Technical field

The present invention relates to a cutting tool for cutting tube strips comprising two or more sample vessels, as defined in claim 1 .

Background

Small sample vessels are needed for handling and analyzing various samples in laboratories. To facilitate handling of a large number of samples, the sample vessels are often implemented in the form of microplates. A microplate contains several wells, into which the samples are placed. The wells are arranged in rows. The number of wells in a microplate can be, for instance, 24, 48, 96 or 384. Even larger microplates exist.

As an alternative to microplates, the sample vessels can be small tubes that are connected to each other to form a tube strip. There are also microplates that can be divided into tube strips. This kind of solutions are often used in PCR methods.

Typically, the tube strips are used as unbroken units. However, in some cases there is a need to break tube strips into portions or detach individual sample vessels from the tube strips. Pliers can be used for cutting the tube strips made of a plastic material, but the use of pliers is clumsy and the detached tubes may fall from the user’s hands. Also the forces needed to cut through the material between the tubes may be very high, causing stress to the hands. There is also a risk of cutting into the user’s hand. Pliers may also accidentally pierce through the tube wells if the cutting line is not correct and pieces of material may be removed during the cutting.

Summary of the invention

An object of the present invention is to provide an improved cutting tool for cutting tube strips comprising two or more sample vessels. The characterizing features of the cutting tool according to the invention are defined in claim 1 .

The cutting tool according to the invention comprises a body, tube strip holding means configured to hold a tube strip in a fixed position relative to the body of the cutting tool, the tube strip holding means comprising a first holding portion that is configured to hold a sample vessel of the tube strip and a second holding portion that is configured to hold another sample vessel of said tube strip, a blade unit comprising a blade, the blade unit being configured to be moveable relative to the body in a direction that is perpendicular to the longitudinal direction of the tube strip hold by the tube strip holding means and to cut the tube strip between the first holding portion and the second holding portion, a lever that is pivotably connected to the body via a pivot axis, and a connecting element connecting the lever to the blade unit, wherein rotation of the lever about the pivot axis is configured to move the blade unit towards the tube strip holding means to cut the tube strip hold by the tube strip holding means.

The cutting tool according to the invention allows tube strips to be cut into two pieces in a convenient way. Due to the tube strip holding means, the user of the cutting tool does not need to hold the tube strip by hand while cutting it into two pieces. Because of the first holding portion and the second holding portion, the separated pieces of the tube strip do not fall but are retained by the holding portions. The lever allows exerting a sufficient force on the tube strip. This is beneficial especially in case the sample vessels are connected to each other by hard material, such as polycarbonate. The cutting tool according to the invention allows tube strips to be cut into two pieces in a reliable way.

According to an embodiment of the invention, the cutting tool comprises a rail for connecting the blade unit slideably to the body. The rail thus supports the blade unit and allows it to move linearly in a predetermined fashion. The cutting point and line is thus kept constant and set automatically. Wrong positioning of the cutting point and line could result in breakage of the vessels and/or too little support area around the vessel openings.

According to an embodiment of the invention, the first holding portion and the second holding portion are configured to hold consecutive sample vessels of the tube strip. This allows a tube strip to be cut between any two sample vessels to separate a single sample vessel from the tube strip or to cut the tube strip into two pieces of desired lengths.

According to an embodiment of the invention, the tube strip holding means comprise a first hole for receiving a sample vessel of the tube strip and a second hole for receiving another sample vessel of said tube strip. The tube strip can thus be easily inserted into the cutting tool for cutting and the pieces can be easily removed from the cutting tool after cutting.

According to an embodiment of the invention, the tube strip holding means are integral part of the body.

According to an embodiment of the invention, the cutting tool comprises a support surface that is arranged in the moving direction of the blade unit behind the tube strip holding means and configured to support the tube strip on both sides of the blade when the tube strip is being cut. When the blade moves forward to cut the tube strip, the support surface forms a counter-force for the force of the blade. This helps keeping the tube strip in place. The support surface can be an integral part of the body.

According to an embodiment of the invention, the cutting tool comprises a first shield portion arranged, seen in the moving direction of the blade unit, on a first side of the blade and a second shield portion arranged on a second side of the blade, and the blade is configured to move between the first shield portion and the second shield portion to protect the user of the cutting tool from the blade. The shield portions make the use of the cutting tool safe.

According to an embodiment of the invention, the blade unit is configured to be moveable between a retracted position, where a tube strip can be inserted into the tube strip holding means, and a forward position, where the tube strip is cut, and the cutting edge of the blade is configured to remain between the first and the second shield portions in both the retracted position and the forward position. This protects the user in any position of the cutting tool.

According to an embodiment of the invention, the first and second shield portions are integral part of the body.

