispensing device, wherein instead of a needle, a dispenser 7s is provided, possibly, but not necessarily articulated in so, for example for dispensing foodstuff, creams, toothpaste and similar.
Advantageously, the articulation 8o may be made in the form of a stop valve, preventing the product to c4me out when it is partially used and when a further uae thereof is foressen-Such a stop valve may be made in any other manner, which will be apparent, to those skilled in the axt, from the present description and from the drawings annexed thereco_ As an alternative, or as a spare accessory, she dispensing device may be provided With a dispensing spatula 81, as shown in figure 11. A specific application example in the form of a brush x.09 is also illustrated in figure 18, which shows a dispena~.ng device whose elongated central body 71a, provided at one end with the piston 72 , extends . on the opposite side by an appendix 71b, to whose end b~'istles 110 are fixed. 'The central body 71a is wholly or partly enveloped by a covering structure 111, having the function of a handgrip for the brush- The cartridge 74 containing the product to be dispensed is slidably fitted on the piston 72 and communicates with art axial duct 112 Formed in the central body 71a and in the appendix 71b, which opens out at the base of the bristles 110_ 8y pressing the bottom 113 of the cartridge 74 , the product contained there~.n may be forced Lo WO 99136114 PCT/1'P99/Op357 allow the desired quantity thereof to come out at the bristles 110. As a variant, if the internal cavity llla of the covering structure 111 has a substantially cylindr~.cal shape, a thread may be Formed thereon, to be engaged on a corresponding thread formed on the outer shell of the cartridge 7g- so. the product may be supplied to the bristles 11o by screwing the cartridge ~4 in the cavity llla, for a desired number of turns; the latter variant ~.s particularly advantageous to - prevent the product to come out unintentionally in case of accidental shocks. Naturally, the special c embodiment ~llust~:ated above may be particularly but not exclusively used ~n the field of toothbrushes, particularly travel toothbrushes, as well as in the field of brushes for shoes or clothes, for cars, for personal hygiene, only to mention a few application examples.
The cartridges 7~, bes~.des being obtained by breaking the vials 75a, 75b, may be also provided as cylindrical containers, covered by a plug, or by a film, possibly - but not exclusively - provided with a tear-off opening.
Particular advantages may be obtained by providing that the cartridges 74, having simple and smooth shapes, may be easily made from materials other than glass, such as paper, or similar, especially, in cases of use with foodstuff.
Figure 13 shows a dispensing dev~.ce in which the only discarded part, at the end of the dispensing operation, is the needle 11 _ This device comprises a lead-in body 82 , for receiving a cartridge as shown in figure 1, whereto a perforated central stem 83 terminating by a pressure disc 21 and being able to rece~.ve a needle 11, is integrally fastened. The central stem 83 has, in a front area, a longitudinal hollow ag, wh~.ch may be penetrated by a portion of a cam 85, articulated to the body 82. In the pos~.tion shown in the figure, the cam 85 locks the needle 11 in order to allow a product contained in a cartridge (not shown? to be WO 99136114 PC'1'/FP99~0~357 dispensed- A the end of the d~.spensing operations, a rotat~.on of the cam 85 in the direction of arrow A allows the needle 11 to be pulled off (possibly by gravityf and consequently removed- Naturally, instead of the cam 85 any other retaining device may be provided, for example button-, spring-, and .
piston- or otherwise operated'.
Figure lg shoc,rs a variant of the solution illustrated in more general terms in figure 7 above. Here, the bearing structure 73 for the fingers of the operator comprises a pair of opposed foils 86, which are plastically hinged in the areas 88, and terminate in two wings 20, provided w~.th hook-like teeth 87a, 87b respectively. When all the product contained in the cartridge or vial 74 has been di$pen~ted, the foils 86 are rotated 180° towards the needle lla, in the d.ireczion of arrows ~, until the two hook-like teeth 87a, 87b mutually engage, in such a way that the foils and the wings 20 form a protection for the needle lla, preventing accidental pricks-Since the diameter of the mouth 7~a of the cartridge 74 is greater than the distance between the two foils 86 in the area of the plastic hinge 88, when the cartridge 74 reaches the end-of-stroke at the end of the dispensing operation, the rotation of the two foils 86 in the direction of arrows 8 is facilitated.
