GB2230310A

GB2230310A - Expansible and retractible tubular means

Info

Publication number: GB2230310A
Application number: GB8908390A
Authority: GB
Inventors: Duglan Jarvis
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-04-13
Filing date: 1989-04-13
Publication date: 1990-10-17
Also published as: GB8908390D0

Abstract

An expansible and retractible means comprises a length of resilient, tubular, fluid impervious material 10 closed at at least one end, said tubular material over at least a part of its length being formed to a required configuration with parts of the length 9 in side-by-side relationship, and there being a means 5 of causing an expansion or contraction of the tubular material over at least the said part of its length of required configuration. Thus with the tubular length fluid filled, a part of its length can be contracted to cause the fluid to expand the other part of the length which may be formed as a helical winding or as a flat concertina. Equally the tubular length may be filled with an electrorheometric fluid to which an electric charge can be applied to convert the fluid to solid gel form, and when the heating effect on the fluid is such as to cause it and hence the tube to expand. The expansible and retractible means can be used as a connector for pipes and/or rods, can parody a muscle function, or respond like a tentacle, or can be used for assimilating a peristaltic action in a tube. <IMAGE>

Description

CONNECTOR This invention relates to connectors and is particularly but not necessarily exclusively concerned with connectors for rods and/or tubes, cables, bars, and the like.

There are a considerable number of applications in the medical and non-medical fields where the same or disimilar items need to be secured positively together, such as, for example, rods and/or tubes of the same or of different diameters, rods and/or tubes to cables and rods/tubes/cables to a flattened or otherwise non-circular opening of a box-like section or in a component. It is equally so that in both the medical and non-medical fields, a bending/flexing' or pivoting action is required, with a degree of control imposed over the bending/flexing or pivotal movements required. Particularly in the medical field there is the frequent need for contrivances that can parody a muscle function or respond like a tentacle.

In addition to the above there are other fields of activity such as in the handling of cell/fluid mixtures such as blood, where there is a need to find an alternative to a peristaltic pump to provide a gentler handling of the mixture.

The object of the invention is to provide a means that in principle can provide a relatively simple and cost effective solution to the problems mentioned above.

According to the present invention, an expansible/contractible means comprises a length of resilient, tubular, fluid impervious material closed at at least one end, said tubular material over at least a part of its length being formed to a required configuration with parts of the length in side-by-side relatioship, and there being a means of causing an expansion or contraction of the tubular material over at least the said part of its length of required configuration.

Thus, the required configuration over a part of the tubular length may be a helical winding of the tubular length, or may be the formation of the tubular length into a flat zigzag or concertina. In either instance, the tubular length can be closed at each end and a part of the tubular length can be left as a tail and to which pressure can be applied to cause an expansion of the tube over the length formed as a helix or a concertina hy the peristaltic action of the fluid filling within the tube. Alternatively, one end of the tubular length can be connected to a fluid reservoir.

The means of applying pressure to a part of the tubular length e.g., the tail when provided, may be a relatively simple wedge or camming means, able to be moved from a first position where no pressure is applied to the tubular length, to a second position where pressure is applied. Alternatively a suitable means to contract the reservoir can be provided.

As an alternative to the application of pressure to cause the required expansion, and of additional value when a high degree of rigidity is required of the connector, the fluid filling may be an electrorheometric fluid to which an electric charge can be applied to convert the fluid to solid gell form, and when the heating effect on the fluid is such as to cause it and hence the tube to expand.

It will of course be understood that the application of pressure and an electrorheometric fluid filling can be provided in one and the same connector, and where the first application of pressure causes a connection to be made, and the subsequent application of an electrical charge to the fluid generates a still more secure and rigid connection.

According to a further aspect of the invention a connector for rods and/or tubes of the same or different diameters comprises a length of resilient, tubular, fluid impervious material closed at least one end, said tubular material over at least a part of its length being formed o a required configuration with parts of the length in side-byside relatioship, and there being a means of causing an expansion or contraction of the tubular material over at least the said part of its length of required configuration.

According to a still further aspect of the invention, a pivotal connector comprises two relatively rigid members pivotally secured together, a length of resilient tubular material formed over part of its length as a flat concertina shape, the tubular length being secured to one said pivotal member along its length and connected to the other said pivotal member by a relatively rigid connecting member, and said tubular length forming a closed circuit for fluid and being suitably connected to a fluid reservoir.

According to yet another aspect of the invention, a flexible or bendable member comprises two lengths of resilient tubular material each formed over part of its length as a flat concertina shape, the tubular lengths being secured to opposite sides of a flexible membrane, and each forming a closed circuit for fluid from respective reservoirs suitably connected to the tubular lengths.

