US3498665A

US3498665A - Safety device for use on the lifting frames of a container crane

Info

Publication number: US3498665A
Application number: US714885A
Authority: US
Inventors: Tauno Karttunen
Original assignee: Valmet Oy
Current assignee: Valmet Montreal Inc
Priority date: 1967-03-22
Filing date: 1968-03-21
Publication date: 1970-03-03
Anticipated expiration: 1987-03-03
Also published as: SE327518B; FI45850B; FI45850C; FR1558152A; DE1756010A1; GB1149338A; DE1756010B2

Description

T. KARTTUNEN March 3, 1970 v SAFETY DEVICE FOR USE ON THE LIFTING FRAMES OF A CONTAINER CRANE Filed March 21, 1968 H92 INVENTOR:

Tkaritunen ATTOI BS United States Patent 3,498,665 SAFETY DEVICE FOR USE ON THE LIFTING FRAMES OF A CONTAINER CRANE Tauno Karttunen, Jyvaskyla, Finland, assignor to Valmet 0y, Helsinki, Finland, a corporation of Finland Filed Mar. 21, 1968, Ser. No. 714,885 Claims priority, application Finland, Mar. 22, 1967, 858/ 67 Int. Cl. B66c 1/00 US. Cl. 29481 4 Claims ABSTRACT OF THE DISCLOSURE A safety device is used on lifting frames of a containerhoisting crane. The device prevents the turnable joining dowels from being disengaged while hoisting is in progress. These dowels are located in the corners of the lifting frame and they engage the corner pieces of the container being hoisted. The safety device includes a locking device which permits the turning of the dowels into their engaged position when the lifting frame is lowered upon the container. At the start of the hoisting, a locking element constituting a part of the locking device acts upon a joining dowel and prevents the dowels from being turned into their disengaged positions.

The present invention concerns a safety device for use on the lifting frames of a container-hoisting crane, which prevents the turnable joining dowels in the corners of the lifting frame, which engage with the corner pieces of the container, from being disengaged while hoisting is in progress.

When a container is hoisted with the aid of a lifting frame, an obvious risk of misadventure and accident is present in that the hoist operator may inadvertently or from lack of professional skill release the container from the lifting frame during hoisting and transport through the air, thus causing the container to fall. Some deplorable accidents that have happened in actual practice also serve to demonstrate that improvement of the situation is called for.

The present invention accordingly aims to furnish a safety device such that this device will render impossible the releasing of the container from the lifting frame during hoisting and during its transport through the air. The invention is accordingly mainly characterized in that the safety device consists of a locking device which partly protrudes in the downward direction from the corner of the lifting frame and which on lowering the lifting frame upon the container and on penetration of the joining dowels into the corner pieces of the container, when it is pressed against the corner piece, assumes a position in which it is possible to turn the lifting frame joining dowels into their engaged position for hoisting, and which at the start of hoisting-and when the joining dowel on lifting the frame is raised inside the corner piece through a certain distance of play to rest against the inner surface of the container corner pieceis released and assumes its locking position in which the locking element provided in it engages with its counterpart, which acts positively on the joining dowel.

The invention is described in closer detail in the following with reference to one embodiment of the invention which is presented in the attached drawing. FIG. 1 displays schematically, and partly in section, an elevational view of one corner of the lifting frame, on which a safety device according to the invention has been mounted. FIG. 2 shows the same as FIG. 1, but as viewed from above.

The

reference numerals

1 and 2 indicate beams belong- 3,498,665 Patented Mar. 3, 1970 ing to the lifting frame, which are connected at each of the four corners of the lifting frame with a housing 3. Inside each housing 3 there is a joining dowel 8 which is turnable in previously known manner and which may be turned by means of its governing elements through 90 degrees between two extreme positions. Dash-and-dot lines in the drawing indicate one upper corner of the container and the corner piece 9 belonging to it, which conforms, for instance, to the respective standards. On the upper side of the corner piece there is an oblong opening 10, through which the conical joining dowel 8 of substantially similar shape in its maximum cross section may enter into the corner piece when it is in one of its extreme positions. This particular position has been shown in FIG. 1. When the joining dowel 8 has entered the corner piece, it is turned through 90 degrees into its other extreme position, whereby it cannot any more come out through the opening 10, and the hoisting may begin.

As has been said before, lifting frames known heretofore have the fault that it is possible for the operator to make the joining dowels turn into their other extreme position while the container is being hoisted and transported through the air, with the natural conseqence that in such instances the container has been released from its joining to the lifting frame and has fallen down. The desire is, in the present invention, to eliminate this possibility, and in the embodiment shown in the drawing, which is simple in design and advantageous, the problem has been solved with the aid of a pin-like locking device 4, which is free to move vertically between two extreme positions. In FIG. 1 its lower extreme position has been illustrated, in which the lower end of the pin protrudes from the bottom 15 of the corner housing 3 of the lifting frame. Attached to the pin is a tongue-like locking element 6, which moves vertically along with the pin 4. The joining dowel 8 carries a flange 11 which, although it is a separate piece, has been so attached to the joining dowel 8 that it follows the dowels movements and turns along with it. In the flange 11 two

notches

7 and 14 have been provided, which serve as receptacles for the locking element 6.

