Protecting mechanism for blood sampling device

A protecting mechanism for a blood sampling device contains: a trigger unit and a switching assembly. The trigger unit includes a lancet holder, a triggering shaft, and a resilient element. The lancet holder has a launching portion, a first outer protrusion, a through orifice, and a first inner shoulder, wherein a bottom end of the triggering shaft moves in the through hole, and the triggering shaft has a first outer shoulder for engaging with the first inner shoulder of lancet holder, the resilient element is fitted with the triggering shaft and abuts against the lancet holder by ways of its bottom end. The switching assembly includes a fixing jacket having an abutting portion, a rotating tube having a first inner protrusion and two opposite second inner protrusions, and a driving sheath having two stopping sets, wherein each stopping set has two second outer protrusions.

FIELD OF THE INVENTION

The present invention relates to a blood sampling device, and more particularly to a protecting mechanism for the blood sampling device.

BACKGROUND OF THE INVENTION

A conventional blood sampling device is employed to sample patient's blood after inserting into skin, and its lancet is discarded after use.

However, the conventional blood sampling device is not provided with a protecting mechanism for preventing the lancet from injuring medical personnel, thus increasing using danger.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a protecting mechanism for a blood sampling device which prevents a removal of a lancet by using a switching assembly while triggering the lancet and avoids triggering the lancet while retracting the lancet.

To obtain the above objective, a protecting mechanism for a blood sampling device provided by the present invention contains: a trigger unit and a switching assembly.

The trigger unit includes a lancet holder, a triggering shaft, and a resilient element. The lancet holder has a launching portion and a first outer protrusion opposite to the launching portion, the lancet holder also has a through orifice defined therein and a first inner shoulder defined on a top end of the through orifice, wherein a bottom end of the triggering shaft moves in the through hole, and the triggering shaft has a first outer shoulder arranged on an outer wall thereof to engage with the first inner shoulder of lancet holder, the resilient element is fitted with the triggering shaft and abuts against the lancet holder by ways of its bottom end.

The switching assembly includes a fixing jacket, a rotating tube, and a driving sheath. The fixing jacket is fitted with the lancet holder and has an abutting portion, the rotating tube is rotatably fitted with the fixing jacket between a starting position and a retracting position, and the rotating tube has a first inner protrusion arranged on an inner wall thereof and has two opposite second inner protrusions formed on the inner wall thereof. The driving sheath is fitted on a top end of the triggering shaft and contacts with a top end of the resilient element, and the driving sheath has two stopping sets arranged on an outer wall thereof, wherein each stopping set has two second outer protrusions.

Preferably, the lancet holder further a cutout defined on the first outer protrusion, such that when the rotating tube is located at the starting position, the first inner protrusion of the rotating tube moves away from the cutout of the lancet holder to remove from the first outer protrusion of the lancet holder, and when the rotating tube is located at the retracting position, the first inner protrusion of the rotating tube extends into the cutout of the lancet holder to engage with the first outer protrusion of the lancet holder.

Preferably, the rotating tube further has a flexible pressing portion formed on the outer wall thereof, such that when the rotating tube is located at the starting position, the flexible pressing portion presses the launching portion of the lancet holder.

Preferably, the trigger unit further includes a connector fitted with the top end of the triggering shaft and abutting against the driving sheath.

Preferably, the top end of the triggering shaft extends out of the through orifice of the lancet holder and has a second outer shoulder above the first outer shoulder, the connector has a pushing member, and the pushing member has two opposite second inner shoulders arranged on an inner wall thereof to engage with the second outer shoulder of the triggering shaft, and the pushing member also has two opposite extensions extending outwardly from an outer wall thereof, wherein each extension contacts with the two second outer protrusions of each stopping set of the driving sheath.

Preferably, the connector has a housing, and the housing has an aperture and two opposite retainers formed on a peripheral wall of the aperture, wherein each extension has a locking portion for engaging with each retainer of the housing.

