Field of invention

The present invention relates to a moving mechanism for insertion and retrieval of a sample holder for sample vials in a sample isothermal calorimeter with horizontal sample insertion and retrieval, where the mechanism comprises a connecting means with a first part belonging to a moving member and a second part belonging to the sample holder, and where the connecting means is adapted to connect the moving member with the sample holder.

Description of background art

Patent publication WO 2007/139498 discloses an example of parallel sample isothermal calorimetry performed using microtiter plate layout and horizontal sample insertion which requires a mechanism to insert the sample holder to the equilibrium and measurement positions respectively. This same mechanism also performs retrieval of the sample holder after measurement. The mechanism for sample holder insertion and retrieval must be reliable.

Summary of the present invention

Problems

Isothermal calorimetry in the micro Watt level requires a tightly controlled temperature with minimal fluctuations. Inserting and retrieving, or moving, the multi vial sample holder traditionally requires a mechanical coupling between the sample holder and the moving mechanism.

Mechanical coupling between the sample holder and the moving

mechanism imposes a risk of transferring heat between the moving mechanism and the sample holder in either direction thus potentially disturbing the integrity of the measurement.

The moving mechanism must support both insertion and retrieval of samples without physical contact between the mechanism and the sample holder at the measurement position.

Solution From the standpoint of a moving mechanism according to the field of invention and with the purpose of solving one or more of the above mentioned problems, the present invention teaches that the first part comprises at least one magnet, and that the second part is a magnetic surface.

It is proposed that the first part comprises at least one retractable rod and that the at least one magnet is fastened at the end of the retractable rod. The retractable rod is adapted to:

- retract the magnet to a position from a tip of the first part that exceeds the distance of the magnetic field, thus preventing magnetic coupling between the magnet and the magnetic surface and allowing only physical contact to push when insertion is performed, and

- reposition the magnet to a distance from the tip allowing magnetic coupling between the magnet and the magnetic surface to drag when retrieval is performed.

At least the section of the sample holder comprising the second part is made out of a non-magnetic material.

With the purpose of getting a controlled and reliable movement it is proposed that the first part comprises two or more magnets, in which case the magnetic surface is wide enough to enable magnetic coupling with all magnets, or is may be divided into several magnetic surfaces, where each surface is positioned to enable magnetic coupling with one or more magnets.

Different materials may be used to form the connecting means. The at least one magnet may be a high-powered miniature neodymium based magnet, and the magnetic surface may be an iron based plate.

With the purpose of preventing any kind of heat transfer between the moving member and the sample holder, and yet maintaining a rigid construction of the sample holder, it is proposed that at least the non-magnetic material of the sample holder is made out of plastic or aluminum. Also for the reason of preventing any kind of heat transfer between the moving member and the sample holder it is proposed that the tip of the moving member is made out of plastic or aluminum.

Advantages The advantages of a moving mechanism according to the present invention are the possibility to place the sample holder in the different equilibrium and measurement positions of the calorimeter with a moving member where it is easy to make a connection with the sample holder in order to push or pull the sample holder and to disconnect and withdraw from the sample holder in order not to disturb the integrity of the measurement.

Only limited physical contact to perform insertion or retrieval of the sample holder is required without any heat transfer between the sample holder and moving member and without physical contact during measurement.

Brief description of the drawings

A moving mechanism according to the present invention will now be described in detail with reference to the accompanying drawings, in which:

Figure 1 is a schematic and simplified illustration of a moving

mechanism in a position for insertion of a sample holder, Figure 2 is a schematic and simplified illustration of a moving

mechanism in a position for retrieval of a sample holder, and Figure 3 is a schematic and simplified illustration of an embodiment with one magnetic surface adapted to function with several magnets.

Description of embodiments as presently preferred

The present invention will now be described with reference to figure 1 showing a moving mechanism 1 for insertion and retrieval of a sample holder 2 in a calorimeter with horizontal sample insertion and retrieval.

The mechanism 1 comprises a connecting means A with a first part 31 belonging to a moving member 3 and a second part 21 belonging to the sample holder 2, and where the connecting means A is adapted to connect the moving member 3 with the sample holder 2.

The first part 31 comprises two magnets 41 , 42 on retractable rods 31 a, 31 b and the second part 21 is a magnetic surface 21 a, 21 b, such as an iron based plate. Figure 1 shows that when insertion is performed the magnets 41 , 42 are retracted to a position P1 where the distance d1 to a tip 32 of the moving member 3 exceeds the distance of the magnetic field. The sample holder 2 can thus be moved by a forward pushing movement into equilibrium and sample measurement positions respectively in the calorimeter and the connecting means A is made out of a physical connection between the tip 32 of the moving member 3 and the sample holder 2.

After positioning in the measurement position the moving member is retracted to a distance where no physical contact or heat transfer can occur between the moving member 3 and the sample holder 2.

Figure 2 shows that upon retrieval of the sample holder 2 the moving member 3 is adapted to reposition the magnets 41 , 42 to a position P2 where the distance d2 from the tip 32 is within the distance of the magnetic field, thus allowing magnetic coupling between the magnets 41 , 42 and the magnetic surface 21 a, 21 b, and thus allowing for a horizontal retrieval of the sample holder 2.

The net result is a moving mechanism 1 allowing insertion and retrieval of the sample holder 2 without physical contact during measurement.

The invention covers the general use of magnetic coupling for sample holder retrieval in multi-channel calorimetry.

The number of magnets 41 , 42 are two in the exemplifying embodiments of figures 1 and 2, however, it should be understood that the number of magnets can range from 1 to n as indicated in figure 3, where at least two magnets will provide a controlled and reliable movement of the sample holder 2.

The magnetic material includes but not limited to neodymium high power magnets.

It is proposed that at least the section 22 of the sample holder 2

comprising the second part 21 is made out of a non-magnetic material, such as plastic or aluminum.

Figures 3 shows an embodiment where several magnets 41 , 42, 4n are used and where the magnetic surface 21 c is wide enough to enable magnetic coupling with all magnets.

Figures 1 and 2 shows one embodiment where the magnetic surface 21 a, 21 b is divided into several magnetic surfaces, which in the figures is two magnetic surfaces 21 a, 21 b, to match the two magnets 41 , 42, and where each surface is positioned to enable magnetic coupling with one or more magnets.

It is proposed that at least the tip 32 of the moving member is made out of plastic or aluminum. It will be understood that the invention is not restricted to the aforede- scribed and illustrated exemplifying embodiments thereof and that modifications can be made within the scope of the invention as defined by the accompanying Claims.