Figure 15 schematically sho~rs a further embodiment of the present invention, particularly - but not exclusively -intended for packaging sterile syringes in blisters or similar, wherein, for the sake of illustration simplicity, the needle-cover has been omitted. In th~.s solution, a needle lla, or more generally a discharge duct, is fastened to an internally perforated pusher body 90, provided with a finger- -bearing structure 89. The needle lla and the internal hole 91 are at a radial distance from zhe axis of symmetry of the pusher body 90, which is supplied, at its rear part gob, with a sealing member 92, particularly, but not exclusively, a ' WO 9913611a PC'fIBP99i00357 r~.ng, for example an O~ring. The rear part gob a:zd the sealing member 9~ are inserted, during the manufacturing process, in a flexible piston 93 movab?e in a cartridge 94 conta~ring a product to be dispersed or injected. In detail, the piston 93 has a cavity 95, cozresponding as a negative to the rear part gob of the body 90. A hole 96 allowing communication with the ins~.de of the cant=~.dge 9., is formed on the bottom of the cavity 95 in a c'~amatzicaliy opposite pos~t~.on with respect to the through ncle 91.
Before use, the dispensing device, or syr~.nge of figure 15 is assembled is such a way chat the Fro3uct conta~.ned in the ca~-tr~dge 9~ is not allowed tc come oL= of tre needle lla, because the hole 9~# , formed in the p_ston 93 , i s plugged ac the bottom gob of the body 90. In order t~ use the product and dispense or ~n3ect it through the needle 11a, the body 90 reed only be rotated about a longitudinal axis, for example over 18o°, until the holes 96 and 91 are coaxial.
Figure 17 schematically shows an alternative example of a needle or discharge duct llb, fitted dur=:gig the manufacturing process on a piston 97, which may slide within a cartr_dge 98. Particularly, the needle llb is inserted in a rotat~.ng member 99, which is housed inside the piston 97, having a hole loo which, when the needle llb ~.s ~n the position as shown in a continuous line in figure 17, is plugged by the rotating member 99 _ on the contrary, when the needle llb is brought to the operat~.ng position, as shown is a dashed line Tn the figure, aligned wixh the sliding direction of the piston 97 in the cartridge 98., the ~rociuct contained therein is free to flow down zhxough the hole lop, the rotating member 99 and the needle llb after pressure is exerted at the bottom 98b of the cartridge.
Figure 16 shows a possible assembled configuration of a needle lla in a tubular body 101 compr~.sing an internal axial cavity 102, which capers in the end portion closest to the WO 99~b11i PCT/EP99iflfl~s"7 16 - _ needle 11a- The needle lla, in turn, hay at its base a .
conical thicker part 103, which is forced in the taper of the axial cavity l02 and keeps i.ts position during the use of the needle thanks to the friction forces mutually exerted by.the Walls. Once the needle lla has been used, a force greater than the friction between the cones is simply exerted on the needle point co have the needle lla retracted in the cavity 102, pzotecting the operator from accidental pricks.
Particularly, the retraction of the needle 11a may be obtained by beating, for example, the needle point on a hard surface, such as a table, a shelf, etc. The solution described herein may be used advantageously in most of zhe dispensing apparatus illustrated and described hereinbefore, as embodiments of the present l.nvention_ Then, the dispensing device In accordance with the present invention may be used both in the med~.cal field, for injecting pharmaceutical substances and in all fields where the dispensing of creams, pastes, oils or other fluid or pasty products is necessary or useful.
Naturally, notwithstanding the principle of the invention, the embodimer~ts-and the implementation details may be greatly varied with respect to the above description and illustrations, without departure from the scope of the present invention.