According to yet another aspect of the invention, a flexible or bendable member comprises at least three lengths of resilient tubular material each formed over part of its length as a flat concertina shape, the at least three lengths being connected together along their edges, and each forming a closed circuit for fluid and being suitably connected to respective fluid reservoirs.

According to yet another aspect of the invention, a pump comprises a number of lengths of resilient tubular material, each formed over part of their length into helical configuration and each forming a closed circuit for fluid and being suitably connected to respective reservoirs the tubular lengths surrounding and lying in close spaced relationship along the length of a fluid supply tube, and when the helical parts of the tubular lengths can be sequentially expanded and contracted.

The invention will now be further explained by way of example only with reference to the accompanying drawings, in which:- Figure 1 is a schematic sectional view of the invention in the form of a connector for connecting a rod to a tube; Figure 2 corresponds to Figure 1 but shows the connection of two tubes of different diameters; Figure 3 corresponds to Figure 2 but shows an alternative means of connecting two tubes of different diameter; Figure 4 is a perspective view of an alternative form of construction of connector in acco, iace with the invention; Figures 5 and 6 are schematic views of the invention in the form of a controlled pivotal connector; Figures -7 and 8 are schematic views of the invention in the form of a controlled bending/flexing device;; Figure 9 is a schematic view of the invention in the form of a bending/flexing device capable of universal directional movement; and Figure 10 is a schematic view of the invention in the form of a pump.

In Figure 1, a connector comprises a length of tubular material formed as a helix 1 over part of its length, and having a tail 2 extending from one end of the helix. Thus with the helix located on a spigot 3 extending from the end of a rod LI, the tail 2 can be laid along the length of the rod, and overlaid by a rotatable wedge 5 encircling the rod with then the spigot 3 and helix 1 inserted into the end of a tube 6, a simple rotation of the wedge 5 compresses the tail 2 to force fluid into the helix 1, the resultant expansion of which causes the tube 6 to be locked to the spigot and hence the rod, 50 hereby forming a most effective connection between a rod and a tube. Here it will be understood that the rod could equally well be a cable.

In the second embodiment exemplified in Figure 2, two tubes 7, 8 of different diameters are to be connected, but it will be uderstood that the tube 7 of smaller diameter could equally well be a rod or a cable. Here, a helical tube 9 is provided located in the end of the tube 8 of larger diameter, the helix having a tail 10 passing through a hole 11 in the wall of the tube to lay along its outer face and be encircled by a rotatable wedge. Thus with the tube 7 inserted into the helix, simple rotati#. #f the wedge causes an expansion of the helix to lock the tube 7 to the tube 8.

When two tubes of considerably different diameters are to be connected, it is possible to employ two connectors to collaborate with each other a-s is illustrated in Figure 3.

Here a first helix is positioned within the end of a larger tube 11, with its tail passing through a hole in the tube wall, to lay long the periphery of the tube where it is encircled by a rotatable wedge 12. A second helix 13 is located around the end of a smaller tube ill with its tail lying along the tube and encircled by a rotatable wedge.

Thus, with the second helix inserted into the first helix, both wedges can be activated to expand both helixes to lock the larger to the smaller tube.

Figure LI illustrates the invention when in the form of a flat concertina 15, and where the flat concertina can be wrapped around an item of any cross-sectional shape, and be inserted into an orifice of corresponding shape. Here, a tail 16 to the concertina is laid along the item 17 to be secured in the orifice, and encircled by a screw tightenable band (or a rotatable wedge of the item 17 should it be circular). Tightening the band or rotating the wedge causes an expansion of the tube forming the concertina to lock the item to the orifice.

In all of Figures 1 to 4, the fluid employed to fill the tube can be an electrorheometric fluid. Thus after initial activation of the mechanical means applying pressure to the tails to cause expansion of the helices or concertina by the peristaltic effect of the fluid, an electrical charge can be applied to the fluid to convert it to a solid gell for so long as the charge is maintained, with the advantage of the heating effect on the fluid itself causing an expansion of the tube to add significantly to the locking effect whilst at the same time creating a rigid connection.

In Figures 5 and 6, a pivotal connector is shown.

Here the means of the invention is of flat concertina form 18 with one end connected to a reservoir 19. The concertina 18 is secured to one member 20 of a pivotal connector, and a rigid connecting member 21 is provided between the concertina and the second member 22 of the pivotal connector. Thus, with the flexible tube empty the two members 20 and 21 are in line (Figure 5) and when fluid is expelled from the reservoir, the tubular material over the concertina length expands to push the member 22 to its pivotted position.

In Figures 7 and 8, two means of the invention are provided, both formed as flat concertinas 23, 24 and connected to reservoirs 25, 26, and secured to opposite sides of a flexible membrane 27. Thus with both concertinas empty, the device is straight (Figure 7) and with fluid from one reservoir 26 emptied, its concertina 24 expands and the device assumes a curved configuration (Figure 8). It will be understood that by expelling fluid from the reservoirs to different degrees, different degrees of flexing can be achieved.

