Arrangement for handling cylindrical bodies provided with central holes

Abstract: The invention relates to an arrangement for handling cylindrical bodies (1) provided with central holes, the apparatus comprising gripping arms (2) provided with gripping pins (3), second means (4) arranged to move the gripping arms (2) to obtain a forward movement (PL), third means (7) arranged to wind the gripping arms (2) clockwise and counterclockwise, and fourth means arranged to move the gripping arms (2) towards each other such that the gripping pins (3) are self-centeringly brought into alignment with the central holes of the cylindrical body (1) and to make a reverse movement of release. To provide an arrangement operating with high speed, the second means (4) by which the forward movement (PL) of the gripping arms (2) is obtained and/or the third means (7) by which the winding movement of the gripping arms (2) is obtained are formed as an elastic structure in a predetermined area such that the gripping arms (4) are capable of adapting, during the grip movement and movement of release, to the displacements of position within this area, the displacements being determined by the position of the body (1) or the position of the stand carrying the body (1).

Description: The invention relates to an arrangement for handling cylindrical bodies provided with central holes, the apparatus comprising gripping arms provided with gripping pins, first means arranged to move the gripping arms in the horizontal and vertical direction, second means arranged to move the gripping arms to obtain a forward movement, third means arranged to wind the gripping arms clockwise and counterclockwise, and fourth means arranged to make a grip movement by moving the gripping arms towards each other such that the gripping pins are self-centeringly brought into alignment with the central holes of the cylindrical body and to make a reverse movement of release in which the gripping pins are disengaged from the central holes of the cylindrical body. Today the above arrangements are known in various fields of technology. For example, arrangements of this kind are used in fields associated with cables, i.e. in the manufacture and use of cables, the users being the companies and communities manufacturing and using cables. Arrangements used in the handling of cable reels are described e.g. in U.S. Patent 3,822,044, PCT Patent Application WO 82/02187. Such arrangements are used, for example, for taking cable reels to reel positions in a storage of cables and, correspondingly, for fetching cable reels from reel positions. When a cable reel is fetched, the gripping arms of the arrangement are moved e.g. in a desired manner in the horizontal and/or vertical direction, a forward movement is made by moving the gripping arms forward to the cable reel in the reel position, and finally a grip movement is made by moving the gripping arms towards each other such that the gripping pins grip into the holes of the reel hub. Further, the gripping arms can be wound clockwise or counterclockwise, if necessary. When a cable reel is taken to a reel position, the principles of operation are the same but the steps are carried out in a reverse order. The problem with the known solutions it to achieve sufficient accuracy. In practice it is rather difficult to bring the gripping pins sufficiently accurately into alignment with the holes of the reel hub in the gripping step and on the other hand it is difficult to achieve accurate release of the reel in the releasing step. These matters gain in significance if the measuring tolerances of the reel position and/or of the reel itself are high. On account of this, gripping arms are guided accurately in the horizontal and vertical directions etc. in the known solutions by using, in addition to the measured location data on the reel position, a separate location sensor and a counterpart of the sensor, e.g. a reflector, fastened to each reel position. However, displacements other than the above horizontal and vertical displacements, i.e. displacements in the direction of the forward movement and in the winding direction, remain problematic. To make the movements accurate, several correcting movements are needed, which in turn slows down the operation. Another drawback of the prior art is the high level of costs, for the tolerances required have been very low since the requirements for accuracy have been high. The object of the invention is to provide an arrangement by means of which the drawbacks of the known art can be eliminated. This has been achieved by the arrangement of the invention, which is characterised in that the second means by which the forward movement of the gripping arms is obtained and/or the third means by which the winding movement of the gripping arms is obtained are formed as an elastic structure in a predetermined area such that the gripping arms are capable of adapting, during the grip movement and movement of release, to the displacements of position within this area, the displacements being determined by the position of the cylindrical body or the position of the stand carrying the cylindrical body. An advantage of the arrangement according to the invention is above all that the gripping pins can be made to grip into the central holes of the cylindrical body without any time-consuming correcting movements. On account of the above the structure of the arrangement is simplified in regard to the previously known solutions and the costs decrease since the tolerances may be higher than before. Another advantage of the arrangement of the invention is the speed of operation, which is substantial particularly in connection with large storages of reels. A further advantage is the simplicity of the arrangement, whereby the production and servicing costs are not so high. In the following the invention will be described by means of an advantageous embodiment presented in the drawing, wherein Fig. 1 shows a principle side view of an embodiment of the invention, and Fig. 2 shows a view of the embodiment of Fig. 1 in the direction of the arrows II-II. Figs. 1 and 2 show, in principle, an embodiment of the invention. The reference number 1 indicates a basically cylindrical body, such as a reel, which may be e.g. a cable reel. The number 2 indicates gripping arms in which are arranged gripping pins 3 for gripping the central hole of the reel 1. The arrangement comprises first means, which are arranged to move the gripping arms 2 in the horizontal and vertical direction. Said first means are not shown in the figures. They may be any solutions known per se , including e.g. rails, rollers, pillars and hydraulic cylinders. Second means, which are arranged to move the gripping arms 2 to obtain a forward movement, are indicated generally in the figures by the number 4. The direction of the forward movement is indicated in Fig. 1 by the arrow PL. Here the forward movement means the movement of the gripping arms made e.g. after the first means have moved the gripping arms to a reel position, i.e. the movement by which the gripping arms are moved to a reel in a reel position in a gripping situation. Naturally, a corresponding movement is also made when a reel is released. The second means 4 may comprise e.g. a hydraulic cylinder 5 and a ball bushing 6. Third means, which are arranged to wind the gripping arms 2 as a single whole clockwise or counter-clockwise, are indicated generally in the figures by the number 7. The winding movement is indicated in Fig. 2 by the arrow KL. The third means 7 may comprise e.g. a spiral wheel structure. The arrangement further comprises fourth means, which are arranged to make a grip movement by moving the gripping arms 2 towards each other such that the gripping pins 3 are self-centeringly brought into alignment with the central holes of the reel 1 and, in addition, a reverse movement of release in which the gripping pins 3 are disengaged from the holes of the reel 1. The grip movement and movement of release are indicated in Fig. 2 by the arrows TL. Said fourth means are not shown in the figures. They may be any means known in the field, such as hydraulic cylinders, tooth wheels, tooth racks, or other corresponding means. The gripping pins 3 are preferably cone-shaped, whereby they operate self-centeringly. The essential feature of the invention is that the second means 4 by which the forward movement of the gripping arms 2 is obtained and/or the third means 7 by which the winding movement of the gripping arms 2 is obtained are formed as an elastic structure in a predetermined area such that the gripping arms 2 are capable of adapting, during the grip movement and movement of release, to the displacements of position within this area, the displacements being determined by the position of the reel 1 or the position of the stand carrying the reel. By elasticity is meant that the structure comprising e.g. the gripping arms 2, i.e. the grab, is formed as a self-centering structure elastic within a certain area. By using a structure of e.g. spring members 8 in connection with the second means 4 by which the forward movement is obtained, a floating movement is obtained in a certain area, whereby the gripping arms 2 can be brought to a position according to the reel 1 in the direction of the forward movement in the gripping step. In the reel release step, i.e. when a reel is brought to and left in a reel position, centering of the elastic area centers the reel 1 to a position desired but allows transfer in a certain area to a possibly unusual position determined by the stand carrying the reel, such as the reel cradle. On account of the above floating or adaptive structure, the position of the gripping arms need not be determined with absolute precision but the arrangement operates with higher location tolerances than before. The operation of the above structure is clearly seen from Fig. 1, which shows that the piston rod of the hydraulic cylinder 5 is supported by the spring members 8 against the unit comprising the gripping arms 2, whereby the above floating structure is formed. In connection with the third means by which the winding movement of the gripping arms is obtained a corresponding elastic structure can be provided by spring members 9. As shown in Fig. 2, the spiral wheel axle of the above third means 7 is supported, at one end thereof, by the spring members 9 against the unit carrying the gripping arms 2, whereby a floating structure is formed that is similar to that described above in connection with the second means 4 by which the forward movement is obtained. On account of the above structure, the arrangement according to the invention is also elastic in the winding direction KL, whereby the position need not be determined time-consumingly with absolute precision. Any suitable spring members can be employed as the spring members 8, 9. For example, metal springs or other mechanical springs that are simple and do not require servicing can be used. The above embodiment is not in any way intended to restrict the invention but the invention may be modified quite freely within the scope of the claims. Thus it is clear that the arrangement of the invention or the details thereof need not necessarily be exactly the same as shown in the figures but other kinds of solution are also possible. It is clear that e.g. the structure of the gripping arms need not be exactly the same as shown in the figures but that the gripping arms may also be different. In fact, the term in question should be understood to mean means in general for gripping a cylindrical body. Further, the manner of controlling the arrangement is not restricted in any way but the arrangement may be a part in a complex robot or a part in an apparatus moving along a simple rail. The spring members need not be metal springs but e.g. rubber springs or springs of plastic material can be used. The only essential feature is that elasticity is not brought about by the operating pressure of e.g. the hydraulic cylinder 5 or some other corresponding hydraulic cylinder but by a member operating independently. In addition, the spring members need not necessarily be located at the exact positions shown in the figures but other positions are possible also, e.g. the attachment point of the hydraulic or pneumatic cylinder, the piston or some other part of the cylinder. Furthermore, the invention is not in any way restricted to be used only with cable reels but it can also be used in handling other corresponding cylindrical bodies provided with central holes. The features disclosed in the foregoing description, in the following claims and/or in the accompanying drawings may, both separately and in any combination thereof, be material for realising the invention in diverse forms thereof.

