APPARATUS FOR PREPARING LENGTH SYMBOLS ON PRODUCTS OF HIGH LENGTH/DIAMETER RATIO, ESPECIALLY ON CABLE MANTLES

Abstract: The apparatus for preparing length symbols on products of high length/diameter ratio, especially on cable mantles includes at least one signing unit arranged in transporting means having drive (4, 5) for conveying a product of high length/diameter ratio, especially cable, wherein the signing unit has a contacting surface bearing a negative pattern of the symbols to be prepared on the surface of the product, the contacting surface being connected with respective outputs of at least one container for forwarding a paint substance to the negative pattern. According to the invention the apparatus is equipped with at least two detecting elements (1, 2) associated with a section of predetermined length of the product and on the contacting surface of the signing unit the negative pattern includes a part for preparing a length symbol (6) which is recognisable by the detecting elements (1, 2) and further the detecting elements (1, 2) are connected with positioning means (3) applied for controlling a system of regulating the drive (4, 5) of the signing unit.

Description: APPARATUS FOR PREPARING LENGTH SYMBOLS ON PRODUCTS OF HIGH LENGTH/DIAMETER RATIO, ESPECIALLY ON CABLE MANTLES FIELD OF THE INVENTION The invention refers to an apparatus for preparing length symbols on products of high length/diameter ratio, especially on cable mantles made of an appropriate plastic material. The proposed apparatus is equipped with drum type means for conveying a product of high length/diameter ratio, especially a cable, wherein the conveying means are prepared with a signing unit having a contacting surface bearing a negative pattern of the symbols to be brought onto the surface of the product, especially on the cable mantle, and the contacting surface is connected with respective output of at least one container for forwarding a paint substance to the negative pattern prepared on the contacting surface. The apparatus of the invention is capable of preparing length symbols at predetermined distances with high precision of their location on different products including cables, tubes, especially plastic tubes and bands. BACKGROUND OF THE INVENTION The cable mantles and many other products of high length/diameter ratio manufactured in a continuous manner are usually made of plastics and especially of polyethylene or polyvinyl-chloride. These products usually and the cable mantles always are prepared with symbols referring to the kind of the application of the product and with length symbols prepared at predetermined distances. In the case of cables the length symbols are consisted of a set of numbers determining the length in an appropriate unit and of course further symbols can be used also. Different apparatuses for preparing length and other symbols on the cable mantles are known from the German patent specifications No DE-C3 23,57,494 and DE-C3 25,09.027. The specifications of the patents mentioned show a solution according to which the product (cable) is conducted between signing drums and the symbols are prepared with a paint substance which is bond rather by chemical forces then by adhesion with the material of the mantle. This is carried out in the way that a pulverised paint substance is brought to a negative pattern prepared on the surface of the drum contacting ther product during conveying the product in the manufacturing line. The paint substance is forwarded onto the surface of the cable by applying an appropriate pressure between the product and the contacting surface and it is fixed by applying elevated temperature. The pattern printed in this way in the surface of the mantle is very stable and can be expelled only by a very intensive wearing action. The basic SUBSTITUTE SHEET problem of the known apparatuses is that the precision of the pattern and length symbols is low because the change of the temperature, the slip of the cable, the vibration movement of the different heavy units in the environment of the drums cause inevitable inequalities in the speed of forwarding the cable. Different means can be applied to diminish the effects mentioned, however it is practically impossible to avoid slip and vibration. Hence, the known method of controllig the accuracy of the length symbols prepared is to stop the " process of manufacturing the cable, to cut out a section of the cable and thereafter to compare the length of the section cut out with that of a master section and finally to carry out trials for adjusting the apparatus in order to change and ensure the distance between the length symbols according to the required value. It is, however, not desired to stop the manufacturing process, this stop can disturb the work of other cooperating machines and apparatuses and further it is inadvantageous with regard to the economy of the production. It is to be stated, however, that neither in the manufacturing process nor in the application of cables of usual traditional destinations the inaccuracy of the length symbols can cause specific problems because these products are relatively inexpensive and the distance of the length symbols van vary in wide ranges without involving any difficulties in application - the knowledge of the accurate length of a cable section is not especially important. On the contrary, the cables applied in the modern telecommunication and data forwarding systems and other similar products should meet very