According to an embodiment of the invention, the blade unit comprises a shield portion extending over the blade and being configured such that a gap formed between the shield portion of the blade unit and each of the first shield portion and the second shield portion is less than 5 mm. The shield portion of the blade unit provides additional protection for the user.

According to an embodiment of the invention, the blade unit comprises a portion that is configured to extend at least partly over the tube strip before the blade contacts the tube strip to prevent the tube strip from raising from the tube strip holding means. The blade unit thus comprises a portion which is located forward from the cutting edge of the blade. During the forward movement of the blade unit, before the blade is in a position where it starts cutting the tube strip, the portion moves into a position, where it at least partly covers the tube strip. This ensures that the tube strip is kept positioned such that it is cut at a correct position.

According to an embodiment of the invention, the lever comprises a connection portion and a handle portion, the connection portion being connected to the body via the pivot axis and to the connecting element via a second pivot axis, and the handle portion being configured to be operated by the user of the cutting tool.

According to an embodiment of the invention, the handle portion of the lever is configured to be essentially parallel to the moving direction of the blade unit when the blade unit has been moved into a position where the tube strip has been cut. This makes the cutting tool compact in a closed position.

Brief description of the drawings

Embodiments of the invention are described below in more detail with reference to the accompanying drawings, in which

Fig. 1 shows a perspective view of a cutting tool according to an embodiment of the invention in an open state and a tube strip,

Fig. 2 shows the cutting tool of Fig. 1 with the tube strip inserted into the cutting tool,

Fig. 3 shows the cutting tool in a closed state,

Fig. 4 shows a side view of the cutting tool in the open state,

Fig. 5 shows a side view of the cutting tool in the closed state,

Fig. 6 shows a cross-sectional view of the cutting tool in the open state,

Fig. 7 shows a cross-sectional view of the cutting tool in the closed state and

Fig. 8 shows a top view of the body and blade unit of the cutting tool. Detailed of embodiments of the invention

The cutting tool 1 according to the invention is configured to cut tube strips 2 comprising two or more sample vessels 2a. In the figures is shown a tube strip 2 comprising eight sample vessels 2a. The sample vessels 2a can be used, for instance, for containing samples that are treated by polymerase chain reaction (PCR) methods. The tube strip 2 is made of a plastic material. The sample vessels 2a of the tube strip 2 are connected to each other from their upper ends by thin strips. The lower ends of the sample vessels 2a are free ends. Two consecutive sample vessels 2a can thus be separated from each other by cutting the strip connecting the two sample vessels 2a. The tube strip 2 can be made of more than one material. For instance, the sample volumes of the sample vessels 2a can be made of a different material than the parts connecting the sample vessels 2a. For instance, the connecting parts and upper parts of the sample vessels 2a could be made of polycarbonate, which is a hard plastic material and makes the tube strips 2 rigid. This ensures that the upper parts of the tube strip retain their shape when being handled. The sample volumes could be made of polypropylene, which is a softer material and helps forming a good thermal contact between the sample volumes and a heat block.

The cutting tool 1 is a manually operable tool. A user of the cutting tool 1 thus inserts the tube strip 2 to be cut into the cutting tool 1 and operates the cutting tool 1 to cut the tube strip 2.

The cutting tool 1 comprises a body 3. The body 3 can be made of, for instance, a metal or an alloy. The body 3 could be made of, for instance, aluminum. Alternatively, the body 3 could be made of, for instance, a composite material. In the embodiment of the figures, the body 3 is a one-piece part. However, the body 3 could also comprise several parts. If the body 3 was made of several parts, different parts could be made of different materials. In the embodiment of the figures, the body 3 is configured to be supported against a desk or a similar surface. As the cutting tool 1 can be supported against a horizontal surface, the user of the tool 1 can easily exert a sufficient force on the moving parts of the cutting tool 1 , and even tube strips 2 comprising harder materials can thus be easily cut.

The cutting tool 1 further comprises tube strip holding means 4, 5. The tube strip holding means 4, 5 are configured to hold a tube strip 2 in a fixed position relative to the body 3 of the cutting tool 1 . The tube strip holding means 4, 5 thus hold the tube strip 2 while it is being cut. After cutting, the pieces of the tube strip 2 can be removed from the cutting tool 1 .

The tube strip holding means 4, 5 comprise a first holding portion 4 that is configured to hold a sample vessel 2a of the tube strip 2 and a second holding portion 5 that is configured to hold another sample vessel 2a of the tube strip 2.

