The present invention refers to a block for- a ^' temporary transport line for the removal e.g. of cut- logs, . and incorporating two pulleys arranged at a distance ^' from ^' each other in a shell,and intended for supporting and/or- forming, an angular deviation of a band, a rope or the like.

Background of the invention

During transport e.g. of timber logs by means of a haulage system (e.g. of the type described in the Swedish patent No. 7808923-2) it often occurs during forest clearing that restrictions of varying kinds and also the ground itself prevents the extention of the transport line along a straight line. Such obstacles can be residual stands, large rocks, meres, lakes etc., which make it necessary to be able to angle the transport line. At long transport distances it may even be necessary to support the rope at regular intervals in order to prevent its hanging from being too great. A problem with existing haulage systems, that work with automatic unloading at predetermined points, is that the carrier and the load strap, in which the load hangs, must be able to be moved past the blocks, without being caught in them or releasing their load.

For similar purposes it has been suggested a block, (American patent No. 2.821.9-37) where on both sides of the block sheave there are arranged support rolls perpendicularly thereto, which will take up the side tension of the rope at the angling, but this arrangement does not guarantee a free ^age of the carrier and load strap through the block, es _t ^ally if the load is not hanging vertically but is drageo ^.long the. ground, as the case is with timber logs. The load strap in this case forms an acute angle with the transport rope .and has a tendency to follow the rope inside the support rolls, with the result that the load will press

2 ■ ^■ • against the block and cause a dead stop. The block there will be connected to the rope, which at its continued" moti will swing the block in the direction of movement. At be the rope jumps out of the block, but if this does not- happe - there will be a complete breakdown of the entire transpo system. When the rope is angled, the block will take up inclined or even a horizontal position, for which the blo is not designed and there is a large risk that the rope c then lose its grip around the rolls and slip off the bloc This known block is furthermore quite useless for transpo ropes of a soft textile band, which has an even great tendency to slide off cylindrical rolls.

Permanent transport arrangements such as ski lifts (Norwegi published patent application 141.550) are equiped with lar rope wheels for supporting the wire and the load. The ro wheels are supported in big yokes with a limited angul adjustability in one plane. These rope wheels in practice c take up almost no lateral angling at all, and can neither used in horizontal position, i.e. with the pivots of the ro ^' wheels positioned vertically, which position the block wi assume as soon as lateral angling occurs.

The purpose of the invention

The purpose of the present invention is to provide a bloc especially for reciprocating transport ropes, which even wh the rope makes a sharp-angled deviation guarantees that t transport line with its carrier and load strap easily c pass through it even when the load is draged along t ground. The block should furthermore be able to work as we when hanging vertically as ^' when inclined or horizonta without the transport rope being thrown off during i reciprocating motion. It should furthermore be insignifica if the rope is pulled in both directions through the block if it moves in one direction only. Another purpose of t invention is to provide a block that can withstand very rou treatment in surroundings where both sand and gravel as we

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3 .—.r as snow and ice formation can occur. These tasks have been

. : ^• -.: SLPlved thereby that the block is designed as a bogie, the

; _E -_. _ .. - _. shell of which is equipped with a suspending member which is

:-. $". ^■*■ ■ ::..-, rotatable at one hand about an axis parallel to the pivots of

^: -..;-- the pulleys, and at the other hand about an axis

•-;-„• perpendicular .to the pivots, whereby the block can assume

.*• . ^* -. ?-required relative positions, when the load approaches, passes

.:-- through and moves away from the block, that the shell and the

. pulleys are formed and arranged substantially to enclose the

.. band with the exception of a slit which is entirely or partly covered by at least one locking device designed to prevent the band from passing through the slit and that the locking device against the action of resetting force can be passed by a strap or the like protruding from the band.

Description of drawings

Fig. 1 shows a perspective view of the block according to the invention adapted as an angling block,

Fig. 2 shows the block according to fig. 1 in a front view.

Fig. 3 is a cross section along line III - III in fig. 2,

Fig. 4 is a modified embodiment of the block according to the invention in a front view.

Fig. 5 shows in enlarged scale a cross section along line V -

V in fig. 4,

Fig. 6 shows a front view of an embodiment of the block shown in fig. 4 and 5;

Fig. 7 is a section along line VII - VII in fig. 6,. and . Fig. 8 and 9 show a fourth embodiment of a block according to ■- _. -,- the invention in side view and front view.

