NO120105B

NO120105B -

Info

Publication number: NO120105B
Application number: NO16091865A
Authority: NO
Inventors: S Koll; J Rocus
Original assignee: American Flange & Mfg
Priority date: 1964-12-24
Filing date: 1965-12-15
Publication date: 1970-08-24
Also published as: FI46944B; NL154986B; AT291808B; BE673553A; FI46944C; CH429483A; DK122652B; NL6516846A; GB1079120A; SE302896B; ES321119A1; DE1482607A1; MY6900135A

Description

Avlastningsklemme for gjennomgående elektriske luftledninger. Relief clamp for continuous electrical overhead lines.

Oppfinnelsen angår en avlastningsklemme for gjennomgående luftledninger, The invention relates to a relief clamp for continuous air lines,

hvor ledningen bøyes og på den ene side where the wire is bent and on one side

som vender fra trekksiden er innklemt which faces from the pull side is pinched

mellom to klemmelegemer, hvorav minst between two clamping bodies, of which at least

ett er kileformet, og som bare er forskyvbare i forhold til klemmekappen. one is wedge-shaped, and which can only be moved in relation to the clamp cover.

Det er kjent slike klemmer hvor imid-lertid klemmelegemene ikke gir den ønske-de understøttelse av ledningen i bøyeom-rådene, slik at ledningen i disse områder utsettes for unødvendig store påkjenninger. Such clamps are known where, however, the clamping bodies do not provide the desired support for the wire in the bending areas, so that the wire in these areas is exposed to unnecessarily large stresses.

Hensikten med oppfinnelsen er å unn-gå disse påkjenninger mest mulig, og det The purpose of the invention is to avoid these stresses as much as possible, and that

oppnås ifølge oppfinnelsen ved at det på is achieved according to the invention in that on

innsiden av bøyen beliggende klemmelegeme, som strekker seg over klemmens hele clamping body located inside the bend, which extends over the whole of the clamp

lengde, i området av ledningsutløpet og retningsendringen har mindre bøyemotstand length, in the area of the wire outlet and the change of direction has less bending resistance

enn på klemmestedet, dvs. i motkilens område. than at the clamping point, i.e. in the area of the counter wedge.

De flater av klemmelegemene som ligger an mot ledningen har vanligvis en The surfaces of the clamping bodies which abut against the wire usually have a

krumningsradius som tilsvarer krumningsradien for tverrsnittet av ledningen. Det radius of curvature which corresponds to the radius of curvature of the cross-section of the wire. The

har vist seg at ved innklemning av en ledning i to slike klemlegemer, virker de ytre it has been shown that when a wire is clamped in two such clamping bodies, they act externally

trådlag som et rør slik at disse opptar den wire layers like a tube so that these occupy it

største del av klemtrykket, uten at de indre most of the clamping pressure, without the internal

trådlag får en tilsvarende andel av klem-metrykket. Derved blir de ytre trådlag ster-kere belastet for trekk enn de indre trådlag. wire layers receive a corresponding share of the clamping pressure. Thereby, the outer thread layers are more heavily strained than the inner thread layers.

For å overvinne denne ulempe har To overcome this disadvantage has

krumningsradien for klemlegemenes anleggsflate for ledningen ifølge en videre ut-førelse en større krumningsradius enn the radius of curvature for the contact surface of the clamping bodies for the cable according to a further embodiment a larger radius of curvature than

tverrsnittet av den ikke klemte ledning. Ved innklemning mellom slike klemmelegemer får ledningstverrsnittet en oval form som ikke lenger har den fryktede, røraktige virkning, slik at de indre trådlag også blir klemt inn i ønsket grad og derved opptar den andel av ledningstrekket som tilkommer disse. the cross-section of the unclamped wire. When sandwiched between such clamping bodies, the wire cross-section takes on an oval shape which no longer has the dreaded, tube-like effect, so that the inner wire layers are also squeezed in to the desired degree and thereby take up the proportion of the wire length that belongs to them.

Det er tilstrekkelig når en av de to klemmelegemer har en kilevinkel. Det andre klemmelegeme kan da være utformet uten kilevinkel, slik at det glir lettere i klemmetappen. En innbyrdes forskyvning av de to klemmelegemer gjøres umulig ved den allerede nevnte bøyleskrue. Særlig hen-siktsmessig har det vist seg for en klemme ifølge oppfinnelsen, når et av de to klemmelegemer består av en kjegle resp. en konushalvdel med svært liten kilevinkel i størrelsesorden av ca. 1 : 100, idet det andre klemmelegeme da har den vanlige eller noe større kile-vinkel. It is sufficient when one of the two clamping bodies has a wedge angle. The second clamping body can then be designed without a wedge angle, so that it slides more easily in the clamping pin. A mutual displacement of the two clamping bodies is made impossible by the already mentioned hoop screw. It has proved particularly expedient for a clamp according to the invention, when one of the two clamping bodies consists of a cone or a cone half with a very small wedge angle of the order of approx. 1:100, as the second clamping body then has the usual or somewhat larger wedge angle.

