US3362744A

US3362744A - Device for use with slings, particularly bag slings for use in unit loading

Info

Publication number: US3362744A
Application number: US525061A
Authority: US
Inventors: Ek Bengt Arne Arvid
Original assignee: Goeteborga Bandvaeveri
Current assignee: GOTEBORGS BANDVAVERI AB
Priority date: 1965-02-27
Filing date: 1966-02-04
Publication date: 1968-01-09
Anticipated expiration: 1985-01-09
Also published as: DE1456464A1; DE1456464B2; GB1065471A; NL6601258A

Description

Jan. 9, 1968 B. A. A. EK 3,362,744

DEVICE FOR USE WITH 5 GS, PARTICULARLY BAG LIN SLINGS FOR U IN UNIT LOADING Filed Feb. 4, 1966 INVENTOR BYh/M United States Patent Office 3,362,744 Patented Jan. 9, 196$ ABSTRACT OF THE DISCLOSURE The invention is a buckle for slings wherein a selflocking catch is provided which when in locking position is contained within the contour line of the buckle. Means are provided for easily releasing the self-locking catch and to hold it in such released position.

This invention relates to a device at slings particularly so-called bag slings intended for use in unit loading, i.e. slings which are maintained on the load from application until the load has reached its destination and which, if needed, can be used during transport for re-stowage. Slings of this type comprise a strap, provided at one end with a suspension loop and at the other end with a locking device consisting of a metal buckle through which passes the loop end of the strap.

In the loading of bags and the like with the aid of such slings it is important that the sling is maintained securely around the load when the lifting force is diminished or completely interrupted and that it is further tightened at any new lifting action, so as to prevent the load from falling free of the sling. It is likewise important that the sling can be easily released from the load when desired. Furthermore, it is important that no sharp or pointed details project from the locking device, since they might cause damage to the load unitsoften of considerable weightwhen these units are placed on top of each other, and thus also on top of a locking buckle. If the projecting details are parts constituting the very locking mechanism of the sling, this mechanism might be released by any load placed on top of it thereby loosening the grip of the strap around the load.

The object of the present invention is to provide a sling in which all these requirements are fulfilled, viz. a sling which has an automatically tightening grip around the load at lifting action, which does not slide off the load at depositing thereof, and which can be easily released from the load whenever desired. To bring about these advantages the device according to the invention is characterised by a spring loaded locking lever arranged to press the strap traveling in the metal buckle into firmly gripping engagement with said buckle at a point situated a minor distance above the line connecting the central point of the locking lever axis with the central point of that part of the metal buckle with which the locking lever is arranged to engage in the locking position, the locking lever and its spring being arranged in such a way that in the locking position they are contained within the contour lines of the metal buckle.

The invention will be described in detail in the following with reference to the accompanying drawing in which:

FIG. 1 shows the sling according to the invention, encircling a load,

FIG. 2 is a fragmentary plan view of the locking device for the sling, with some parts broken away, and

FIG. 3 is a section of the sling as illustrated in FIG. 2.

As shown in FIG. 1 the sling according to the invention consists of a strap 1 arranged to be wrapped around the load 2. At one of its ends, the strap 1 has a loop 3 by means of which the strap is suspended in a lifting hook 4 of a hoisting crane, not shown. At its opposite end, the strap 1 is provided with a locking device 5 arranged to be passed around the loop end 3 of the strap when the sling has been placed around the load 2.

As shown in FIGS. 2 and 3, the locking device 5 consists of a rectangular metal buckle 6 which, according to the illustrated modification, comprises two

side parts

7 and 8 interconnected through

transverse metal pins

9 and 10. A locking lever 13, operated by a spring 12, is journalled about an axis 11 arranged between the pins 9 and 1t) and parallel thereto, one end 14 of the locking lever 13 being urged by the spring 12 to engage with the pin 10 at a point situated, as can be seen in FIG. 3, somewhat above an imaginary line interconnecting the central points of the

pins

9 and 10.

