WO1999009325A1

WO1999009325A1 - Holding clamp

Info

Publication number: WO1999009325A1
Application number: PCT/AU1998/000680
Authority: WO
Inventors: John Isherwood
Original assignee: Multiplan Company Pty. Ltd.; Avania Management (Nsw) Pty. Ltd.
Priority date: 1997-08-15
Filing date: 1998-08-17
Publication date: 1999-02-25

Abstract

A clamp (1) for holding sheet material such as plans and laminates and the like, comprising two extruded clamping members (2 and 9) which are hingedly connected together. Each clamping member (2 and 9) has hinge section (11 and 5) which slideably engage together to form the hinge (14). A theaded elongated member (18) extends through a hole (19) in the base (3) of one of the clamping members (2), and engages with the projection (13), whereby when the wingnut (22) which engages on the threaded elongated member (18) above the base (3) of the clamping member (2) is rotated the clamping members (2 and 9) pivot around the hinge (14).

Description

Holding Clamp

The present invention relates to a holding clamp for elongated sheets,

such as architectural and engineering plans. In particularly the invention relates

to a holding clamp capable of holding any required number of sheets, which

clamp is adapted to be releasably held in a rack.

It is necessary to hold and store elongated sheets such as laminates,

paper, film or plan without crimping or creasing of the sheet. Some prior art

holding clamps utilise a single u-shaped (in cross section) clamping means,

having a springs to urge the arms of the clamp apart. Thus when the operating

screws are tightened the screws overcome the springs and allow the natural

resilience of the clamp to close the clamp. Others, such as the clamp shown in

Australian patent no. 581619 have a two part construction utilising two L-

shaped sections, one sitting within the other, again having a spring to urge the

clamping arms apart, and locking screws to overcome the spring and pull the

clamping arms towards each other.

These systems have disadvantages in that they usually require

considerable force to securely clamp the sheets, as there is no effective hinging

point. The present invention seeks to overcome these disadvantages by

providing a clamp for sheets of materials, comprising :

a first clamping member, being of constant cross section, and having a

base, a clamping arm extending substantially normally from said base and

terminating in a free edge, and a first hinge means located on said base;

a second clamping member being of constant cross section and having a

second hinge means, a clamping arm terminating in a free edge, a second

hinge means, and a projection;

whereby the first and second hinge means slideably engage each other

to form a hinge about which the clamping arms of the first and second clamping

members pivot; and

operating means which projects through the base of the first clamping

member and engages with the projection of said second clamping member,

whereby the operating means opens and closes the clamp by pivoting said

clamping arms around the hinge.

In a further form the invention comprises a clamp for sheets of materials,

comprising : a first clamping member, being of constant cross section, and having a

base, a first clamping arm extending substantially normally from said base and

terminating in a free edge, and a first hinge means located on said base;

a second clamping member being of constant cross section and having a

second hinge means, a second clamping arm terminating in a free edge, and a

projection;

whereby the first and second hinge means slideably engage each other

to form a hinge about which the clamping arms of the first and second clamping

members pivot;

at least one operating means which projects through the base of the first

clamping member and engages with the projection of said second clamping

member, whereby the operating means closes the clamp by pivoting said

clamping arms around the hinge, and

a spring means associated with at least one of said operating means and

bearing against each of said clamping arms to urge said clamping arms to pivot

away from each other. The present invention will now be described by way of example with

reference to the accompanying drawings in which:

Figure 1 illustrates a cut out view of a portion of a clamp according to an

embodiment of the present invention in its closed position;

Figure 2 illustrates a cross sectional view through the clamp as shown in

figure 1 ;

Figure 3 shows the clamp illustrated in figure 1 in an open position;

Figure 4 illustrates a cut out view of a portion of a clamp according to

another embodiment of the present invention in its closed position;

Figure 5 illustrates a cross sectional view through the clamp as shown in

figure 4; and

Figure 6 shows the clamp illustrated in figure 4 in an open position.

In the drawings similar components will have the same number in each

of the embodiments. The clamp (1 ) as shown in figures 1 - 3 of the accompanying drawings

comprises two extruded clamping members (2 & 9).

The first extruded clamping member (2) comprises a base (3), with a

clamping arm (4) extending substantially normal to the base (3) on one side of

the base (3) and terminating in a free edge (12). A recess (5) is formed by a

substantially c-shaped projection (6), located on the base (3) opposite the

clamping arm (4), and extending on the same side of the base (3) as the

clamping arm (4). Two re-entrant shoulders (7) extend from the other side of

the base (3) to form a channel (8) on the back of the clamp (1 ).

The second extruded clamping member (9) comprises a clamping arm

(10) having a bulbous shaped rail (11 ) along one edge, and a free edge (25) on

the other edge. The bulbous rail (11 ) slides along the recess (5) forming a hinge

(14). A projection (13) extends from the clamping arm (10), and is in the form of

a yoke or Y-shaped in cross section, having an upper arm (15) and a lower arm

(16).