Claims: An arrangement for handling cylindrical bodies (1) provided with central holes, the apparatus comprising gripping arms (2) provided with gripping pins (3), first means arranged to move the gripping arms (2) in the horizontal and vertical direction, second means (4) arranged to move the gripping arms (2) to obtain a forward movement (PL), third means (7) arranged to wind the gripping arms (2) clockwise and counterclockwise (KL), and fourth means arranged to make a grip movement by moving the gripping arms (2) towards each other such that the gripping pins (3) are self-centeringly brought into alignment with the central holes of the cylindrical body (1) and to make a reverse movement of release in which the gripping pins (3) are disengaged from the central holes of the cylindrical body, characterised in that the second means (4) by which the forward movement (PL) of the gripping arms (2) is obtained and/or the third means (7) by which the winding movement (KL) of the gripping arms (2) is obtained are formed as an elastic structure in a predetermined area such that the gripping arms (4) are capable of adapting, during the grip movement and movement of release, to the displacements of position within this area, the displacements being determined by the position of the cylindrical body (1) or the position of the stand carrying the cylindrical body. An arrangement according to claim 1, characterised in that the elastic structure is provided by spring members (8,9) arranged in the second and/or third means (4,7). An arrangement according to claim 2, characterised in that the spring members (8,9) are mechanical springs.

Inventors: HEINO MARKKU, PARRI MAURI, HEINO, MARKKU, PARRI, MAURI
Applicants: MAILLEFER NOKIA HOLDING, NOKIA-MAILLEFER HOLDING S.A.
Application year: 1992
Main classification: B65H67
IPC codes: B25J15, B65H67, B65G7