Oppfinnelsen anvendes fortrinnsvis ved avlastningsklemmer, hvor ledningen bibringes en retningsendring mellom sitt innløpssted i klemmekappen og klemmestedet. Derved kan det ene klemmelegeme være forlenget utover innløpsstedet for ledningen, slik at ledningen i bøyningsområdet ligger på dette. Da dette klemmelegeme forskyver seg noe i klemmekappen ved inn-spenningen, består den fare at den i bøy-ningsområdet deformeres på ufordelaktig måte og at den i enkelte tilfelle kan briste. For å hindre dette blir deler av dette klemmelegeme utført med forskjellig bøyemot-stand på sådan måte at det ved innløps-stedet og i området for bøyningen av led- The invention is preferably used for relief clamps, where the cable is given a change of direction between its entry point in the clamp cover and the clamp point. Thereby, one clamping body can be extended beyond the entry point for the cable, so that the cable in the bending area lies on it. As this clamping body displaces somewhat in the clamping sleeve during tightening, there is a risk that it is deformed in an unfavorable manner in the bending area and that it may break in some cases. To prevent this, parts of this clamping body are made with different bending resistance in such a way that at the inlet point and in the area for the bending of the

Claims

ning has less hardness than at the clamping point and that it has a smaller cross-section at the inlet point.

An embodiment of the invention will be explained in more detail with reference to the drawing.

Fig. 1 shows an elevation of a clamp according to the invention.

Fig. 2 shows a side view of the clamp in fig. 1 seen against the direction of arrow II.

The clamp cover 1 is made in the form of a hoop, as can be seen from fig.

2. A bolt 2 is inserted through the two hoops and secured with a cotter pin 3. 4 is a washer. In the bolt 2, a tension member, not shown, engages. The hoop-shaped clamp jacket is designed in such a way that the incoming wire in the area la gets a change of direction (bend) before it enters the clamp area lb, where it is enclosed by the two clamp bodies 5. The clamp body 5 is a wedge with a fairly large wedge angle , which is supported in the open hoop-shaped clamping casing against two internal side strips on which it can slide. When the clamping body 5 and the bolt 2 are removed, the hoop-shaped sheath is completely open so that the cable can be inserted without difficulty. The clamping body 6 has no or only a small wedge angle in the order of 1:100. It is previously extended so far that it protrudes with its end 6a from the clamping sleeve 1. Its rear end 6b likewise protrudes from the clamping sleeve and carries a pressure plate 7 for the bending screw 8. The pressure plate is attached to the clamping body 6 by means of rivets 7a or in a similar way. The bending screw 8 penetrates through projections 5a on the side of the clamping body 5, so that when the nuts 10 are tightened, the wire 9 is clamped between the rear ends 6b and 5b of the clamping bodies 6 and 5. The two clamping bodies 6 and 5 are thereby secured against mutual displacement in the direction of the wiring.

The clamping bodies 5 and 6 have a domed contact surface 5c or 6c. While the radius of curvature of these domed contact surfaces has up to now corresponded to the radius of the unclamped wire, the contact surfaces 5c, 6c have the radius of curvature r which is greater than the radius of curvature of the unclamped wire. the wedge-shaped clamping body 5 pushed into the sheath is oval in shape, so that the above-described better clamping of the inner wire layers is achieved. This clamping is so good that the clamping and friction obtained by means of the hoop screw 8 are kept within relatively small values. As a result, the clamping bodies are in this case

lie straight in the direction of the wire 9, so that the wire can also run through without deformation in the area of the extra clamp formed by the hoop screw 8. The projections 5a and the wedge are so strong that they provide a storage for the hoop screw 8. As a result, a displacement of the clamping piece 6 in relation to the clamping piece 5 is excluded in the direction of the wiring. When the clamping pieces 5, 6 are retracted into the sheath by tensioning the wire 9, the clamping pieces 5 and 6 move together slightly forwards. Hereby, the front curved end 6a in the area 1a of the clamp cover would rise somewhat above this if it was not pressed against the bottom of the cover under the effect of the cable stretch in the direction of the arrow 11. This naturally bends. In order for this bending to take place without disadvantages due to the firmness, the front end 6a, especially in the area of the bending la in the clamping cap 1, is made softer than the other parts of the clamping body 6, especially the part that lies in the area of the wedge clamp -means effect.

Patent claims: 1. Relief clamp for continuous electric overhead cables, where the cable is bent and on the side facing from the pulling side is clamped between two clamping bodies, at least one of which is wedge-shaped, and which are only displaceable together in relation to the clamping cap, characterized in that on the inside the clamping body (6) located away from the bend, which extends over the entire length of the clamp, in the area of the cable outlet and the change of direction has less bending resistance than at the clamping point, i.e. in the area of the counter wedge (5). 2. Relief clamp according to claim 1, characterized in that the clamping body (6) located on the inside of the bend has no wedge angle or only a very small wedge angle of the order of 1:100.

3. Relief clamp according to claim 1 or 2, characterized in that the rear end of the clamping body (6) located on the inside of the bend which cooperates with the other clamping body (5) consists of hard material, while the front end consists of soft material.

4. Relief clamp according to claims 1-3, characterized in that the two clamp body ends (5b, 6b) protruding from the clamp cover (1) are pressed against the wire by means of a hoop screw (8) or the like, which prevents their mutual displacement in the longitudinal direction.

Cited publications:

Swiss Patent No. 272,393.

German Patent No. 589,193, 644,847.