The cutting tool 1 comprises a blade unit 6 comprising a blade 11 . The blade unit 6 is configured to be moveable relative to the body 3 in a direction that is perpendicular to the longitudinal direction of a tube strip 2 hold by the tube strip holding means 4, 5 and to cut the tube strip 2 between the first holding portion 4 and the second holding portion 5. Rotational movement of the blade unit 6 is prevented, and the blade unit 6 can move only linearly between a retracted position and a forward position. In the use position of the cutting tool 1 , the moving direction of the blade unit 6 is horizontal.

The cutting tool 1 further comprises a lever 7 that is pivotably connected to the body 3 via a pivot axis 8, and a connecting element 9 connecting the lever 7 to the blade unit 6.

Rotation of the lever 7 about the pivot axis 8 is configured to move the blade unit 6 towards the tube strip holding means 4, 5 to cut a tube strip 2 hold by the tube strip holding means 4, 5. The connecting element 9 is configured to convert the rotational movement of the lever 7 into a linear movement of the blade unit 6. The blade 11 has a cutting edge facing the moving direction of blade unit 6. The user of the cutting tool 1 can thus operate the lever 7 to move the blade unit 6 and to cut a tube strip 2 that has been inserted into the cutting tool 1 .

The cutting tool 1 has an open position and a closed position. In the open position, which is shown in figures 1 , 2, 4 and 6, a tube strip 2 can be inserted into the cutting tool 1 . When the cutting tool 1 is moved from the open position to the closed position, which is shown in figures 3, 5 and 7, the tube strip 2 is cut. The pieces of the cut tube strip 2 can be removed from the cutting tool 1 by moving it back to the open position or at least into a partly open position. The tube strip holding means 4, 5 are configured to hold the sample vessels 2a in an upright position. The blade unit 6 is configured to move in a horizontal direction. The pivot axis 8 connecting the lever 7 to the body 3 is a horizontal axis. The axial direction of the pivot axis 8 is perpendicular to the moving direction of the blade unit 6.

In the open position of the cutting tool 1 , the blade unit 6 is in a retracted position. The lever 7 is in a raised position. As a user pulls or pushes down the lever 7, the connecting element 9 connected to the lever 7 and to the blade unit 6 pushes the blade unit 6 towards the tube strip 2 the blade 11 ahead. As the blade unit 6 moves forward, the blade 11 eventually contacts the strip connecting two consecutive sample vessels 2a of the tube strip 2. In the closed position of the cutting tool 1 , the blade unit 6 is in a forward position. In the forward position of the blade unit 6, the cutting edge of the blade 11 has moved through the strip connecting the two consecutive sample vessels 2a of the tube strip 2.

In the embodiment of the figures, the cutting tool 1 comprises a rail 10 for connecting the blade unit 6 slideably to the body 3. The blade unit 6 can thus be moved linearly along the rail 10 between the retracted position and the forward position.

In the embodiment of the figures, the first holding portion 4 and the second holding portion 5 are configured to hold consecutive sample vessels 2a of the tube strip 2. This allows the tool 1 to be used for removing individual sample vessels 2a from the strip tube 2.

In the embodiment of the figures, the tube strip holding means 4, 5 are an integral part of the body 3. However, the tube strip holding means 4, 5 could also be arranged in one or more separate parts that are attached to the body 3. In the embodiment of the figures, the tube strip holding means 4, 5 comprise a first hole 4 for receiving a sample vessel 2a of the tube strip 2 and a second hole 5 for receiving another sample vessel 2a of the tube strip 2. In the embodiment of the figures, a slot 12 is arranged between the first holding portion 4 and the second holding portion 5 of the tube strip holding means. The blade 11 of the blade unit 6 can move in the slot 12 to cut the tube strip 2. The cutting tool 1 comprises a support surface 18 that is arranged in the moving direction of the blade unit 6 behind the tube strip holding means 4, 5 and configured to support the tube strip 2 on both sides of the blade 11 when the tube strip 2 is being cut. The support surface 18 cooperates with the strips connecting the sample vessels 2a from their upper ends. When the blade 11 moves forward to cut the tube strip 2, the support surface 18 forms a counterforce for the force of the blade 11 . This helps keeping the tube strip 2 in place. In the embodiment of the figures, the support surface 18 is a vertical surface. In the embodiment of the figures, the support surface 18 is an integral part of the body. The slot 12 extends beyond the support surface 18 and divides the support surface 18 into two portions. The cutting edge of the blade 11 can thus move past the support surface 18.

In the embodiment of the figures, the support surface 18 is formed by arranging the upper end of the tube strip holding means 4, 5 at a lower level than the upper surface of the body 3 behind the tube strip holding means 4, 5. A step is thus formed behind the tube strip holding means 4, 5 and the step forms the support surface 18. The rail 10, blade unit 6, blade 11 and slot 12 are preferably positioned along the longitudinal central axis of the tool, i.e. in the central line of the tool. The tube strip holding means 4 and 5 are preferably positioned symmetrically away from the central line so that when the tube strip 2 is held within the cutting tool 1 , the blade cutting line is in the middle of the part connecting two consecutive sample vessels 2a. This provides maximal tolerance against accidental breaking of the sample vessels 2a caused by cutting too near the opening area of a sample vessel 2a.

