GB2076780A

GB2076780A - Load-lifting Sack

Info

Publication number: GB2076780A
Application number: GB8113361A
Authority: GB
Original assignee: Supra AB
Current assignee: Supra AB
Priority date: 1980-05-30
Filing date: 1981-04-30
Publication date: 1981-12-09
Also published as: NL8102458A; NO153251C; FI65205B; SE455085B; NO811702L; NO153251B; FI811524L; SE8004049L; IT8121524A0; IT1138308B; GB2076780B; FI65205C; DE3119744A1

Abstract

A sack comprises a casing (10) to take the stress when the sack is lifted together with its contents. The casing is held gathered together by means of a rope at one of the casing end regions (12) or (11). At one or both ends two or more casing end flaps (18), formed by axially slitting the casing, are individually gathered by rope (21). This rope has a part which connects the end flap in question to, or itself forms, a lifting loop, or which rope part includes that rope part with which another of the end flaps is gathered. The sack may have four flaps at one end, may be double-walled (lifting loops then engaging a folded-over upper end of the sack), or may have a lifting rope extending to the bottom of the sack, Figure 6. <IMAGE>

Description

SPECIFICATION A Sack The present invention relates to a sack which includes a sack casing which takes up the stresses and strains in the sack when the sack is lifted together with its contents, whereat the casing material is held gathered together with the aid of rope adjacent at least one of the casing end regions forming the bottom part and the upper part of the sack. More particularly, the invention relates to a so-called large sack for transporting bulk material, such as powderous or granulated fertilizers, ground or non-ground seed, coffee beans, Portland-type cement etc., in weights of several hundred kilos, e.g. from 1 to 2 tons.

In known sacks of this kind it is difficult to achieve in a reproduceable manner the strength required on those fastenings between the gathered casing material and rope at the bottom and/or upper part of the sack which are subjected to the stresses and strains created by the weight of the goods carried in the sack, particularly in view of the fact that there is normally prescribed five-fold safety factor with regard to such fastenings.Fastenings of the kind effected by binding the gathered casing material with rope are preferred, however, to other types of fastenings, since they render manufacture of the sack less expensive and more simple and, in those cases when the rope simultaneously forms a lifting loop wherewith the sack, together with its contents can be lifted, facilitate the handling of the filled sack because at least some part of the loop is normally always readily accessible to a lifting hook or the like, even though the sack should have toppled over or have been laid in an unconvenient position. A fastening of the kind described also enables the load to be distributed relatively uniformly throughout the whole of the casing material, with subsequent saving of material since it is not then necesary for the casing to be dimensioned to withstand highly concentrated stresses and strains.

The object of the invention is to provide a sack construction in which the aforementioned disadvantage is at least substantially eliminated and thus the reliability of the fastenings between casing material and rope is greatly increased.

To this end there is proposed a sack of the kind described in the introduction, which sack is further characterized in that at one or both of said end regions of said casing two or more casing end flaps, formed by slitting the casing end region in question substantially axially are individually gathered and held gathered by binding the same with a part of rope which also exhibits a part extending from the binding location, which part connects the end flap in question to, or itself forms, a lifting loop wherewith the sack, together with its contents, can be lifted, or which rope part includes that rope part with which a further of said casing end flaps is individually gathered and bound.By means of this arrangement there is obtained from the strength aspect and particularly with regard to the risk of sliding between casing material and rope at the fastening locations, substantially more flavourable dimension relationships between rope and the gathered casing material, thereby providing the possibility of manufacturing still larger so-called large sacks than those hitherto produced, without departing from the safety requirements.

According to one advantageous embodiment of the invention, at least two end flaps arranged at the casing end region forming the bottom part of the sack are individually gathered and bound by adjacent parts of one and the same rope.

According to another advantageous embodiment of the invention, at least two casing end flaps are individually gathered and held gathered by mutually spaced parts of one and the same rope, the intermediate part of the rope located between said rope parts forming a lifting loop. The casing end flaps may then be located at the casing end region forming the bottom of the sack and the intermediate part of said rope doubled back through the interior of the sack space intended to receive the goods to be carried by the sack, and out through the upper part of the sack to form a lifting loop.

These embodiments enable the rope to be used to the full, by whichis meant that the rope can be used to carry the load for which it was designed, even though it has been knotted, as explained hereinafter.

