Patent Description:
A cannula remover that comprises a separation mechanism for separating a cannula from a syringe is known from <CIT>. In order to perform a separation of the cannula from the syringe, the cannula firmly threaded on the syringe is introduced into a receiving part of the cannula remover and an activation of the separation mechanism takes place by a manual rotation of the receiving part. The authorities have stated that there is a risk that the user can puncture himself with the cannula when the cannula remover is being used to remove the cannula from the syringe.

A primary goal of the present invention is to indicate a safety arrangement integrated with the syringe that reduces the risk of an operator puncturing himself.

Another goal of the present invention is that the safety arrangement is user-friendly.

Another goal of the present invention is that the safety arrangement is economical.

Another goal of the present invention is that the arrangement is preferably a single-use type, as a result of which the hygiene is extremely high.

At least the primary goal of the present invention is realized by a method and a device that achieve the characteristics indicated in the following independent claims. The invention is as defined in independent claims <NUM> and <NUM>.

A preferred embodiment of the invention is described below with reference made to the attached drawings, in which:.

As is apparent from <FIG> and <FIG>, the device comprises, according to the present invention, a tube <NUM> and an annular casing <NUM> that can be mounted on one end of the tube <NUM>. The tube <NUM> has a length that is a multiple of the length of the casing <NUM>. In the preferred embodiment shown the tube <NUM> has a length that is approximately four times the length of the casing <NUM>. When the casing <NUM> is mounted on the tube <NUM>, the tube <NUM> and the casing <NUM> can rotate relative to one another around a common longitudinally running central axis.

In the embodiment shown the tube <NUM> has a circular cross section and its inside diameter is adapted to the outside diameter of the syringe S that the tube <NUM> is to be mounted on. In the embodiment shown the casing <NUM> also generally has a circular cross section and an inside diameter that is adapted to the outside diameter of the tube <NUM> in the area of the end of the tube <NUM> that the casing is to be mounted on. More precisely, the diameters are adapted in such a manner to one another that there is a sliding fit between the inside diameter of the casing <NUM> and the outside diameter of the end of the tube <NUM> that the casing <NUM> is to be mounted on. <FIG> and <FIG> show perspective views of the tube <NUM> and the casing <NUM>. Both the tube <NUM> and the casing <NUM> consist of two halves that are mirror images of each other, that is, an imaginary, longitudinally running plane of symmetry divides the tube <NUM> and the casing <NUM>. As can be seen most clearly from <FIG>, the tube <NUM> is provided with two diametrically disposed groups of parallel slots 11A, <NUM><NUM> B, 16A, 16B in the area of one end of the tube <NUM>. The slots <NUM>1A, <NUM><NUM> B, 16A, 16B extend in the longitudinal direction of the tube <NUM> and have a length constituting only a lesser part of the length of the tube <NUM>. In the embodiment shown the distance between the slots <NUM> A, <NUM><NUM> B respectively 16A, 16B forming a group is less than the length of the slots 11A, <NUM> B, 16A, 16B. A flexible strip -like part <NUM> of tube <NUM> is defined between adjacent slots <NUM> A, <NUM> B respectively 16A, 6B, wherein this part has an extension in the longitudinal direction of the tube <NUM> that mainly coincides with the length of the slots <NUM><NUM> A, <NUM> B, 16A, 16B. An external first ridge <NUM> is disposed following the one slot 11A, 16A in each group, which ridge has a length according to the embodiment shown, that is less than the length of the associated slot <NUM> A, 16A.

The tube <NUM> also comprises two external, diametrically placed heels <NUM> that have a certain extension in the circumferential direction of the tube. The extension of the heels <NUM> in the circumferential direction constitutes only a lesser part of the entire circumference of the tube <NUM>.

<FIG> shows an internal part, that is, one half of tube <NUM>, wherein the not-shown, internal part of the tube <NUM> has a corresponding shape, that is, the tube <NUM> consists of two halves that are the mirror image of one another. <FIG> shows the two slots 16A, 16B. <FIG> also show an internal heel <NUM> that is located on the flexible part <NUM>, wherein the heel <NUM> extends mainly between the slots 16A, 16B in the circumferential direction of the tube <NUM>. According to the embodiment shown the internal heel <NUM> is located approximately in the middle of the height of the flexible part <NUM>.

<FIG> and <FIG> show perspective views of internal parts of the casing <NUM>, wherein the casing <NUM> therefore consists of two halves that are mirror images of one another. As is apparent from <FIG>, the casing <NUM> comprises on its one end a col- lar <NUM> that forms a stop shoulder when the casing <NUM> is mounted on the one end of the tube <NUM>.