In Figure 9 four lengths 28 of tubular material are provided each formed as flat concertinas and connected to respective reservoirs 29, and the concertinas being connected together to form a box-like structure. Thus, with the fluid in the reservoirs expelled to different degrees, different expansions can be caused in each concertina to effect flexing or bending to a required degree and in required direction.

Figure 10 shows the invention in the form of a pump.

Here a number of tubular lengths 30 of helical configuration are provided each connected to a respective reservoir 31 and the lengths are placed over a flexible feed tube 32. The fluid in the reservoirs is sequentially expelled and returned, such that the first helical length expands to contract the tube 32, and contracts as the second helical length expands to contract the tube, and so on, to provide a gentle pumping action on fluid within the tube 32.

Claims

LbAlPlb

1. An expansible/contractible means comprising a length of resilient, tubular, fluid impervious material closed at at least one end, said tubular material over at least a part of its length being formed to a required configuration with parts of the length in side-by-side relationship, and there being a means of causing an expansion or contraction of the tubular material over at least the said part of its length of required configuration.

2. An expansible/contractible means as in Claim 1, wherein the required configuration over a part of the tubular length is a helical winding of the tubular length.

3. An expansible/contractible means as in Claim l, wherein the required configuration over a part of the tubular length is by forming the tubular length into a flat zig-zag or concertina.

4. An expansible/contractible means as in any of Claims 1 to 3, wherein the tubular length is closed at each end and a part of the tubular length is left as a tail and to which pressure can be applied to cause an expansion of the tube over the length formed as a helix or a concertina by the peristaltic action of a fluid filling within the tube.

5. An expansible/contractible means as in any of Claims 1 to 3, wherein one end of the tubular length is connected to a fluid reservoir.

6. An expansible/contractible means as in any of Claims 1 to 4, wherein the means of applying pressure to a part of the tubular length is a relatively simple wedge or camming means, able to be moved from a first position where no pressure is applied to the tubular length, to a second position where pressure is applied.

7. An expansible/contractible means as in Claim 5, wherein a means to contract the reservoir is provided.

8. An expansible/contractible means as in Claims 1 to 7, wherein the fluid filling is an electrorheometric fluid to which an electric charge can be applied to convert the fluid to solid gell form, and when the heating effect on the fluid is such -as to cause it and hence the tube to expand.

9. A connector for rods and/or tubes of the same or different diameters comprising a length of resilient, tubular, fluid impervious material closed at at least one end, said tubular material over at least a part of its length being formed to a required configuration with parts of the length in side-by-side relationship, and there being a means of causing an expansion or contraction of the tubular material over at least the said part of its length of required configuration.

18. A connector for rods and/or tubes of the same or different diameters as in Claim 9, wherein expansion of said part of the length of tubular material is caused by compression of an end length of said tubular material to cause a fluid filling in the tubular material to expand said tubular material over said at least part of its length.

11. A connector for rods and/or tubes of same or different diameters as in Claim 9 or Claim 181 wherein the tubular length is filled with an electrorheometric fluid to which an electric charge can be applied to convert the fluid to solid gell form, and when the heating effect on the fluid is such as to cause it and hence the tube to expand.

12. A pivotal connector comprising two relatively rigid members pivotally secured together, a length of resilient tubular~material formed over part of its length as a flat concertina shape, the tubular length being secured to one said pivotal member along its length and connected to the other said pivotal member by a relatively rigid connecting member, and said tubular length forming a closed circuit for fluid and being suitably connected to a fluid reservoir.

13. A flexible or bendable member comprising two lengths of resilient tubular material each formed over part of its length as a flat concertina shape, the tubular lengths being secured to opposite sides of a flexible membrane, and each forming a closed circuit for fluid from respective reservoirs suitably connected to the tubular lengths.

14. A flexible or bendable member comprising at least three lengths of resilient tubular material each formed over part of its length as a flat concertina shape, the at least three lengths being connected together along their edges, and each forming a closed circuit for fluid and being suitably connected to respective fluid reservoirs.

15. A pump comprising a number of lengths of resilient tubular material, each formed over part of their length into helical configuration and each forming a closed circuit for fluid and being suitably connected to respective reservoirs the tubular lengths surrounding and lying in close spaced relationship along the length of a fluid supply tube, and when the helical parts of the tubular lengths can be sequentially expanded and contracted.

16. An expansible/contractible means substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.

17. A pivotal connector substantially as hereinbefore described with reference to Figures 4 and 5 of the accompanying drawings.

18. A flexible or bendable member substantially as hereinbefore described with reference to Figures 7 and 8 and Figure 9 of the accompanying drawings.

19. A pump substantially as hereinbefore described with reference to Figure 1~ of the accompanying drawings.