Decapping of screw cap test tubes
Decapping system and methods of performing a decapping process for screw cap test tubes. In an embodiment, a method comprises loading a test tube rack in a rack holder that holds the test tube rack stationary, where the test tube rack holds the screw cap test tubes aligned in a row. The method further comprises clamping the row of the screw cap test tubes between a pair of jaw members of a row clamp, where clamp surfaces of the jaw members apply a force to opposing sides of the row of the screw cap test tubes. The method further comprises successively contacting screw caps of the screw cap test tubes in the row with a rotating bit of a decapper tool to spin the screw caps in a loosening direction.
1 . A method of performing a decapping process for screw cap test tubes each comprising a screw cap having threads configured to engage with threads of a threaded test tube, the method comprising:
loading a test tube rack in a rack holder of a retention apparatus that holds the test tube rack stationary, wherein the test tube rack holds the screw cap test tubes aligned in a row;
clamping the row of the screw cap test tubes between a pair of jaw members of a row clamp of the retention apparatus, wherein clamp surfaces of the jaw members apply a force to opposing sides of the row of the screw cap test tubes, and wherein the retention apparatus holds the test tube rack at an angle of about 30-45 degrees relative to a vertical plane; and
successively contacting screw caps of the screw cap test tubes in the row with a rotating bit of a decapper tool to spin the screw caps in a loosening direction, wherein
successively contacting the screw caps comprises contacting each screw cap of the screw caps with the rotating bit at a non-zero angle relative to a spin axis of the screw cap.
2 . The method of claim 1 further comprising:
unclamping the row of the screw cap test tubes from the jaw members; and
removing the test tube rack.
3 . The method of claim 1 wherein successively contacting the screw caps comprises:
contacting edges of the screw caps with the rotating bit.
4 . The method of claim 1 wherein:
the decapper tool comprises a handheld tool; and
successively contacting the screw caps comprises:
moving, by a human operator, the handheld tool along a process path to engage the screw caps one-by-one.
5 . The method of claim 1 wherein:
the non-zero angle is in a range of about 30-45 degrees to the spin axis of the screw cap.
6 . The method of claim 1 wherein successively contacting the screw caps comprises:
iteratively performing:
contacting a screw cap of a screw cap test tube in the row with the rotating bit at the non-zero angle to the spin axis;
moving the rotating bit using an upward motion while in contact with the screw cap to lift the screw cap; and
moving the decapper tool to a next successive screw cap in the row.
7 . The method of claim 1 wherein clamping the row of the screw cap test tubes comprises:
activating a pneumatic actuator to move at least one of the jaw members.
8 . The method of claim 1 wherein clamping the row of the screw cap test tubes comprises:
activating a hydraulic actuator to move at least one of the jaw members.
9 . The method of claim 1 wherein clamping the row of the screw cap test tubes comprises:
activating an electric actuator to move at least one of the jaw members.
10 . The method of claim 1 wherein clamping the row of the screw cap test tubes comprises:
contacting a graspable portion of the screw cap test tubes between a top surface of the test tube rack and a bottom end of the screw caps with the clamp surfaces of the jaw members.
11 . The method of claim 1 further comprising:
conveying the screw caps removed from the screw cap test tubes to a receptacle with a cap chute.
12 . The method of claim 1 wherein clamping the row of the screw cap test tubes comprises:
applying the force to the opposing sides of the row of the screw cap test tubes with the jaw members in a pressure range that prevents rotation of the screw cap test tubes.
13 . A method of performing a decapping process for screw cap test tubes each comprising a screw cap having threads configured to engage with threads of a threaded test tube, the method comprising:
loading a test tube rack in a rack holder of a retention apparatus that holds the test tube rack stationary, wherein the test tube rack holds the screw cap test tubes aligned in a row;
clamping the row of the screw cap test tubes between a pair of jaw members of a row clamp of the retention apparatus, wherein the jaw members include clamp surfaces that contact opposing sides of the row of the screw cap test tubes, and wherein the retention apparatus holds the test tube rack at an angle of about 30-45 degrees relative to a vertical plane; and
moving a decapper tool along a process path while the jaw members immobilize the screw cap test tubes;
wherein along the process path, a rotating bit of the decapper tool successively contacts each screw cap of the screw cap test tubes in the row at a non-zero angle to a spin axis of the screw cap to impart an unscrewing rotation to the screw cap.
14 . A decapping system, comprising:
a retention apparatus configured to receive a test tube rack that holds screw cap test tubes aligned in a row, the retention apparatus comprising:
a row clamp comprising a pair of jaw members having clamp surfaces configured to contact opposing sides of the row of the screw cap test tubes; and
a decapper tool comprising a rotating bit configured to successively contact screw caps of the screw cap test tubes in the row to spin the screw caps in a loosening direction, wherein
the retention apparatus is configured to hold the test tube rack at an angle of about 30-45 degrees relative to a vertical plane.
15 . The decapping system of claim 14 , wherein:
the clamp surfaces of the jaw members are configured to contact a graspable portion of the screw cap test tubes between a top surface of the test tube rack and a bottom end of the screw caps.
16 . The decapping system of claim 14 , wherein the row clamp further comprises:
a pliable material disposed along at least one of the clamp surfaces.
17 . The decapping system of claim 14 , wherein the row clamp further comprises:
a pneumatic actuator configured to move at least one of the jaw members.
18 . The decapping system of claim 14 , wherein the retention apparatus further comprises:
a cap chute configured to convey the screw caps removed from the screw cap test tubes to a receptacle.
19 . The decapping system of claim 14 , wherein:
the clamp surfaces are disposed at the angle of about 30-45 degrees relative to the vertical plane.
20 . The decapping system of claim 14 , wherein:
the rotating bit comprises:
a hollow cylindrical member with surface features disposed along an inner cylindrical surface of the hollow cylindrical member; and
an inner diameter of the hollow cylindrical member is between about 0.5 and 1.5 times a diameter of the screw caps.