CN104895883A - Screw nut and screw bolt combination mechanism - Google Patents

Abstract

The present invention provides a clamp, which has a pair of clamp arms, which are hinged at one end and can be connected together by bolts and nuts at the other end. The bolt has a main thread section for tightening a nut to an arm abutment. The bolt also has an unthreaded section of the shank on which the nut is free to move. There are other small segments of thread at the far end of the bolt that hold the nut on the bolt when it disengages from the main threads. The nut can be completely removed from the bolt by engagement with a small thread and twist-twist disengagement. The other end of one arm has a fork into which the crosspiece on the bolt engages, the other arm also has a fork into which the bolt pivots, the upper surface of which provides a Nut holder.

Description

Nut and bolt combination mechanism

technical field

The present invention relates particularly but not exclusively to a nut and bolt combination mechanism for clamps that not only allows quick release but still holds the nut in place.

Background technique

Bioprocessing systems used in the food industry, pharmaceutical industry include clamps for forming connections between other parts of the equipment. These clamps include a pair of generally semicircular jaw arms that are hinged at one end and connectable at the other end with bolts and nuts. The clamp arms have inwardly facing tapered grooves to enable sealing engagement of the two flange connections typically with a gasket therebetween. The bolt has a cross head for engaging in the fork of one of the clamp arms. The other clamp arm also has a fork for receiving the bolt and providing a seat for the nut. The standoff and nut have complementary tapered configurations to prevent the forks from spreading when the nut is tightened. Typically, the fork of the first clamp arm also has a ledge remote from the clamp arm to allow limited pivotal movement of the bolt from its engaged but not connected position.

To use this clamp, the operator must loosen the nut far enough along the bolt to allow the nut and bolt combination to swing out of the fork of each clamp arm, thereby allowing the clamp to open at its hinge. Then, the clamp is seated around the pair of flanges, the bolt is re-seat between the prongs and the nut is re-tightened. The fork must be long enough to provide a seat for the nut, so the nut has to travel a distance along the bolt to clear the end of the fork when turning in or out of the fork. When this process is repeated for many fixtures, the opening and closing of the nuts on the bolts can be time consuming and can cause repetitive strain injuries.

Contents of the invention

It is an object of the present invention to provide an improved, more rapid release nut and bolt combination mechanism.

According to the present invention, there is provided a nut and bolt combination mechanism for clamps and the like, comprising:

Nuts with internal threads;

Bolts with:

A small mating thread at the distal end of the bolt shank for retaining the nut;

the main mating thread section along its shank to enable the nut to be tightened to the standoff;

• An unthreaded section of the rod separating the minor thread and the main thread section, enabling the nut to move freely along the unthreaded section of the shank.

Thus, the nut can be held on the bolt by the small thread and can move freely along the unthreaded shank. Subsequently, the nut is screwed onto the support with the main thread by turning the bolt a few turns. To quickly release the clamp, the nut is turned a few turns to disengage the nut from the main threads, and the nut can then be moved away from the seat along the unthreaded section of the rod. However, the nut is held on the rod by a small thread, although the nut can still be removed by further screwing of the nut.

Preferably, the nut is closed at its distal end and has a short internal thread at its proximal end.

The main thread may suitably be a double start thread in order to obtain a connection with the nut thread more quickly.

According to a second aspect of the present invention, there is provided a clamp comprising a pair of clamp arms hinged at one end and connectable at the other end by the nut and bolt combination mechanism according to the first aspect.

Preferably the bolt includes a ledge for engaging within the fork of one of the pair of clamp arms.

The other clamp arm will also typically have a fork for receiving the bolt and providing a standoff.

Advantageously, the nut and seat are provided with complementary formations for fitting the nut to the seat. Typically, the seat will be provided with protrusions, while the nut will have complementary recesses.

Description of drawings

In order to facilitate the understanding of the present invention, specific embodiments thereof will be further described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is the front view of bolt and nut according to the present invention;

Figure 2 is a cross-sectional view of a clamp comprising a bolt and a nut of the present invention; and

3 is a cross-sectional view of the clamp of FIG. 2 with the nut loosened but retained on the bolt.

Detailed ways

Referring to the accompanying drawings, there is provided a connection mechanism for clamps and the like comprising a bolt 1 having a main thread 2 on which a nut 4 can be engaged for screwing onto a standoff and a stem capable of retaining the nut on the bolt 1 Retaining thread 6 on 8. Between the two threads 2, 6 is an unthreaded section 10 of the rod 8, along which the nut is free to move to allow the nut to leave the main threaded section.