In the aforementioned embodiments of a sack constructed in accordance with the invention, the gathered and bound casing end flaps are located either at the top or the bottom of the sack, and hence when the sack is lifted by the loop formed by said rope, the load is concentrated more on one part of the sack than the other. While this may be acceptable in the case of sacks of moderate size, it might be preferred in the case of very large sacks to ensure that the load is uniformly distributed throughout the casing.

This can be achieved with a particularly advantageous embodiment according to the invention, in which at least two casing end flaps are formed at each of the casing end regions forming the bottom part and the upper part of the sack; in which the two casing end flaps individually gathered and bound by mutually spaced parts of one and the same rope are each located in a respective one of said casing end regions; and in which the intermediate part of the rope extends upwardly from the binding location at said bottom part, through the interior of the sack space intended to receive the goods to be carried, and out through the upper part of the sack, to there form a lifting loop.

An advantage is afforded when the knots used to hold the sack material together at said gathering locations are self-tightening, and also preferable self-locking, knots such as single or double sheet bends.

Further characterizing features of the invention are set forth in the dependent claims and will be disclosed, together with advantages intrinsic therewith, in the following description of a plurality of exemplary embodiments of the invention illustrated in the accompanying drawings.

Figure 1 is a side view, partly in section, of a first embodiment of the sack according to the invention.

Figure 2 is a side view of the upper part of a second embodiment of the sack according to the invention.

Figures 3 and 4 are side views of the upper part and the under part of a third and fourth embodiment respectively of the sack according to the invention.

Figure 5 is a side view, partially in section, of a fifth embodiment of the sack according to the invention.

Figure 6 is a side view of a sixth embodiment of the sack according to the invention.

In Figure 1 of the drawings, in which equivalent or substantially equivalent elements are identified by the same references, the reference 10 identifies a sack casing having an upper part 11 and a bottom part 12. Arranged in the casing 10, which is subjected to the stresses and strains created by the weight of the goods in said sack, particularly when lifting said sack together with its contents, there is arranged at 1 3 an enclosed inner sack 14 preferably made of a water-tight material, whereat the inner sack 14 may have slightly larger dimensions than the sack casing 10 so as to be supported thereby and so as not to be subjected itself to any appreciable stresses and strains.

The casing 10 is formed from a tubular element, preferably made of a woven material, which is gathered at its centre region and there bound by means of a tie 1 5. Of the tubular parts 16, 17 separated by the tie, one is folded back upon the other such that said bound region of the tubular folded elements form said bottom part 12 while said separated parts of the tubular element extend in one and the same direction and form an outer and inner casing layer. At the upper part 11 the double casing 10 is provided at diametrical opposite sides with axial slits to form casing end flaps 18, whereat the casing end flaps defined by said slits and comprising double-folded casing material are individually gathered together and bound at 19 and 20 respectively with parts of one and the same rope 21.The part of the rope 21 located between the binding locations forms a lifting loop wherewith the sack, together with'its contents, can be lifted by means of a lifting hook or corresponding element of a lifting means (not shown) inserted in said loop. The casing end flaps 18 are, to advantage, individually gathered together and tied by associated rope parts with the aid of self-tightening, and preferably also self locking knots, such as the single sheet bends illustrated or double sheet bends. Particular advantage is obtained when, as illustrated, the flaps 18 are tied by end parts of the same rope 21, since the rope is then utilized to the full. If a rope is knotted, the knot is considered only half as strong as the remainder of the rope.When lifting a sack by means of a hook inserted in the lifting loop, the intermediate part of the rope forming the lifting loop will bear the whole weight of the filled sack, while each knot will only bear half the weight. It lies within the scope of the invention, however, to bind the flaps 1 8 with parts of separate ropes, the portions of which extending from the binding location each connecting the end flap in question to, or itself forming, a lifting loop, as indicated in chain lines at 22 and 23 respectively in Figure 1.

Figure 2 illustrates the upper part of a sack casing 1G which has an upper part 11 and which accommodates an inner sack 1 4. By making four, substantially axially extending slots in the upper region of the casing 10, there has been formed four end flaps 24 which have been separately gathered together at 25 and tied with respective end portions of two ropes 26, 27 in the manner described with reference to Figure 1. The parts of the ropes 26, 27 located between respective binding locations 25 are passed through a ring 28 by which the sack, together with its contents, is intended to be lifted, as indicated by the hook 29 shown in chain lines.Alternatively, the sack can be lifted by means of the loops formed by said rope parts, whichshould, in this case suitably be held together for exampie by means of an adhesive tape, thereby to avoid the risk of the sack being lifted solely by one of the loops.