According to the embodiment shown, the casing <NUM> is provided with two internal recesses <NUM> that are generally square and located diametrically in front of one another. The internal recesses <NUM> extend in the longitudinal/vertical direction of the casing <NUM> corresponding approximately to half the height of the casing <NUM>. As concerns the extent of the internal recesses <NUM> in the circumferential direction of the casing <NUM>, it constitutes only a lesser part of the internal circumference of the casing <NUM> and corresponds in the embodiment shown mainly to the distance in the circumferential direction of the tube <NUM> between adjacent slots <NUM> A and <NUM> B, respectively 16A, 16B. Each of the internal recesses <NUM> is limited on the one side by another ridge <NUM> that was formed in that the wall thickness of the casing <NUM> becomes narrower in the direction of the recesses <NUM> in the circumferential direction of the casing <NUM>. The other ridges <NUM> extend in the longitudinal direction/vertical direction of the casing <NUM> and according to the embodiment shown the other ridges <NUM> have an extent in the longitudinal direction/vertical direction of the casing <NUM> that constitutes the greater part of the height of the recesses <NUM>.

The casing <NUM> is provided with two internal first tracks <NUM> that extend in the longitudinal direction/vertical direction of the casing <NUM>. According to the embodiment shown the length of the tracks <NUM> is somewhat shorter than the height of the associated recess <NUM>.

As is most clearly apparent from <FIG>, the casing <NUM> comprises internal parts <NUM> with a varying wall thickness in the circumferential direction. These parts <NUM> are disposed following the recesses <NUM> and in the same part of the height of the casing <NUM>. The parts <NUM> have the least wall thickness following the recesses <NUM> and, as was indicated above, this forms the other ridges <NUM>. These parts <NUM> have an increasing wall thickness in the direction away from the other ridges <NUM> and end approximately halfway between another ridge <NUM> and an internal first track <NUM>. The casing <NUM> is provided with two internal other tracks <NUM> that extend in the circumferential direction of the casing <NUM> and are located approximately at the half height of the casing <NUM>. The length of the other tracks <NUM> is shorter than the circumferential distance between adjacent edges of the two diametrical recesses and according to the embodiment shown the length of the second track is approximately <NUM>/<NUM> of the circumference distance between adjacent edges of the diametrically located recesses <NUM>.

<FIG> show different views, sections and details of how the casing <NUM> is mounted on the tube <NUM> in a starting position. As is most clearly apparent from <FIG>, the casing <NUM> is mounted on the tube <NUM> in such a manner that both recesses <NUM> in the casing <NUM> are located right in front of the flexible parts <NUM> of the tube <NUM>. In order to facilitate the correct mounting of the casing <NUM> on the tube <NUM>, the casing <NUM> is provided with tongues <NUM> right in front of the recesses <NUM>. When the casing <NUM> is pushed entirely on the tube <NUM>, the external heels <NUM> on the tube <NUM> engage with the other tracks <NUM> on the casing <NUM>. This is shown most clearly in <FIG>.

When the tube <NUM> and the casing <NUM> are in the assembled position shown in <FIG>, the tube <NUM> and the casing <NUM> are pushed onto an injection body SK in a syringe S. This is shown in <FIG>.

Before the tube <NUM> and the casing <NUM> are placed on the injection body SK, an ampule is mounted in a space in the injection body SK. This is not shown in <FIG>. As is apparent from <FIG>, the casing <NUM> is preferably brought in contact with a flange FL on the syringe S.

When the tube <NUM> and the casing <NUM> have been pushed onto the injection body SK, a cannula KA is mounted on the injection body SK, see <FIG>. When the tube <NUM> and the casing <NUM> are located in the position shown in <FIG> and a cannula KA is mounted on the injection body SK, an injection with the syringe S can take place, wherein a normal anesthetic is injected in the oral cavity of a patient who is at the dentist's.

When the injection has been completed, the tube <NUM> and the casing <NUM> are pushed into the position shown in <FIG> where the internal heels <NUM> on the tube <NUM> are taken up in third track SP going around the front end of the injection body SK, that is, the end at which the cannula KA is mounted. During the dis- placement of the tube <NUM> and the casing <NUM> from the position shown in <FIG> to the position shown in <FIG>, the user notices when the correct position according to <FIG> has been reached when the heels <NUM> click into the third track SP. In order to further anchor the tube <NUM> and the casing <NUM> on the injection body SK a mutual rotation of the tube <NUM> and the casing <NUM> takes place. A comparative study of <FIG> and <FIG> shows that the tube <NUM> has rotated <NUM>° relative to the casing <NUM>, wherein the rotation of the tube <NUM> took place counterclockwise while the casing <NUM> did not rotate, during which the external ridge <NUM> on the tube <NUM> clicked into the internal first track <NUM> on the casing. As an alternative to rotating the tube <NUM>, the casing <NUM> can be rotated while the tube <NUM> is not rotated.