The block according to figs. 1-3 consists of a tube-formed shell 11 of rectangular cross section. Two pulleys 12 are arranged in the shell and in level with the upper part of the pulleys there is arranged a slit 13 extending in the longitudinal direction of the shell and along its entire length. A two-piece lever 15 is rotatably journaled about a shaft 16 just between the the pivots 14 of the two pulleys 12

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k and at the flat side of the shell turned away from the sl

13. The lever 15 is at its upper free end equipped with opening 17 for suspending the block, for example from a tre as shown in fig. 1. The lever 15 consists of two parts 1 and 15b, between which is arranged a journal 18 extending the longitudinal direction of the lever and permitting t shell to rotate relative to the fastening. Because of t rotatable suspension of the shell this can be compared to bogie, which can assume the most suitable position dependi on the pulling forces occuring in the transport rope.

The slit 13 is blocked by. two locking devices 22, which, accordance with fig. 2, each consists of a catch 24 pivotab arranged around an axis 30 and being acted upon by a spri 23.

The block according to the invention works in the followi manner. When a load, e.g. a log, which at one of its ends v a strap and carrier hangs from a transport rope 20 and wi its other end is draged on the ground, approaches one of t blocks, the bogie will pivot in the direction of 'the load, one hand around the shaft 16 and if necessary also around t journal 18, to allow the shell 11 to position itself su stantially in the direction of the rope, i.e. the directi of force, whereby the entry of the carrier 19 into the she is considerably facilitated. The load strap 21 passes throu the slit 13 and thereby swings away the catch 24 against t action of spring 23. When the carrier 19 has passed t suspending lever 15 the bogie will tilt over to the opposi side and assume a position in the direction of the extensi of the load-carrying rope leaving the block, whereby the ex of the carrier from the housing is facilitated. Simu taneously with its tilting movement the bogie can make pivoting motion about the journal 18, which is especial important if the rope has an angular deviation.

At the embodiment according to fig. 4 and 5 the locking device 22 consists of a gear wheel 34 having large teeth, and which is freely rotatable on the same pivot 14 on which the pulley 12 of the block is supported. The diameter of the gear wheel 34 is somewhat bigger than that of the pulley 12, whereas the diameter of the root of the tooth is preferably somewhat smaller than the diameter of the pulley. At least one of the tooth tips is always within a rail 35, which is supported by a yoke 25, fixed to the shell 11 of the block, which in the embodiment shown consists of a rectangular steel tube.

When a carrier 19 fixed on the rope 20 enters the block, a strap 21 which is fixed to the carrier 19 will hit against one tooth of the gear wheel 34, whereby this will rotate enough to let the strap pass through the locking device 22. During the strap's 21 passage through the block at least one of the teeth of the gear wheel 34 will always be in engagement with the rail 35, which means that there at no time during the passage of the strap through the block will be any exposed opening through which the rope 20 can leave the block.

With the embodiment according to fig. 6 and 7 the gear wheel is replaced by a catch 36 pivotable about the pivot 14 and comprising three fingers 26, which by two separate springs 27 are held in such position that the intermediary f-inger when unactuated is in engagement with the rail 35. The springs 27 are with one end each fitted in a groove 28 in the end of the pivot, whereas their opposite ends are provided with a hook 29 each arranged around the edges of the outer fingers 26. A stop 37 is fitted to the catch for limiting the movement of the springs 27. The fingers 26 are so arranged relative to each other, that the strap 21 normally will cooperate only with the intermediary finger whereas the two side fingers during the pivoting motion in either direction temporarily will block the slit between the pulleys 12 and the yoke 25. When the strap has passed the pulley in question the catch 36

will return by spring action to is initial position.

The embodiment according to figs. 8 and 9 differs from t previous in that the locking device 22 consists of a yoke rotatably arranged around a pivot pin 38. The pivot pin 38 supported in attachments arranged at the shell 11 and t yoke 31 encloses the pulley 12 thus that a closed space formed, wherein the rope 20 is placed. The yoke 31 can pivoted in the direction away from the pulley 12 against t action of a spring 32 and the free front end of the yok which is positioned in front of the pulley is provided wi skewed guide flanges 33.

When a strap 21 on the rope 20 shall pass through the blo the strap will push.against the guide flanges of the yoke and press the yoke in a direction away from the pulley 12 that the strap can pass. Since the block is equipped with t pulleys with associated locking devices and the strap on actuates one pulley at a time there is always one locki device ready to prevent the line from leaving the block.

The invention is not limited to the embodiments shown a described but a number of variations are possible within t scope of the claims. Thus the shell need not be tube-forme but could have another shape, but what is important is th the pulleys 12 of the block are positioned at such a distan from each other and from the shaft 16 of the suspending ^" lev

15 that the bogie can make pivoting movements relative to t lever 15. It is also important that the load strap 21 given possibility to pass through the block witho obstructions, which has here been achieved with the aid the slit 13, that need not necessarily be a slit in a tu but can instead be other limiting means e.g. a guide rail. is also important in this connection that the rope cann leave the shell even if the block should assume a horizont position, which is the case if the angular deviation relatively sharp. With the block according to the inventi o angles of 0-180 can be mastered.