Preferably, the trigger unit further includes a cap and a returning spring, and the cap is fitted with the top end of the triggering shaft, the returning spring is fitted on the triggering shaft and is biased against the pushing member and the cap.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference toFIG. 1, a blood sampling device10according to a preferred embodiment of the present invention comprises a body12and a fitting tube14connected with a bottom end of the body12. Referring further toFIG. 2, a protecting mechanism18is mounted in the blood sampling device10and includes a trigger unit20and a switching assembly30.

The trigger unit20includes a lancet holder21, a triggering shaft22, a resilient element23, and a connector24.

The lancet holder21has a through orifice211defined therein to insert a lancet16, a first inner shoulder212defined on a top end of the through orifice211(as shown inFIG. 3), a first outer protrusion213formed on an outer wall thereof, a cutout214defined on the first outer protrusion213, and a launching portion215opposite to the first outer protrusion213.

As illustrated inFIGS. 2 and 3, the triggering shaft22is inserted into the through orifice211of the lancet holder21to trigger the lancet16, and a top end of the triggering shaft22extends out of the through orifice211of the lancet holder21and fits with a cap28. The triggering shaft22has a first outer shoulder221arranged on an outer wall thereof and has a second outer shoulder223above the first outer shoulder221, wherein the first outer shoulder221engages with the first inner shoulder212of the lancet holder21(as shown inFIG. 3), such that after the triggering shaft22is pulled, it drives the lancet holder21to move away from the lancet16.

The resilient element23is fitted with the triggering shaft22and abuts against a top end of the lancet holder21by ways of its bottom end, such that the lancet holder21is pushed by the resilient element23to drive the triggering shaft22to move toward the lancet16.

The connector24has a housing25, a pushing member26, and a returning spring27. With reference toFIGS. 2 and 4, the housing25has an aperture252for fitting with a top end of the body12and has two opposite retainers254formed on a peripheral wall of the aperture252. The pushing member26has a loop261fitted on the top end of the triggering shaft22and has two opposite second inner shoulders262arranged on an inner wall thereof to engage with the second outer shoulder223of the triggering shaft22. The pushing member26also has two opposite extensions263extending outwardly from an outer wall of the loop261, wherein each extension263has a locking portion264for engaging with each retainer254of the housing25, such that the pushing member26is mounted in the aperture252of the housing25. The returning spring27is fitted on the triggering shaft22and is biased against the loop261of the pushing member26and the cap28to push the triggering shaft22to move back to an original position.

The switching assembly30includes a fixing jacket40, a rotating tube50, and a driving sheath60.

The fixing jacket40is disposed on the bottom end of the body12and is fitted into the fitting tube14. The fixing jacket40has an opening42defined therein to fit with the lancet holder21and has an abutting portion44formed on an outer wall thereof to engage with the launching portion215of the lancet holder21, as shown inFIGS. 2 to 6.

The rotating tube50is rotatably fitted with the fixing jacket40and is defined between the body12and the fixing jacket40. The rotating tube50has a first inner protrusion51arranged on a middle section of an inner wall thereof and has two opposite second inner protrusions52formed on a top end of the inner wall thereof, such that when the rotating tube50is located at a starting position P1, as illustrated inFIGS. 2 and 3, the first inner protrusion51of the rotating tube50moves away from the cutout214of the lancet holder21to remove from the first outer protrusion213of the lancet holder21, hence the lancet holder21moves upwardly and downwardly in the opening42of the fixing jacket40. With reference toFIGS. 2 to 8, when the rotating tube50is located at a retracting position P2, the first inner protrusion51extends into the cutout214of the lancet holder21to engage with the first outer protrusion213of the lancet holder21, hence the lancet holder21does not move upwardly and downwardly in the opening42of the fixing jacket40.

The rotating tube50further has a flexible pressing portion53formed on the outer wall thereof and corresponding to the abutting portion44of the fixing jacket40.