During the above-described mutual rotation between the tube <NUM> and the casing <NUM>, in the position according to <FIG> thicker wall parts of the casing <NUM> come to be located directly in front of the flexible parts <NUM> in the tube <NUM>. These thicker wall parts come to exert a clamping action on the flexible parts <NUM>, so that the latter press against the injection body SK. Since the internal heels <NUM> are located on the inside of the flexible parts <NUM>, this clamping action presses the heels <NUM> into the third track SP in the injection body SK. As a consequence, a very good fixing of the tube <NUM> relative to the injection body SK takes place.

Syringe S with the tube <NUM> and the casing <NUM> is now ready to be used in a cannula remover, which will be schematically described below.

<FIG> show a holding component HO in the form of a casing that forms a part of a cannula remover that is described in SE <NUM><NUM> C2. Refer to the indicated document for more information about how the removal of the cannula KA from the injection body SK takes place. As concerns the method and the device according to the present invention, only the holding component HO is of interest.

As is most clearly apparent from <FIG>, the syringe with the tube <NUM> and the casing <NUM> is moved down into the holding component HO, wherein the end of the casing <NUM> that is pushed onto the tube <NUM> comes to rest against an internal first stop surface AY1 on the holding component HO. According to the embodiment shown, the internal first stop surface AY1 extends around the entire internal, cylindrical space of the holding component HO, that is, the internal stop surface AY1 is generally located in a plane that extends at a right angle to the longitudinal direction of the holding component HO. <FIG> show the contact of the casing <NUM> against the holding component HO. <FIG> also shows that a certain mutual displacement took place between the tube <NUM> and the casing <NUM>, that is, the tube <NUM> shifted downwards by a stretch that corresponds approximately to one half the height of the casing <NUM>. This mutual displacement between the tube <NUM> and the casing <NUM> is initiated in that the syringe S was shifted downward by a certain stretch by the operator, during which the engagement of the internal heels <NUM> with the track SP on the injection body SK entrains the tube <NUM> when the syringe S is shifted downward. Since the ridges <NUM> on the tube <NUM> are taken up into the first tracks <NUM> in the casing <NUM>, the ridges <NUM> slide in the first tracks <NUM> during the displacement of the tube <NUM> relative to the casing <NUM>.

During the further downward displacement of the syringe S, see <FIG>, the lower end of the tube <NUM> comes to rest against another stop surface AY2 on the holding component HO, which other stop surface AY2 is located on the lower end of the holding component HO. As a result, it is prevented that the lower end of the tube <NUM> is shifted downward past the lower end of the holding component HO.

<FIG> show how the syringe S was shifted to a lower end position in the holding component HO, wherein a flange FL on the syringe S comes to rest against the upper end of the casing <NUM> when the lower end position of the syringe S has been reached. As is apparent from <FIG>, cannula KA has now been shifted downward past the lower end of the holding component HO and the separation mechanism of the cannula remover can now carry out a separation of the cannula KA from the injection body SK.

Claim 1:
A device for increasing safety in conjunction with removal of a cannula (KA) from an injection body (SK) of a syringe, the device comprising:
- a tube (<NUM>) having a group of parallel longitudinal slots consisting of two diametrically disposed pairs of parallel slots (11A, 11B, 16A, 16B), wherein a flexible strip (<NUM>) is defined between each of two pairs of adjacent slots of the group of parallel longitudinal slots (11A, 11B, 16A, 16B);
- a casing (<NUM>) mounted on the tube (<NUM>) and provided with two internal recesses (<NUM>) extending in a longitudinal direction of the casing (<NUM>), wherein the casing (<NUM>) has a variable wall thickness in circumferential direction; and
- a holding component (HO) that is operable to receive the casing (<NUM>) along with the tube (<NUM>), wherein during downward displacement of the casing (<NUM>) and the tube (<NUM>) the casing (<NUM>) comes to rest against an internal first stop surface (AY1) of the holding component (HO) and during further downward displacement, the lower end of the tube (<NUM>) comes to rest against another stop surface (AY2) of the holding component (HO);
wherein the cannula (KA) is removable from the syringe (S) by a cannula removing separation mechanism,
characterized in that the tube (<NUM>) and the casing (<NUM>) are operable to rotate around a common longitudinally running central axis such that thicker wall parts of the casing (<NUM>) come to be located directly in front of the flexible strip (<NUM>) in the tube (<NUM>) and exert a clamping action on the flexible strip ( <NUM>) for removal of the cannula (KA) from the syringe (S), wherein the clamping action presses an internal heel (<NUM>) located on the inside of the flexible strip of the tube (<NUM>) into a track (SP) going round the front end of the injection body (SK) in the injection body (SK), thus providing clamping of the tube (<NUM>) relative to the injection body (SK).