The attachment of the sling around the load takes place in the following manner. The loop end 3 of the strap is inserted from underneath (with relation to FIG. 3) between the end 14 of the locking lever 13 and the metal pin 10, and the strap 1 can then be tightened around the load 2 usually consisting of one or more bags, so that upon pulling movement of the strap 1 in this direction the locking lever 13 is turned upwards against the action of the spring 12, the end 14 of the lever swinging into its upper, releasing position. This upward movement of the lever 13 thus occurs when the load is being lifted, the angle or automatically adjusting itself to 120.

When the load is being deposited it will exert a pulling action on the strap 1 in the opposite direction but the friction between the strap 1 and the lever 13 together with the action of the spring 12 urge the locking lever end 14 to securely press the strap 1 against the transverse pin it) so that the sling stays looped around the load to be used at the next hoisting, for example at stowing or unloading.

To release the sling from the load, the operator presses with a finger on that end 15 of the locking lever 13 which is opposite the end 14 thereof so that this latter end is swung upwards, releasing the strap 1. To facilitate the swinging movement of the locking lever 13 a lever 17 (FIG. 3) is journalled about an axis 16, one end 18 of said lever 17 exerting pressure on the locking lever end 15 so as to swing it downwards (with relation to FIG. 3) whereby the strap 1 is released.

In this connection it should be noted that considerable powers are brought into play at the locking of the sling, and the lever 17 as shown in FIG. 3 has in practice proved insufficient to counteract the locking force of the locking lever 13. It has therefore been necessary to provide the lever 17, at the end 18 thereof, with a shoulder projecting from the underside of the lever 17 in order to improve the lever action, i.e. to reduce the distance between the axis 16 and the point of contact of the lever with the locking lever 13. This simple modification has proved sufiicient to ensure an easy release of the locking device. Some considerable concentration of force is needed to do away with the wedge effect, as obtained and to give an example thereof it should be mentioned that in the case of a sling, having a thickness of approximately 5 mm. and used to lift a cargo loading the sling with 1000-1 kilos, the sling is extended to such a degree that its thickness is approximately 2.5 mm. When the lifting action is completed and the sling unloaded, a locking intensity of 200-300 kilos is obtained. It is readily understood that considerable power is required to nullify a locking intensity of this kind and, in order that separate tools be dispensed with, special steps must be taken, as in the device according to the invention.

The invention is not limited to the embodiment as illustrated in the drawing and described in the foregoing but several modifications thereof are possible Within the scope of the appended claims. The axis 11, for instance, might have such cross section as to enable it to cooperate with the blades forming the locking lever 13, thus providing the spring action required to secure the strap 1 against the pin 10. The rectangular metal buckle 6 can be shaped in many difierent ways. Furthermore, the lever 17 might be spring actuated to assist in pressing the locking lever end 14 against the pin it).

What I claim is:

1. A sling arrangement, particularly bag slings comprising a strap having one suspension loop end and one locking device end, a locking device comprising a metal buckle to be passed over said suspension loop end of said strap, a locking lever pivotally mounted in said buckle, a spring urging said lever to press said strap running in said metal buckle into gripping engagement with said metal buckle at a point situated a short distance above the line connecting the central point of the axis of said locking lever with the central point of the metal buckle part with which said locking lever is arranged to engage in the locking position, said locking lever and said spring when in locking position being located within the contour lines of said metal buckle and a pivoted lever is located within said buckle adjacent said locking lever to force said locking lever out of gripping engagement with said strap.

2. A sling arrangement as set forth in claim 1 wherein said last named lever is spring loaded,

3. A sling arrangement as set forth in claim 1 wherein a spring lever is provided pivotally mounted in said buckle to force said locking lever out of gripping engagement with said strap.

4. A sling arrangement as set forth in claim 1 wherein two spring leaves form said locking lever, an axis arranged for cooperation with said two spring leaves and designed in a manner corresponding to said spring leaves, in order to bring about the swinging movement of said locking lever into locking position and a lever is provided to force said locking lever out of gripping engagement with said strap.

5. A spring arrangement as set forth in claim 4 wherein said last named lever is spring loaded.

References Cited UNlTED STATES PATENTS 292,934 2/1884 Menzel 24134 416,985 12/1889 Beattie 24-170 FOREIGN PATENTS 329,439 5/ 1930 Great Britain.

GERALD M. FORLENZA, Primary Examiner.

G. F. ABRAHAM, Assistant Examiner.