The cutting tool 1 is preferably configured to allow the cut pieces of the tube strip 2 to be pushed out from the tube strip holding means 4, 5. In the embodiment of the figures, the first and the second holding portions 4, 5 are through- holes. The holes 4, 5 open on the lower side of the cutting tool 1 into a cavity 17 of the body 3. That allows the sample vessels 2a that are placed into the tube strip holding means 4, 5 to be pushed out of the cutting tool 1 .

In the embodiment of the figures, the lever 7 is connected to the body 3 from a first end of the lever 7. The lever 7 comprises a connection portion 7a and a handle portion 7b. The pivot axis 8 connects the lever 7 to the body 3 of the cutting tool 1 from a first end of the connection portion 7a. A second pivot axis 15 connects the connecting element 9 to the lever 7. The second pivot axis 15 is arranged at a second end of the connection portion 7a of the lever 7. The handle portion 7b of the lever 7 is configured to be operated by the user of the cutting tool 1 . A third pivot axis 16 connects the connecting element 9 to the blade unit 6. In the embodiment of the figures, the cutting tool 1 is configured so that in the closed position the handle portion 7b of the lever 7 is substantially horizontal.

In the embodiment of the figures, the handle portion 7b of the lever 7 is substantially perpendicular to the connection portion 7a. The angle between the connection portion 7a and the handle portion 7b could be in the range of 80- 100 degrees. In the closed position of the cutting tool 1 the connection portion 7a of the lever 7 is substantially vertical.

The handle portion 7b of the lever 7 is preferably longer than the connection portion 7a of the lever 7. The length of the handle portion 7b could be, for instance, at least 300 percent of the length of the connection portion 7a. This ensures that even a small force exerted on the handle portion 7b is sufficient for cutting the tube strip 2.

In the embodiment of the figures, the cutting tool 1 comprises a first shield portion 13 arranged on a first side of the blade 11 and a second shield portion 14 arranged on a second side of the blade 11 . The blade 11 is configured to move between the first shield portion 13 and the second shield portion 14 to protect the user of the cutting tool 1 from the blade 11 . In the embodiment of the figures, the first shield portion 13 and the second shield portion 14 are integral parts of the body 3. However, the cutting tool 1 could also be provided with separate parts for forming the shield portions 13, 14. The cutting tool 1 is configured such that the cutting edge of the blade 11 remains between the first and second shield portions 13, 14 both in the retracted position and the forward position of the blade unit 6. In the embodiment of the figures, also the frame of the blade unit 6 is configured to move partly between the shield portions 13, 14.

In the embodiment of the figures, the blade unit 6 comprises a shield portion 6a extending over the blade 1 1 and being configured to move above the first and the second shield portions 13, 14. The gap formed between the shield portion 6a of the blade unit 6 and the first and second shield portions 13, 14 is configured to be less than 5 mm. With the narrow gaps, the user of the cutting tool 1 is protected from the blade 11 .

In the embodiment of the figures, the blade unit 6 comprises a portion 6b that is configured to extend during cutting movement of the blade unit 6 at least partly over the tube strip 2 before the blade 11 contacts the tube strip 2 to prevent the tube strip 2 from raising from the tube strip holding means 4, 5. This ensures that the tube strip 2 is hold in place during cutting and it is cut at a correct location. The cutting tool 1 is dimensioned so that the distance between the upper side of the tube strip 2 and the portion 6b of the blade unit 6 is sufficiently small to allow only a minor upward movement of the tube strip 2.

The cutting tool 1 according to the embodiment shown in the figures can be used for cutting a tube strip 2 between any two consecutive sample vessels 2a. It can thus be used for separating a single sample vessel 2a from an end of the tube strip 2 or to divide a tube strip 2 into two parts of selected lengths.

In many applications, there is a need to close the sample vessels 2a. Each sample vessel 2a could be closed with an own cap, but in case of microplates and tube strips, it is often practical to use cap strips. A cap strip comprises several caps connected to each other and thus allows sealing a row of sample vessels using a single closure element. A cap strip can be configured to have as many caps as the respective tube strip 2 has sample vessels 2a. The cutting tool 1 according to the invention could be used for cutting tube strips 2 closed by cap strips. The cutting tool 1 could thus cut also the cap strip closing the sample vessels 2a of the tube strip 2.

It will be appreciated by a person skilled in the art that the invention is not limited to the embodiments described above, but may vary within the scope of the appended claims.