A safety device according to the invention operates as follows. Assuming that from the situation displayed in FIG. 1 the lifting frame is further lowered by such an amount that the lower bottom surface 15 of its corner housing 3 comes to rest against the upper surface 16 of the container corner piece 9, at which also the lower end of the pin 4 will rest against the upper surface 16 of the corner piece 9 and the pin will be raised by a distance equal to the length of that part of the pin which protrudes downwardly from the bottom 15 of the housing. At the same time the spring 5 is compressed and the locking element 6 rises out of its receptacle 14 and remains in a position above the flange 11. The joining dowel 8 has now been released from its locking and it may be turned into the position in which it binds the lifting frame to the container. This binding, or joining, is accomplished in previously known manner in that the actuating device of the lifting frame (not shown), which nowadays often is pneumatic or hydraulic, exerts a pull on the rod 13 (FIG. 2; omitted in FIG. 1 for the sake of clarity). The rod 13 passes through an opening 18 of the housing 3 and is pivotally attached at one end to the bell crank 12, which in its turn has been connected at its other end rigidly to the joining dowel 8, so that by pulling on the rod 13 the joining dowel 8 can be made to turn 90 degrees in clockwise direction, whereby the face of the conical tip of the joining dowel 8 meets the inside upper surface 19 of the corner piece 9. During progress of the actual hoisting the

surfaces

15 and 16 are thus separated by a small space. At the same time, however, the pin 4 and the locking element 6 integral with it have moved downward under action of the spring 5 and of gravity by such an amount that the nut 20 at the upper end of the pin has come into contact with the upper surface of the lug 17. Furthermore, the locking element 6 has been lowered into its receptacle 7, whereby the joining dowel 8 has also been locked so that it cannot be turnedeven if this should be attemptedbefore the container has been deposited on a firm base and the lifting frame has been lowered to be supported by the container corner pieces 9 so that the

surfaces

15 and 16 meet and the pin 4 is raised and the locking element 6 releases the joining dowel 8 from its locking.

As it is, the design shown in the drawing provides two locking positions, corresponding to the

notches

14 and 7. The notch 7 is more important from the safety viewpoint. However, locking by means of the notch 14 is needed in order to prevent the joining dowel 8 from being turned into its engagement position unless the dowel 8 has entered deeply enough into the hole 10 of the corner piece, or if the lifting frame is hanging in the air. The dowel cannot be turned back into its disengaged position if it has been inadvertently turned into its engaging position and locking by means of the notch 7 has taken place, except by pressing the pin 4 in by hand. It is moreover possible to accomplish with the aid of the locking by means of notch 14 simultaneous safety control of the joining dowels 8 of all four corners by functionally connecting together and to one and the same actuating device the pull rods 13 of all four joining dowels, which serve to turn these dowels through 90 degrees into the engaging or disengaged position, so that they may only turn simultaneously. In that case the turning of the joining dowels into the position in which they engage the corners of the container is not feasible unless all four dowels 8 have entered the corner pieces 9 so that the locking elements 6 of all dowels have been raised out of the notches 14.

Within the scope of the invention the locking problem may be solved also in a number of ways other than the drawing shows. The main thing is that from the bottom 15 of the housing 3 there protrudes a feeler organ, which may be a pin or, for instance, a toggle lever, and that the movement of this organ is transmitted to the organs which effect the locking. The male element-female element arrangement itself, which is used for locking, may be varied in a number of ways. For instance, the male element of the locking unit may equally be mounted in rigid functional attachment with the dowel 8, in which case the female element in its turn is in functional contact with the said feeler organ. Depending on the design and mode of operation of the actuating mechanism used in the lifting frame, it is sometimes possible that a safety device according to the invention must not necessarily be mounted in connection with all four dowel mechanisms. It may thus occasionally be sufficient if only one or two of the corners of the lifting frame are provided with such a safety device, or if the feeler organ of the safety device touches some point on the upper surface of the container other than its corner, but this implies that the joining dowels 8 at the corners of the lifting frame are functionally rigidly synchronized with each other. At all events it is advantageous in practice, and most often it is unavoidable, to use a safety device according to the invention at each of the four corners of the lifting frame.

I claim:

1. Safety device for use on the lifting frames of a container-hoisting crane, which prevents the turnable joining dowels (8) in the corners of the lifting frame which engage with the corner pieces (9) of the container from being disengaged while hoisting is in progress, characterized in that the safety device consists of a locking device which partly protrudes in the downward direction from the corner of the lifting frame and which on lowering the lifting frame upon the container and on penetration of the joining dowels into the. corner pieces of the container, when it is pressed against the corner piece, assumes a position in which it is possible to turn the lifting frame joining dowels (8) into their engaged position, and which at the start of hoisting-and when the joining dowel is raised inside the corner piece (9) through a certain distance of play to rest against the inner surface (19) of the corner pieceis released and assumes its locking position in which the locking element (6) provided in it engages with its counterpart (7), which acts positively on the joining dowel, preventing the joining dowels (8) from being turned into their disengaged position.

2. Safety device as in claim 1, characterized in that it consists of a pin (4) which is free to move in vertical direction between two extreme positions and which carries a tongue-like locking element protruding from its stem, this locking element engaging a receptacle notch (7) made for it in the joining dowel (8, 11).

3. Safety device as in claim 1, characterized in that acting upon the locking device a spring force (5) has been provided, which tends to move the locking device into its position consistent with locking.

4. Safety device as in claim 1, characterized in that such devices have been placed in connection with all the joining dowels (8) of the lifting frame so that when the turning motions of the joining dowels have been organically mutually coupled by means of linkage rods or by some other common turning mechanism, the safety devices prevent, each of them separately, the joining dowels (8) from being turned into their engaged or disengaged position unless the pins (4) of all these safety devices and their locking elements (6) have been disengaged from their receptacle notches (7 or 14).

References Cited UNITED STATES PATENTS 3/1963 Heinmiller. 2/1968 Reich 294---83 U.S. Cl. X.R. 294-83