CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. § 119 of European Application No. 18 171 314.0 filed May 8, 2018, the disclosure of which is incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device and to a method for cutting-to-length surgical suture material so as to position the beginning of a thread from surgical suture material in a reproducible manner and to render said thread to a defined cut-off length in a flexible manner. A continuous thread of surgical suture material can thus be shortened to a desired length by means of such a device. The surgical suture material herein can be fastened to a surgical needle or else be present as a loose thread.

2. Description of the Related Art

Devices for cutting-to-length surgical suture material are known. Said devices typically have a thread spool having a continuous thread of surgical suture material. The desired length of surgical suture material is drawn off from the thread spool by means of a thread advancing gripper that is guided in a linear manner in a (horizontal or vertical) transport direction. This drawing-off from the thread spool is in part controlled by way of a so-called dancer mechanism. The surgical suture material is subsequently cut by means of a cutting unit at the desired location.

The leading thread end of the surgical suture material typically has to be advanced to a fixed position, since the connection of the leading thread end to the surgical needle can be performed exclusively at this defined position. Adapting said joining position to dissimilar thread lengths is impossible in terms of machine technology. Therefore, the maximum possible length of surgical suture material is typically always present as a free thread length. Adapting the device to dissimilar thread lengths in this instance is performed by a displacement of the cutting unit in the longitudinal direction of the free thread. Accordingly, the repositioning range of the thread advancing gripper is also adapted with a view to the start position of the latter. Depending on the position of the cutting unit, the surgical suture material is then cut at a specific spacing from the thread spool. Cutting machines of this type therefore have a correspondingly long construction length. Moreover, the free thread length is comparatively large such that significant vibrations can arise in the region of the unwound surgical suture material. This can impede both the threading of the thread into the needle, as well as the actual cutting of the thread.

SUMMARY OF THE INVENTION

Proceeding from said known prior art, the invention is based on the object of specifying an improved device for cutting-to-length surgical suture material to dissimilar thread lengths, said device enabling an ideally compact construction mode.

These and other objects are accomplished by a device for cutting surgical suture material according to one aspect of the invention and by a method according to another aspect of the invention. Expedient refinements of the invention are discussed below.

The device according to the invention for cutting surgical suture material possesses a thread spool having a continuous thread of the surgical suture material as well as a thread advancing gripper for drawing off a defined length of surgical suture material. Moreover, a cutting unit for cutting the surgical suture material is present. According to the invention, a deflection installation by way of which the surgical suture material can be placed along a secondary axis so as to be angled to the primary transport direction in at least one open loop is provided. The length of said open loop herein can be variably adjusted. The cutting unit herein is positioned between the deflection installation and the thread spool for the continuous thread.

On account of the presence of the deflection installation it is no longer necessary for the cutting unit to be configured so as to be displaceable in the longitudinal direction. Rather, the deflection installation enables dissimilar lengths of surgical suture material to be unwound and to be cut off. The dissimilar lengths herein are determined by the length of the open loop. Therefore, the free thread length of the surgical suture material does also no longer have to correspond to the maximum possible thread length, but now only to the minimum thread length required. In this way, the device can be reduced to approximately one third of the length required to date. The device according to the invention can therefore be constructed so as to be significantly shorter and thus also significantly more compact.

The surgical suture material by way of the deflection installation can preferably be placed so as to be perpendicular to the primary transport direction in at least one open loop. Sufficient space is typically available perpendicularly to the longitudinal axis of the unwound thread, such that such an open loop can be configured within the device according to the invention. The open loop can therefore be integrated in the device in an optimal manner, such that said device can be constructed so as to be compact.

In one embodiment which in terms of construction is particularly preferable, the deflection installation can have a front and a rear deflection unit, each being configured so as to be stationary. One or a plurality of repositionable compensation rollers can be present between the two stationary deflection units. The at least one compensation roller, by way of the length of the repositioning path thereof, herein determines the loop length of the surgical suture material. The repositioning path of the compensation roller can in particular be entered at a control unit such that an adjustment of the desired thread length is possible in a simple and precise manner in the case of the device according to the invention.

Because no drawing-off of surgical suture material is performed by way of the front deflection unit, the front deflection unit can preferably be configured as a stationary thread deflection. By contrast, further surgical suture material is drawn off by way of the rear deflection unit as soon as the compensation roller is repositioned from the initial position of the latter. In order for gentle drawing-off of the surgical suture material to be enabled, the rear deflection unit can therefore preferably be configured as a stationary deflection roller.

The deflection installation in one advantageous embodiment can be configured so as to be height-adjustable. Since the cutting-off of the surgical suture material when viewed in the transport direction always takes place behind the deflection installation, the thread advancing gripper must pass the location of the deflection installation in order for the new leading thread end to be transported to the front again. When the deflection installation is configured so as to be height-adjustable the individual components of the deflection installation can yield towards the top or towards the bottom so as to make space for the thread advancing gripper. The thread advancing gripper, on account thereof, can be more rapidly repositioned, in particular on the path to the new leading thread end; moreover, the thread of the surgical suture material is treated with care, on account thereof.

Alternatively or additionally thereto, the thread advancing gripper when moving back without transporting the surgical suture material and/or when moving forward while transporting the surgical suture material, can describe an arc about the deflection installation. The thread advancing gripper could thus bypass the deflection installation so as to be lateral to or above the latter, for example.

In the case of the method according to the invention for cutting-to-length surgical suture material, the surgical suture material by means of a thread advancing gripper is first drawn off from a thread spool having a continuous thread. The thread advancing gripper moves forward to a predetermined terminal position. The surgical suture material by way of a deflection installation is subsequently placed in at least one open loop that runs so as to be angled to the primary transport direction of the drawn-off surgical suture material. On account thereof, further surgical suture material is drawn off from the thread spool without the thread advancing gripper moving any further. The surgical suture material drawn off from the thread spool is subsequently cut off by a cutting unit. The cutting unit herein is positioned between the thread spool and the deflection installation.

The cutting unit is preferably situated close to the deflection installation. On account thereof, the trailing thread end, after the severing of the continuous thread, can drop downwards through the deflection installation and does not completely remain on the deflection installation. This facilitates the onward transport of the cut-to-length thread pieces.

On account of the method according to the invention, the repositioning path of the thread advancing gripper is always identical, independently of the length of the actually cut-off surgical suture material. The repositioning path can be chosen so as to be relatively short so that said repositioning step requires correspondingly little time. While further surgical suture material is drawn off by the deflection installation, the leading thread end is present so as to be already positionally fixed, so that further processing steps can be performed at the leading thread end. The thread advancing gripper can thus move up to a joining location for connecting the surgical suture material to a corresponding needle, for example. In this case, fixing of the leading end of the surgical suture material in the needle can already be performed during the further drawing-off of the surgical suture material. On account of the unwinding of the surgical suture material being performed in parallel with operational processes at the leading positioned thread end, the thread length thus now only has a minimum influence on the actual processing time. Moreover, a longer processing time is available for the actual thread transport by way of the thread advancing gripper on account of the parallel implementation. The surgical suture material can thus be transported more slowly by the thread advancing gripper and thus with greater care for the suture material.