high quality requirements, their length has to be known with high accuracy when laying them down, sometimes in the sea and mountains. Hence, it is very important to carry out the length symbols with high precision. The cables of this kind are very expensive, the quality requirements are also very high. This is the basis why a need is felt to create an apparatus which allows to prepare the length symbols on the products of high length/diameter ratio with high precision without stopping and breaking the manufacturing process. The aim of the invention is to offer a solution for this need SUMMARY OF THE INVENTION The invention is based on the recognition that the basic problem of the known apparatuses for preparing the length symbols is that they are characterized with very low elasticity of the control system. Hence, it is necessary to equip them with an adaptive control system based on optoelectronic elements which is capable of recognising the length symbols prepared and of realising a feed-back in the system of preparing the length symbols. __ Thus, the invention should offer an apparatus whereby the high precision of the distances between the length symbols on products of high L/D (length/diameter) ratio, especially cable mantles can be ensured also when the technological conditions quickly or often change, sometimes in unexpected manner. The object of the invention is therefor an apparatus for preparing length symbols on products of high length/diameter ratio, especially on cable mantles, including at least one signing unit arranged in transporting means having drive for conveying a product of high length/diameter ratio, especially cable, wherein the signing unit has a contacting surface bearing a negative pattern of the symbols to be prepared on the surface of the product, the contacting surface being connected with respective outputs of at least one container for forwarding a paint substance to the negative pattern. The essence of the invention is the the proposed apparatus is equipped with at least two detecting elements associated with a section of predetermined length of the product and on the contacting surface of the signing unit the negative pattern includes a part for preparing a length symbol which is recognisable by the detecting elements and further the detecting elements are connected with positioning means applied for controlling a system of regulating the drive of the signing unit. It is especially advantageous and gives an evidence of production when the apparatus according to the invention is made with positioning means equipped with a device for generating signal for determining the length of the product. The use of the apparatus of the invention is facilitated and the accuracy of the control can be improved in the advantageous embodiment wherein the positioning means are capable of regulating the rotating speed of motors applied in the drive of the signing drums. The apparatus of the invention can be especially simple when the signing unit includes at least one drum pressed by the contacting surface to the product and the drive is linked with the the at least one drum. The apparatus of the invention can be used for preparing length symbols of very high precision on products manufactured in technologic conditions showing quick changes wherein the equal distance of the length symbols can be always ensured. The error of this distance is usually very small. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further described by way of example with reference to some preferred embodiments wherein reference is made to the accompanying drawings. In the drawings Fϊg. 1 is the block scheme of the apparatus of the invention. DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS According to the invention an apparatus is prepared for bringing length symbols onto the surface of different products of high length/diameter ratio, especially cable mantles and this apparatus consists of elements depicted in Fig. 1. The proposed apparatus should be. applied together with the usual apparatuses for producing cables and other endless products, e.g. plastic bands and it can be connected with such apparatuses, e.g. with that shown in the German patent specification No DE-C323,57 r 494. In the apparatuses for bringing length symbols onto products of high length/diameter ratio the use of a signing unit comprising two signing drums is the common practice. The signing drums are made with a contacting surface pressed to the product and having a negative pattern in form of concavations corresponding to the shape of the signs to be prepared on the surface of the product. The use of a negative pattern wherefrom an appropriate paint substance gives the positive pattern on the surface of the product is a common practice, too. The concavations are usually filled up with a pulverised paint substance fed from an appropriate separate container and this paint substance forms a melt when it is brought onto the surface of the product- The molten paint material adheres to the surface and gives a stable positive pattern. The advantageous and important features of the apparatus of the invention is that the negative pattern ont the contacting surface of the signing drums is equipped always with an auxiliary sign arranged between the other usual signs and this auxiliary sign is associated with a distance to be signed. In good conditions the signs are prepared also equidistantly. hence, they can be applied as the basis of determining of the length