DEVICE FOR VEHICULAR CRANES

Abstract: The invention relates to a device for vehicular cranes (1) of the type that includes a jib (3) which is movable in relation to a vehicle and has a grab tool (6). A rope reel (9) is mounted on the crane jib (3) which, in a way known per se, is loaded by a spring which always strives to wind up a rope (10) on the reel and against the action of which a free part of the rope may be manually pulled out from the reel. The reel co-operates with a dolly (11) accompanying the crane jib, which dolly is distanced from the reel and by means of which the rope may be locked in a given point in order to enable the hauling in of an object (7) coupled to a free end of the rope by turning or displacing the crane jib (3).

Description: DEVICE FOR VEHICULAR CRANES Technical Field of the Invention This invention relates to a device for vehicular cranes of the type that comprises a jib which is movable in relation to the appurtenant vehicle and on which a rope reel is mounted, said reel being, in a known way, loaded by a spring which always strives to wind up a rope on the reel and against the action of which a free part of the rope may manually be pulled out from the reel. Background of the Invention Cranes of the kind generally mentioned above are used, among other things, on forwarders and similar vehicles which have the purpose of collecting logs laying in the forest after the felling, deli bing and crosscutting of growing trees, and then transporting the logs to a road which may be frequented by main road vehicles. When the ground conditions are benign and the crane has a large range of action, problems do not usually arise to reach the logs with the grab tool of the crane. However, in the cases when the terrain is rough, it happens that individual logs cannot be reached by the grab tool. The conditions for the log to be reached are, of course, impaired if the crane at the same time has a limited range of action. In order to enable loading of the individual log on the load carrier of the vehicle, it is, in such cases, required that the log is carried on to the area of the range of action of the crane in another way than by means of the actual crane. Previously, this has, among other things, been carried out by means of motor-driven winches from which a rope, wire, chain or the like may be led out and then hoisted in. However, winches of this type require a comparatively strong motor, which entails that the winch in its entirety becomes expen- sive, not only to manufacture, but also to mount and use. By SE 8002347-6, a draying device is previously known having a spring-loaded reel from which a rope may be pulled out and coupled to logs. In this case, however, a locking device for locking the rope is arranged to block the reel. This is some- thing which makes the handling of the device more difficult as well as complicates the construction. Objects and Features of the Invention The present invention aims at obviating the above- mentioned disadvantages of previously known techniques and at providing a simple and inexpensive device for the above-mentioned purpose. Thus, a primary object of the invention is to provide a structurally simple mechanical device by means of a few, simple and inexpensive components at the same time -as the device should be able to be mounted on various embodiments of such cranes which comprise grab tools. According to the invention, at least the primary object is attained by the features defined in the characterizing clause of claim 1. A preferred embodiment of the invention is furthermore defined in the dependent claim. Brief description of the appended drawings In the drawings fig 1 is a partial, schematic side view of a vehicular crane having a grab tool and a device according to the invention, fig 2 is an enlarged, schematic view of the device according to the invention in connection with the hauling in of a log, fig 3 is an analogous view showing the device in an inactive state, fig 4 is a view from below of the outer end portion of a crane jib shown in fig 1, and fig 5 is a perspective view of a dolly mountable on the crane jib. Detailed Description of a Preferred Embodiment of the Invention In fig 1, a crane - in its entirety designated 1 - is shown which, in a conventional way, includes a main jib 2 and a jib lever 3. This jib lever 3 may advantageously include one or more telescopic tubes 4 by means of which the jib may be extended and shortened. A rotator 5 is applied to a free end of the outermost telescopic tube 4, which rotator in turn carries a grab tool 6 by means of which logs 7 may be grabbed. The crane 1 is in practice mounted on a cross-country vehicle, not shown, e.g. a forwarder or the like. A device according to the invention includes two components mounted on the jib lever 3, viz . a house 8 which houses a reel or drum 9, as well as a dolly 11 serving as a locking device for a rope 10. As may be clearly seen in fig 1, house 8 and dolly 11 are separated from each other, the house being placed near the inner end of the jib lever 3, while the dolly is placed in the area of the free, outer end of the jib lever. Reference is now made to fig 2 and 3, which illustrate how the reel 9, in a known way per se, includes or co- operates with a spring 12 which is stretched when the rope is unwound and pulled out and which, in the stretched state, always strives