Claims (13)

1. Manual syringe (10a) for aspirating or dispensing fluid or pasty products, comprising a main body (25) defining a longitudinal axis and provided with guide means (26), a cartridge body (23, 74) containing said products, adapted to be inserted in said main body at a first end portion thereof and to be guided in said guide means (26) along an axial direction, with an at least partially elastic piston (24, 72) slidably mounted in said cartridge body (23, 74) and adapted to exert a sealing action on the inner walls thereof, a longitudinal dispensing element (29a, 29b, 29d, 30, 60, 66, 71, 83) provided internally with a through duct, with a nozzle at a first extremity and with a plunger member (22) at the second extremity thereof, said nozzle and said plunger member (22) reciprocally communicating through said duct, said plunger member (22) being adapted to move with respect to said piston (24, 72) in an axial direction from a piston closing position, in which the passage of said products from the cartridge body (23, 74) to the nozzle is prevented, to a piston opening position, in which the passage of said products is allowed, said plunger member and said piston element being adapted to selectively slide inside the cartridge body (23, 74) when a relative axial displacement between said main body (25) and said cartridge body (23, 74) occurs, characterised in that said main body (25) is provided with longitudinal (26) and radial (27) apertures respectively on its side wall and its end wall (28) opposite to said first end thereof, to allow selective insertion in and extraction from said main body of said dispensing element (29a, 29b, 29d, 30, 60, 66, 71, 83), the latter being provided with at least one peripheral recess (31, 33, 34), substantially transversal to said longitudinal axis and operatively co-operating with a protrusion of complementary shape placed in correspondence with said radial aperture (27), to establish a reversible mechanical bond between said main body (25) and said dispensing element (29a, 29b, 29d, 30, 60, 66, 71, 83) during syringe operation.

2. Manual syringe according to claim 1, characterised in that said protrusion is formed by the same end wall (28) of the main body (25) and said at least one peripheral recess is a groove (31, 33, 34), whose width is substantially equal to the thickness of said end wall (28).

3. Manual syringe according to claim 2, characterised in that said groove (31, 33, 34) is placed at said first extremity of said longitudinal dispensing element (29a, 29b, 29d, 30, 60, 66, 71, 83), on an enlarged portion thereof.

4. Manual syringe according to claim 3, characterised in that said longitudinal dispensing element (29a, 29b, 29d, 30, 60, 66, 71, 83) has a needle solidarity fixed internally in the axial direction thereof.

5. Manual syringe according to claim 4, characterised in that said needle extends outwardly from said second extremity of said longitudinal dispensing element (29a, 29b, 29d, 60, 66, 71, 83) to be adapted to penetrate said piston (24, 72).

6. Manual syringe according to claim 4, characterised in that there is provided a plurality of peripheral recesses (31, 33, 34) axially spaced for selective adjustment of the position of said longitudinal dispensing element (29b, 30a) with respect to the main body, to allow discrete adjustment of the quantity of said products to be drawn from or aspirated in said cartridge body (23, 74) with a complete piston stroke.

7. Manual syringe according to claim 4, characterised in that said at least one peripheral recess is formed as a thread (36) extending along a predefinite portion (29d) of said longitudinal dispensing element, adapted to operatively co-operate with a correspondent threaded portion (27a) on said end wall (28a) to allow continuous adjustment of the quantity of said products to be drawn from said cartridge body (23) with a complete piston stroke.

8. Manual syringe according to claim 4, characterised in that said longitudinal dispensing element comprises a first portion (30a) and a second portion (30b) to which needle (11) is solidarity fixed, the second-section being adapted to slide inside the first portion in the axial direction, between a first position in which the needle (11) is housed inside the first portion (30a) and a second position in which said needle (11) is partially extracted.

9. Manual syringe according to claim 8, characterised in that means (85) are provided for selectively remove said needle (11) from said longitudinal dispensing element (83).

10. Manual syringe according to claim 9, characterised in that there is provided a needle covering element (40, 65) slidably fixed on said main body (25) with selectively releasable locking means to selectively cover or expose said needle (11).

11. Manual syringe according to claim 4, characterised in that said main body (25) is provided with seizing means (20, 20a, 20b) for manual operation which are provided with articulation means (88) adapted to refold said seizing means (20) to a position towards the tip of the needle for covering it.

12. Manual syringe according to claim 4, characterised in that said piston (24, 72, 93) being provided with locking means (70) adapted to operatively lock said plunger member (22) for reversibly operate said piston in two opposite axial directions inside said cartridge.

13. Manual syringe according to any of the preceding claims, characterised in that said plunger member (22) comprises a pressure plate (21) designed to push said piston (24, 72, 93) to cause it to slide inside the cartridge body (23, 74, 94).