of the product. In the proposed apparatus after the signing drums, in the way of forwarding the product two detecting elements 1 and 2 are arranged and the distance between these detecting elements 1 and 2 corresponds exactly to the length to be signed on the surface of the product. The detecting elements 1 ^ and 2 are prepared for recognising symbols 6 prepared on the surface of the product and they are connected to a usual device for pattern recognition. It is especially preferred to prepare the symbols 6 in the form of a lying T letter because this pattern is very easy to recognise. The detecting elements 1 and 2 are connected with positioning means 3 capable of regulating the speed of rotation of the signing drums through drives 4 and 5 containing motors 7 and 8. The positioning means 3 preferably are prepared as a part of a computer system of regulation and the computer system is that which receives and processes the signals of the positioning means and by processing the signals it is capable of determining and evidencing the length of the prepared product. The computer system is also capable of taking over the regulation of the drives 4 and 5, in given case motors 7 and 8 or to influence the. system of regulation. The apparatus of the invention works in the following way: The signing drums prepare the length symbols and other required symbols on the surface of a product of high length/diameter ratio being forwarded by and between them. The signing drums receive in concavations of their contacting surfaces a pulverised paint substance to be brought onto the surface of the product. Among the different symbols it is one symbol 6 which is generally a lying letter T, comprising a vertical line being easily recognisable by the detecting means 1 and 2. During conveying the product the detecting means 1 and 2 recognise this vertical line or other length symbol 6 and generate an appropriate electric signal. If the product is conveyed so that two length symbols 6 arrive in the same time to the field of sensing of the detecting means 1 and 2 the positioning means 3 have to carry out no regulation. On the contrary, if the length symbols 6 come at different time points to the field of sensing of the detecting means 1 and 2, the electric signals generated by the last arrive in different moments to the positioning means. The absolute value and the sign of the time difference between the electric signals generated are the basis of carrying out a regulation step for influencing the drives 4 and 5 and/or the motors 7 and 8 according to the known principles of the regulation technics. This regulation makes the product be conveyed slower or quicker in dependency on the sign of the time difference. In this way the proposed apparatus takes into account all changes in the technologic conditions and it is not intended to influence the other units applied in the technologic line. If the drives 4 or 5 and/or the motors 7 or 8 cannot be regulated for diminishing the length error to zero or an acceptable minimum, the positioning means 3 can generate a signal watching the staff of the technologic line that other units of this line should be also regulated. By the means of the apparatus of the invention it is possible to prepare length symbol with high precision of their distance, the distance is equal with the basic distance selected, and the error remains under ± 3 %, i.e. the length of a prepared section can be determined with high precision.

Claims: CLAIMS: 1. Apparatus for preparing length symbols on products of high length/diameter ratio, especially on cable mantles, including at least one signing unit arranged in transporting means having drive (4, 5) for conveying a product of high length/diameter ratio, especially cable, wherein the signing unit has a contacting surface bearing a negative pattern of the symbols to be prepared on the surface of the product, the contacting surface being connected with a respective output of at least one container for forwarding a paint substance to the negative pattern, characterised in that it is equipped with at least two detecting elements (1, 2) associated with a section of predetermined length of the product and on the contacting surface of the signing unit the negative pattern includes a part for preparing a length symbol (6) which is recognisable by the detecting elements (1, 2) and further the detecting elements (1, 2) are connected with positioning means (3) applied for controlling a system of regulating the drive (4, 5) of the signing unit. 2. Apparatus according to claim 1, characterised in that the positioning means - (3) are equipped with a device for generating signal for determining the length of the product. 3. Apparatus according to claim 1 or 2, characterised in that the positioning means- (3) are capable of regulating the rotating speed of motors (7, 8) applied in the drive (4, 5) of the signing drums- 4. Apparatus according to any one of claims 1 to 3, characterised in that the signing unit includes at least one drum pressed by the contacting surface to the product and the drive (4, 5) is linked with the drums.

Inventors: GYETVAI LASZLO, KESZLER GABOR, LACZKO MIHALY, PALOTAS MIHALY, RITECZ JOZSEF, GYETVAI, LASZLO, KESZLER, GABOR, LACZKO, MIHALY, PALOTAS, MIHALY, RITECZ, JOZSEF
Applicants: GYETVAI LASZLO, KESZLER GABOR, LACZKO MIHALY, MKM MAGYAR KABEL MU & CIR & VE, PALOTAS MIHALY, RITECZ JOZSEF, MKM MAGYAR KABEL MUEVEK
Application year: 1993
Main classification: H01B7
IPC codes: B41F17