to rewind the rope on the reel. However, a schematically indicated retaining mechanism, known per se, cooperates with the rope, which retaining mechanism is of such a nature that the rope may be pulled out a desired distance and retained in a desired position, the spring being activated by a jerk in the rope so as to wind up the rope on the reel. In fig 5 it may be seen that the dolly 11 consists of a suitably tubular cylindric body which at one end thereof has a flange 13 having an enlarged diameter and which, at the opposite end thereof, is attached to one of two mounting plates 14 which are interconnected via a bolt joint 1 " 5 so as to be mounted on the jib lever 3. A radially projecting finger 16 is applied to the envelope surface of the cylindric body 11, which finger, at a free end, is connected to a cross piece 17. In fig 4 is shown how the rope 10 includes a couple 18 in the area of the free end thereof. The shown device operates in the following way. In an inactive state, the free end or couple of the rope is applied in a suitable way to the dolly in a state ready for use. In case a separate log 7 during the work of loading the vehicle in question turns out to be inaccessible for the grab tool 6, i.e. be outside the range of action of the crane, the operator may, in a first step, pull out the rope 10 and couple the same 4 to the log, as is shown in fig 3. In this state, the jib lever 3 of the crane is turned to a position in which the distance between the dolly 11 and the log is minimal. When the rope is pulled out from the reel 9, the spring 12 is stretched; how- ever, without instantaneously striving to rewind the rope. In the next step, a half hitch of the rope is brought about around the dolly 11, a part running out from the reel being put on one side of the finger 16, while the part running against the log being put on the opposite side of the finger and outside the first-mentioned part. The spring of the reel is now activated by a jerk in the rope, which results in the rope being stretched. The device is now ready to dray or haul the log. This takes place by the fact that the jib lever of the crane is brought to turn in the direction inwards to the post of the crane (not shown) . In doing so, the rope is locked against the dolly by the outer part, the log following in the pulling direction. When the log has been pulled in towards the crane a distance, the jib lever is again turned back towards the starting position thereof, the half hitch of the rope around the dolly being slackened so that a certain part of the rope is automatically wound up on the reel during a renewed stretching of the rope. Hereafter, the operation is repeated in one or more additional steps, whereby the log is successively moved to a point at which it may be reached by the grab tool 6. When this has taken place, the rope is loosened from the log and then the grab tool may lift up the log on the load carrier of the vehicle. The concept "rope", as used above and in the subsequent claims, should be interpreted in the widest sense thereof. Thus, instead of genuine ropes, other arbitrary, flexible elements could also be used, such as wires, chains, straps, or the like. The word "rope" has consequently been chosen to create a conceptual simplicity in description and claims . Advantages of the device according to the invention are not only that a log may be hoisted into the area of the range of action of a crane by means of structurally simple, mechanical means, but also that the same is conveniently available on the jib lever of the crane and may be activated in a simple way for use only when the need arises. Feasible Modifications of the Invention The invention is not solely restricted to the embodiments described and shown in the drawings. Thus, the spring member known per se, which is used in order to realize the invention, may be designed in another way than the one exemplified in the drawings. It should also be mentioned that the in- vention may be used for draying or hauling other objects than logs. The device according to the invention may also be mounted and used on other turnable jibs than crane jibs for forestry vehicles, e.g. jibs of excavators.

Claims: o Claims 1. Device for vehicular cranes (1) of the type that comprises a jib (3) which is moveable in relation to the appurtenant vehicle and on which a rope reel (9) is mounted, said reel being, in a known way, loaded by a spring (12) which always strives to wind up a rope (10) on the reel and against the action of which a free part of the rope may be manually pulled out from the reel, c h a r a c t e r i z e d in that the reel (9) co-operates with a locking device in the form of a dolly (11) accompanying the crane jib, which dolly is fixedly applied to the crane jib (3) at a distance from the reel and by means of which the rope may be locked in a given point in order to enable the hauling in of an object (7) coupled to a free end of the rope by displacement of the crane jib. 2. Device according to claim 1, c h a r a c t e r i z e d in that the dolly consists of a cylindric body (11) which projects at an angle from the crane jib (3) and has a finger (16) projecting radially from an envelope surface thereof.

Inventors: TROIVE GOERGEN, TROIVE, GOERGEN
Applicants: TROIVE GOERGEN, TROIVE, GOERGEN
Application year: 1999
Main classification: B66C23
IPC codes: A01G23, B66D1