An example of a device incorporating the invention will now be described.

2 and 3 illustrate a clamp 10' comprising a pair of generally semicircular clamp arms 12,14. These jaw arms have tapered grooves 16 extending about their insides for engaging a flange-to-flange, not shown, seal of a pair of flanged joints to maintain the pair of joints in sealed relation to each other.

The first ends 18, 20 of the clamp arms are held together by a pin 22, allowing the clamp arms to pivot relative to each other for positioning about the connection. Alternatively, other methods of attaching the clamp arms may be used.

The second ends of the clip arms are held together by the arrangement of the nuts 4, 104 and the bolts 1, 101 of the present invention.

One of the clip arms 12 has a fork 24 defined by two lugs 26 . Each lug has a suspended groove, and the crosshead 29 of the bolt 1, 101 snaps into the suspended groove. Crosspiece 28 joins lug 26 at the clamp arm remote from lug 26 so that the bolt is limited to angular displacement about groove 30 defined by the clamp arm, lug and crosspiece. The crosspiece also stabilizes the lug against relative displacement under force when the nut is tightened.

The other clamp arm 14 has a partially tapered formation 32 on a lug 34 that defines a prong 36 similar to the prong 24 on the first clamp arm 12 . The nut 4 , 104 has complementary conical grooves 38 . Engagement of the formation 32 within the groove 38 prevents the lugs from being forced apart as the nut is tightened. When the nut is tightened on the seat 40 formed by the two lugs 34, the mutual approach of the two clamping arms is limited by the projections 42 on the lugs 34 to avoid overtightening.

According to the invention, the bolt 1 , 101 has a main thread 2 , 102 which extends from above the crosshead 29 to just above the seat 40 . The unthreaded section 10, 110 of the rod 8, 108 then extends a small distance to provide sufficient spacing between the lug 34 and the nut 4, 104, enough to allow the bolt 1, 101 to pivot out of the fork, loosen fixture. The unthreaded section has a diameter small enough that the nut can move freely thereon. A short length of second thread 6,106 is provided at the distal end of rod 8,108. This serves to retain the nut on the rod when the nut is disengaged from the main thread 2 , 102 and is free to move on the unthreaded section 10 , 110 . The nut 4, 104 can be removed from the rod by engaging and rotating the internal thread 5, 105 of the nut 4, 104 with the second thread 6, 106.

In order to facilitate the connection between the main thread 2 and the internal thread 5 on the nut, the main thread is configured as a double-start thread. However, single-start or even triple-start threads may also be used.

For the clamp shown in this embodiment, the nut 4 is a closed wing nut 104 . It generally provides a short length of mating internal thread at its open end. The inner upper section of the nut is unthreaded and of sufficient diameter to allow free movement of the retaining threaded section 6 of the bolt 1 . The nut will also have sufficient length to enclose the bolt when tightened onto the standoff. This provides a bolt that is large enough to handle easily even on small fixtures.

The invention is not intended to be limited to the details of the above-described embodiments. For example, the nut and bolt arrangement of this connection can be used with any type of clamp, including spring clamps.

Claims (8)

1. A nut and bolt combination mechanism for clamps and the like, comprising: a nut with an internal thread; and Bolts with: A small section of mating thread at its distal end for retaining the nut; the main mating threaded section along its body for enabling the nut to be tightened to the seat; and the unthreaded section of the rod separating the minor thread from the main thread for enabling the nut to be threaded along The unthreaded section of the rod moves freely. 2. The nut and bolt combination of claim 1, wherein the nut is closed at its distal end and has a short internal thread at its proximal end. 3. The nut and bolt combination mechanism according to claim 1 or 2, wherein the main thread is a double-start thread so as to obtain a connection with the thread on the nut more quickly. 4. A clamp comprising a pair of clamp arms, which are hinged at one end and can be connected together at the other end by a nut and bolt combination mechanism as claimed in claim 1. 5. The clamp of claim 4, wherein said bolt includes a ledge for engaging in a fork in one of said clamp arms. 6. A clamp according to claim 4 or 5, wherein the other of said clamp arms has a fork for receiving the bolt and providing a seat. 7. Clamp according to claim 4, 5 or 6, characterized in that said nut and said support are provided with complementary structures for assembling the nut on the support. 8. The clamp according to claim 7, wherein the support has a plurality of protrusions, and the nut has a plurality of complementary grooves.