GB2453608A

GB2453608A - Clamp hinge which prevents unwanted rotation

Info

Publication number: GB2453608A
Application number: GB0806433A
Authority: GB
Inventors: Roy Peter Maunder
Original assignee: Bio Pure Technology Ltd
Current assignee: Bio Pure Technology Ltd
Priority date: 2007-10-12
Filing date: 2008-04-09
Publication date: 2009-04-15
Anticipated expiration: 2028-04-09
Also published as: GB0806584D0; GB0719972D0; GB2453608B; US7677612B2; GB0806433D0; EP2048424B1; ES2712711T3; EP2048424A1; HUE042104T2; US20090096210A1; PL2048424T3; DK2048424T3

Abstract

A two part annular clamp for connecting flanged tubes comprises a pair of tangs 2, 4 having a tampered groove around their insides to engage the flanges. One of the tangs 2 is provided with a pivotally connected screw 46, which passes through an aperture 54 in the other tang 4. A nut 44 is attached to the screw 46 to hold the tangs 2, 4 in position. To prevent rotation of the tang 4 about the screw 46, the lower shaft of the screw 53 is provided in a square shape, and the aperture 54 in the tang is also provided with a mating square shape.

Description

CLAMP

The present invention relates to clamps, particularly though not exclusively for connecting flanged tubes for use in the pharmaceutical, food and related industries.

In my earlier patent, GB236 1753, I describe a clamp for connecting flanged tubes. This clamp is very successful for connecting flanged tubes of up to and including approximately four inches in diameter. However for clamps of a larger size, I find that the hinge starts to fail on prolonged use.

While using the same screw and nut arrangement at both sides of the clamp provides a secure clamp, such a clamp is awkward and difficult to use and cannot be used one handed.

The object of the present invention is to provide an improved joint for a clamp orthe like.

According to the invention there is provided a joint for a clamp or the like, having a pair of tangs, the joint including a screw pivotally connected to a first tang, and having a section of non-circular shaped shaft extending from the pivotal connection, the second tang having a complementary aperture for receiving the screw, the fit between the shaft and the aperture preventing significant rotation of the second tang around the screw.

Preferably, the shape of the shaft is essentially square, with the aperture in the tang also being square. Alternatively, the shaft may be triangular, pentagonal, hexagonal or any other non-curricular shape.

The joint further includes a nut for connection to the thread of the screw to hold the tangs in position.

Preferably the second tang may have a projection at least partially surrounding its aperture with the nut having a complementary indentation. Typically the projection and indentation will be substantially conical.

Advantageously the second tang may be provided with at least one projection to mate on the first tang, to prevent over-tightening of the clamp tangs.

To help understanding of the invention, a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a side view of a clamp according to the present invention in the closed position; and Figure 2 is a side view of the clamp of Figure in the an open position.

Referring to Figures 1 and 2, the clamp thereshown is for clamping flanged tubes, particularly for use in the pharmaceutical and food industries.

The clamp comprises a pair of substantially semi-circular tangs 2, 4. The tangs have a tapered 6 groove running around the inside of them, to engage the flanges of a paid of flanged tubes with a seal therebetween, not shown, holding the tubes in sealing relationship with each other.

At one side, the tangs 2, 4 are held together with a nut 10 and screw 12 as described in my earlier patent GB 2361753. One tang 2 has a clevis 20 defined by two lugs 22. Each had an overhung recess 24 into which the crosshead 26 of the screw 12 clips. A cross-bar 28 connects the lugs remote from their tang, whereby the screw is limited in its angular displacement about the recess. The crossbar also stabilises the lugs against relative displacement under load when the nut is tightened.

The other tang 4 has a part conical formation 30 on lugs 32 defining a clevis 34. The nut 10 has a complementary conical recess 36. Engagement of the formation in the recess 36 restrains the lugs from separating under load as the nut is tightened. Mutual approach of the tangs is limited by projections 38 on the lugs 32 towards the lugs 22 to avoid over tightening.

The other ends 40, 42 of the tangs 2, 4 are also held together with a nut 44 and screw 46. The screw 46 is held captive between a pair of lugs 48 defining a clevis 50 in one of tangs 2. The screw 46 is provided with a ring 52 which fits in the clevis 50 held in position by a pin 51. The screw is provided with a section of lower shaft 53 of square cross-section. The other tang 4 is provided with. square aperture 54 for receiving the screw 46. Thus use of the square shaft 53 and square aperture 54, prevents significant rotational movement of the tangs 2, 4 rendering the clamp stronger and easier to use. It is not essential that the shaft and aperture are square, they could be triangular, hexagonal or any non-circular shape.

The nut 44 is provided with an internal thread for engagement with the screw 46. This enables tightening and loosening of the nut on the screw and thus limited movement between the two tangs.

The aperture 54 is surrounded by a conical projection 68, with a complementary conical indentation 70 in the nut 44 centring the nut on the tang and stabilising the aperture. The tang 4 is also provided in projections 72 to prevent over-tightening of the nut 44 onto the screw 46.

The invention is not intended to be restricted to the details of the above described embodiment. For instance, this connected nut and screw arrangement can be used on any form of clamp, including a pinch clamp.

Claims

CLAIMS: 1. A joint for a clamp or the like, having a pair of tangs, the joint including a screw pivotally connected to a first tang, and having a section of non-circular shaped shaft extending from the pivotal connection, the second tang having a complementary aperture for receiving the section of shaft, thus prevent significant rotation of the second tang around the screw.
2. A joint as claimed in claim 1, wherein the shape of the section of shaft is essentially square, with the aperture in the tang also being square.
3. A joint as claimed in claim 1, wherein the shape of the shaft is triangular, with the io aperture in the tang also being square.
4. A joint as claimed in claim 1, claim 2 or claim 3, further including a nut for connection to the thread of the screw.
5. A joint as claimed in claim 4, wherein the second tang has a projection at least partially surrounding its aperture and the nut has a complementary indentation.
6. A joint as claimed in claim 5, wherein the projection and indentation are substantially conical.
7. A joint as claimed in any preceding claim, wherein the second tang is provided with at least one projections to mate on the other tang, to prevent over-tightening of the clamp tangs.
8. A clamp substantially as hereinbefore described with reference to Figures 1 and 2 of the drawings.