Figure 3 illustrates the upper and lower portions of a sack casing 10 having an upper part 11, a bottom part 12 and an inner sack 14. The casing 10 is formed from a tubular element which has been gathered together at the middle thereof and one of the parts 1 6, 1 7 separated by the gathering location folded back upon the other, such that said parts extend in the same direction, one within the other. At each end the doublewalled casing 10 thus formed is provided at diametrically opposed sides thereof with axially extending slits. Placed in the upper fold 30 formed when folding back the tubular element is closed rope loop or rope ring, of which parts 31, 32 have been drawn through the upper slits, to form two lifting loops, by which the sack, together with its contents, can be lifted. When subjecting the parts 31,32 to tension forces, the upper part 11 of the casing 10 is drawn together said parts 31, 32 can be fastened to one another in their extended position, to hold the upper part 11 gathered and substantially closed. The upper sack part 11 of the embodiments illustrated in Figures 1 and 2 above, and the embodiment described hereinafter with reference to Figure 5, can also be held substantially closed by connecting together the flaps 1 8 or the rope parts extending therefrom.The bottom 12 is formed by individually gathering together the casing end flaps 33, which are formed by the lower slits and which comprise double layers of casing material, and binding by the aid of the opposite end parts of a rope 35, whereat the part of the rope located between the binding locations is relatively short so that a substantially closed sack bottom 12 is formed. Alternatively, the bottom end flaps associated with the inner casing layer 1 7 and the outer casing layer 1 6 may be joined together in pairs, preferably with the aid of two ropes, in the same manner as that described with reference to the flaps 33.Preferably, the flaps are tied with self-tightening and self-locking knots, such as single or double sheet bends, whereby the tension forces acting on the rope 35, when the sack together with its contents is lifted, strive to tighten the knots still further.

The sack illustrated in Figure 4 comprises a double-walled sack casing 10 with an outer and an inner casing layer 1 6 and 1 7 respectively, said casing 10 being formed by folding a tubular element back from the centre thereof in the manner described with referenct to Figure 3. In the fold 30 formed when folding back said tubular element there is arranged a tie 36 in the form, for example, of a rope which holds the upper end of the casing 10 together, to form a substantially closed upper sack part 11. A rope loop 37, which forms part of or is connected to the tie 36, extends out through relatively short axial slits 38 in the casing 10.The casing 10 encloses an inner sack 1 4 which is provided with a filling valve 39, which can be reached through an axial slit 40 in the casing 10 and which can be passed, either before being closed or after being closed, through the slit 40 and placed between the casing 10 and the inner sack 14 or between the casing layers 1 6, 1 7. Formed in the outer casing layer 16 in the lower end region of the casing 10 are two axially extending slits, such as to form two lower end flaps 33 which are individually held gathered together at 34 and bound by parts of a rope 35, substantially in the manner described with reference to Figure 3. The lower end part of the inner casing layer 1 7 is gathered in its entirety and tied at 41.To this end, there can be used a separate rope or, asillustrated, part of the rope 35 with which the end flaps 33 are bound and joined together.

The sack illustrated in Figure 5 includes a casing 10 having an upper part 11 and a bottom part 12, whereat the casing 10 accommodates an inner sack 14 having a filling valve 39 which can be reached through an axial slit 40 in the casing.

The inner sack 14 is formed from a tubular element, the ends of which are gathered around an upper and lower sleeve 42 and 43 respectively and secured by tying said ends with a rope, or in some other way. Extending through the interior of the inner sack is a relatively narrow hose 44 of liquid-tight and soft, pliant material, whereat each of the ends of the hose 44 is firmly clamped between a respective one of the sleeves 42, 43 and the inner-sack material. The casing 10 is provided at each of the opposite end regions thereof with two diametrically opposed, substantially axially extending slits, so that there are formed at both the upper part and the bottom part of the sack two end flaps 18 and 33 respectively.The four end flaps 1 8, 33 are gathered together individually at 1 9 and 34 respectively, and are bound and joined in pairs with the aid of two ropes 45. In the illustrated embodiment, one upper end flap 18 and one lower end flap 33 are gathered together and tied with the opposite end parts of the one rope 45, while the other upper end flap 1 8 and the other lower end flap 33 are gathered together and tied with the opposite end parts of the other rope 45.