The driving sheath60is fitted on the triggering shaft22and abuts against an internal rib122of the body12(as shown inFIG. 3), the driving sheath60has an end face62for contacting with a top end of the resilient element23and the loop261of the pushing member26(as illustrated inFIG. 3). The driving sheath60also has two stopping sets (i.e., each stopping set has two second outer protrusions64, as illustrated inFIG. 2) arranged on an outer wall thereof, wherein the two second outer protrusion64of each stopping set are defined between each second inner protrusion52of the rotating tube50and each extension263of the pushing member26, such that when the rotating tube50is located at the starting position P1, as shown inFIG. 4, the two second outer protrusions64of each stopping set of the driving sheath60are stopped by each second inner protrusion52of the rotating tube50, and then the driving sheath60does not move downwardly. Referring toFIG. 9, when the rotating tube50is located at the retracting position P2, the two second outer protrusions64of each stopping set of the driving sheath60are not stopped by each second inner protrusion52of the rotating tube50, and then the driving sheath60is pushed by each extension263of the pushing member26to move downwardly.

In operation, as shown inFIG. 3, the rotating tube50is rotated toward the starting position P1so that the lancet holder21moves upwardly and downwardly in the opening42of the fixing jacket40, and then the housing25of the connector24is pulled, as illustrated inFIG. 5, such that the connector24pushes the returning spring27to move upwardly by using the loop261of the pushing member26, and then the returning spring27pushes the cap28to move upwardly so that the triggering shaft22is driven by the cap28to move upwardly. In the meantime, the triggering shaft22pushes the lancet holder21by engaging the first outer shoulder221with the first inner shoulder212of the lancet holder21. Since the driving sheath60is fixed, the resilient element23is pressed by the lancet holder21, and when the launching portion215of the lancet holder21engages with the abutting portion44of the fixing jacket40, it is pressed by the flexible pressing portion53of the rotating tube50(as shown inFIG. 5) to release the connector24, hence the returning spring27pushes the pushing member26of the connector24, and then each extension263of the pushing member26contacts with the two second outer protrusions64of each stopping set of the driving sheath60, thus starting to trigger the lancet. Because the two second outer protrusions64of each stopping set of the driving sheath60are stopped by each second inner protrusion52of the rotating tube50, and each extension263of the pushing member26contacts with the two second outer protrusions64of each stopping set of the driving sheath60, as shown inFIG. 4, even though the connector24is pressed, the triggering shaft22does not operate, thus avoiding retracting the lancet.

When starting trigger the lancet, a starting switch124of the body12is pressed by user's finger (as illustrated inFIGS. 2 to 7) so that the starting switch124presses the flexible pressing portion53of the rotating tube50, and the flexible pressing portion53presses the abutting portion44of the lancet holder21, hence the abutting portion44disengages from the launching portion215of the lancet holder21, the resilient element23pushes the lancet holder21to drive the triggering shaft22by engaging the first inner shoulder212of the lancet holder21with the first outer shoulder221of the triggering shaft22, as illustrated inFIG. 7, thus triggering the lancet16.

As desiring to retract the lancet, the fitting tube14is removed to expose the lancet16, and the rotating tube50is rotated toward the retracting position P2, as shown inFIG. 8, then the lancet16is inserted into a storing sleeve (not shown). It is to be noted that the lancet holder21does not move, because it is limited by the rotating tube50. In addition, the driving sheath60is not stopped by the rotating tube50(as shown inFIG. 9), so while pressing the connector24, the pushing member26pushes the driving sheath60and the triggering shaft22downwardly, such that the triggering shaft22pushes the lancet16out of the through orifice211of the lancet holder21. With reference toFIG. 10, after retracting the lancet, the connector24is released so that the returning spring27pushes the triggering shaft22back to the through hole211of the lancet holder21. In the meantime, the lancet16is fixed in the storing sleeve so that it is discarded with the storing sleeve. Referring toFIG. 8, during retracting the lancet, since the lancet holder21engages with the rotating tube50, even though the triggering shaft22is pulled by the connector24, the lancet holder21cannot be pulled toward the starting position, thus avoiding triggering the lancet.

Thereby, the protecting mechanism18of the present invention prevents a removal of the lancet by using the switching assembly30while triggering the lancet and avoids triggering the lancet while retracting the lancet.