Collection assembly or test tube for a small amount of a body fluid, comprising an extender element

A collection assembly for collecting a small amount of a body fluid, comprising:

• a sample container with a container wall, said container wall extending from a first open end to a second end, being limited by an outer surface and an inner surface and defining a longitudinal axis, and with a base, said base closing the second end of the container wall and surrounding a collecting chamber together with the container wall;
• and wherein
• the container wall comprises a first container wall section and a second container wall section adjacent thereto in the direction of the longitudinal axis;
• wherein
• the first container wall section is formed hollow-cylindrically with a first outer diametric dimension and is arranged starting out from the open end;
• and wherein
• the second container wall section comprises an at least sectionally smaller second diametric dimension with respect to the first outer diametric dimension of the first container wall section;
• and wherein
• a transition section is arranged between the first container wall section and the second container wall section;
• and further comprising:
• an extender element having a side wall, said side wall extending from a first open end to a second end, and having a base wall arranged to be adjacent to the second end, wherein the base wall of the extender element is calotte-shaped;
• and wherein
• the sample container at least partially projects into the first open end of the extender element with its second container wall section arranged at a distance from the first open end in the direction of the longitudinal axis;
• and further comprising:
• a coupling device with at least one first coupling element and with at least one second coupling element;
• wherein
• the at least one first coupling element is arranged or formed on the sample container and the at least one second coupling element is arranged or formed on the extender element;
• and wherein
• when the first and second coupling elements are in coupled engagement, the extender element is coupled to the sample container in a positively locked manner by means of a snap connection formed by the coupling elements establishing the collection assembly;
• wherein the second container wall section of the container wall of the sample container is formed hollow-conically;
• wherein the at least one first coupling element is arranged in the transition section between the first container wall section and the second container wall section of the container wall;
• wherein the side wall of the extender element between the first open end and the second end is formed hollow-cylindrically;
• and
• wherein the side wall is formed to be continuous and straight as seen in axial section between the first open end and the second end;
• wherein the at least one first coupling element is formed as a continuous peripheral first groove as well as the wall section of the side wall of the sample container adjoining thereon in the direction towards the base of the sample container;
• wherein a first side face of the first groove, said first side face facing the open end of the sample container, forms an abutment surface for an end face of the extender element in the region of its first open end and the first side face forms an axial abutment for the first end face of the extender element;
• wherein several support elements arranged distributed across the circumference are provided, said support elements being arranged on the outer surface of the second container wall section of the container wall and projecting beyond the outer surface towards the side facing away from the longitudinal axis;
• wherein the support elements are formed as webs, said webs having a particularly parallel longitudinal extent with respect to the longitudinal axis;
• wherein an outer envelope of the webs forming the support elements has a diameter, said diameter being equal to or slightly larger than an inner diameter of the side wall of the extender element in the region of its open end;
• wherein in the base wall of the extender element, at least one breakthrough is arranged, said at least one breakthrough perforating the base wall;
• and
• wherein the at least one breakthrough is arranged at a distance from the longitudinal axis in the radial direction and the base wall is formed continuously in the region of the longitudinal axis.