Those parts of the rope 45 located between the binding locations extend longitudinally displaceably within the hose 44, from the bottom part 12 of the sack, up through the container space of said sack and through the sleeves 42, 43, and out through the upper part of the sack, there to form lifting loops in the manner illustrated in the Figure. When the sack together with its contents, is lifted by means of a lifting hook or the like passed through the loops, the load transferred from each rope 45 to the casing 10 will be substantially uniformly distributed in a favourable manner between the associated end flaps 18 and 33 at the upper and lower parts of the casing 10 respectively. Moisture and water able to penetrate along the ropes 45 is prevented from coming into contact with the goods in the sack by means of the hose 44.

The sack illustrated in Figure 6 also comprises a casing 10 having an upper part 11 and a bottom part 12. The casing 10 has arranged therein an inner sack (not shown) which is provided with a filling valve 39 which can be reached through an axial slit 40 in the casing 10. The inner sack is assumed to be formed in the manner described with reference to Figure 5 and to be gathered together at the ends around sleeves 42, 43 between which there similarly extends a hose 44 of soft, pliant water-tight material. The upper end of the casing 10 is held gathered around and is firmly connected to the sleeve 42 by means of a tie 46.In the lower end region of the casing 10 two end flaps 43 are formed by axially slitting the casing at diametrically opposed sides thereof, said end flaps being individually gathered together at 34 and bound by corresponding end parts of a rope 47, whereat the part of the rope 47 located between the binding locations 34 is of substantial length and is doubled upwardly through the interior of the sack space intended to receive goods, and out through the upper part 11 of the sack to there form a lifting loop. The rope part located in the sack interior passes up through the hose 44 so as to be isolated from the goods carried in the sack, and is longitudinally displaceable through the sleeves 42, 43 so that - when lifting the sack, together with its contents by said lifting loop, the loads which occur are transferred substantially solely to the bottom part 12.

The described and illustrated embodiments are not limitive of the invention, but can be modified within the scope of the following claims.

Claims

1. A sack which includes a sack casing (10) which takes up the stresses and strains in the sack when the sack is lifted together with its contents, whereat the casing material is held gathered together with the aid of rope adjacent at least one of the casing end regions forming the bottom part (12) and the upper part (11) of the sack, characterized in that at one or both of said end regions of said casing (10) two or more casing end flaps (18, 24, 33), formed by slitting the casing end region in question substantially axially, are individually gathered and held gathered by binding the same with a part of a rope (21,26, 35, 45, 47) which also exhibits a part extending from the binding location (19, 20, 25, 34) which part connects the end flap in question to, or itself forms, a lifting loop wherewith the sack, together with its contents can be lifted, or which rope part includes that rope part with which a further of said casing end flaps is individually gathered and bound.

2. A sack according to claim 1, characterized in that at least two end flaps (33) arranged at the casing end region forming the bottom part (12) of the sack are individually gathered and bound by adjacent parts of one and the same rope (35).

3. A sack according to claim 1, characterized in that at least two casing end flaps (18; 24; 18, 33; 33) are individually gathered and bound by mutually spaced parts of one and the same rope (21; 26; 45; 47), whereat the intermediate rope part located between two such parts forms a lifting loop.

4. A sack according to claim 3, characterized in that the casing end flaps (33) are located at the casing end region forming the bottom part (12) of the sack, and in that said rope intermediate part is doubled back through the inner of the sack space intended to receive goods to be carried by said sack, and out through the upper part of the sack, to there form a lifting loop (Figure 6).

5. An arrangement according to claim 3, characterized in that at least two casing end flaps (18, 33) are formed at each of the casing end regions forming the bottom part (12) and the upper part (11) 6f the sack; in that the two casing end flaps (18, 33) individually gathered and bound by mutually spaced parts of one and the same rope (45) are each located in a respective one of said casing end regions; and in that said rope intermediate part extends upwardly from the binding location (34) located at said bottom part, through the interior of the sack space intended to receive the goods to be carried, and out through the upper part of the sack, to there form a lifting loop (Figure 5).

6. A sack according to any one of claims 1-5, characterized in that the casing end flaps (1 8, 24, 33) are individually gathered and bound by associated rope parts with the aid of selftightening and preferably self-locking knots, such as single or double sheet bends.