A recess (17) is cut into the upper arm (15) of the projection (13). A bolt

(18) extends upwardly through the recess (17) through a hole (19) in the base

(3) of the clamping member (2). The T-shaped head (20) of the bolt (18) is held in the channel (21 ) of the yoke shaped projection (13). The threaded portion

(23) of the wing nut (22) engages the threaded shaft (26) of the bolt (18). The

wingnut (22) has an annular groove (27) which is engaged by the re-entrant

shoulders (7). Thus by rotation of the wingnut (22) the bolt (18) is forced to

move along the bore (24) in the wingnut (22).

Therefore, as shown in figures 1 & 2, by tightening the wingnut (22) the

bolt (18) moves into the bore (24) and the T-shaped head (20) of the bolt (18)

bears against the upper arm (15) of the yoke shaped projection (13), pivoting

the clamping arm (10) around the hinge (14) and forcing the free edges (12 &

25) towards each other, to clamp a sheet therebetween. By rotating the wingnut

(22) in the other direction the bolt (18) moves out of the bore (24) and bears

against the lower arm (16) of the yoke shaped projection (13 ) pivoting the

clamping arm (10) around the hinge (14) and forcing the free edges (12 & 25)

away from each other, opening the clamp (1 ), as shown in figure 3.

The clamp (1 ) according to another embodiment is shown in figures 4-6

of the accompanying drawings. The clamp (1 ) is similar, in construction and

operation, to that of the clamp shown in figures 1-3, except that it uses a spring

(29) to open the clamp (1 ) Further the yoke shaped projection (13) is replaced with the S-shaped

arm (28) having a recess (17) cut therein. A bolt (18) extends upwardly

through the recess (17) through a hole (19) in the base (3) of the clamping

member (2). The T-shaped head (20) of the bolt (18) abuts against the spring

(29) which in turn abuts against the underside of the S-shaped arm (28). The

spring (29) has a hole (30) through which extends the threaded portion (26) of

the bolt (18), with the two arms (31 & 32) of the spring (29) extending outwardly

to bear against the two clamping arms (4 & 10) to bias them into an open

position.

The threaded portion (23) of the wing nut (22) engages the threaded

shaft (26) of the bolt (18). The wingnut (22) has an annular groove (27) which is

engaged by the re-entrant shoulders (7). Thus by rotation of the wingnut (22)

the bolt (18) is forced to move along the bore (24) in the wingnut (22).

Therefore, as shown in figures 4 & 5, by tightening the wingnut (22) the

bolt (18) moves into the bore (24) and the T-shaped head (20) of the bolt (18)

bears against the S-shaped arm (28), pivoting the clamping arm (10) around

the hinge (14), and forcing the free edges (12 & 25) towards each other,

against the biasing force of the spring (29), to clamp a sheet therebetween. By

rotating the wingnut (22) in the other direction the bolt (18) moves out of the

bore (24) relieving the pressure of the T-shaped head (20) on the S-shaped projection (28) and allow the two arms (31 & 32) of the spring (29) to force the

two clamping arms (4 & 10) away from each other, pivoting the clamping arm

(10) around the hinge (14) and opening the clamp (1 ), as shown in figure 6.

Any desirable number of wingnut operating bolts can be used along the

length of the clamp.

Stops (not shown ) can be moveably located in the channel (8) to assist

in the holding of the clamp (1 ) in suitable racks. Further the handle can also be

releasable connected to the channel (8), and can also incorporate a hook for

holding in a suitable rack.

Instead of the T-shaped bolt (18) and arm (13 & 28) arrangement, any

suitable connection between the bolt and the projection could be used; for

example, the head of the bolt could have a hole therethrough in which the

projection (13) engages. Similarly the male and female components of the

hinge (14) could be reversed. The clamp could be made from any suitable

material such as metal or plastics.

It should be obvious to people skilled in the art that modification and

alterations could be made to the above described embodiment without

departing from the scope and spirit of the invention

Claims

The claims are:

1. A clamp for sheets of materials, comprising :

a first clamping member, being of constant cross section, and having a

base, a clamping arm extending substantially normally from said base and

terminating in a free edge, and a first hinge means located on said base;

a second clamping member being of constant cross section and having a

second hinge means, a clamping arm terminating in a free edge, a second

hinge means, and a projection;

whereby the first and second hinge means slideably engage each other

to form a hinge about which the clamping arms of the first and second clamping

members pivot; and

operating means which projects through the base of the first clamping

member and engages with the projection of said second clamping member,

whereby the operating means opens and closes the clamp by pivoting said

clamping arms around the hinge.

2. A clamp according to claim 1 wherein said operating means

comprises a threaded shank which is interacts with said projection, and a user engaging means having a threaded bore into which is engaged the threaded

shank, such that when said user engaging means is rotated the threaded shank

is moved along said threaded bore pivoting said clamping arms around the

hinge.

3. A clamp according to claim 2 wherein said user engaging means

is held in a channel located on said first clamping member on the side of said

base remote from said clamping arm and said hinge means.

4. A clamp according to any one of the preceding claims wherein the

projection is a yoke shape in cross section, and the operating means has a

shank which extends through a hole in one arm of the yoke shaped projection,

and has a t-shaped headed bolt which lies between the arms of the yoke

shaped projection.

5. A clamp for sheets of materials, comprising a first clamping member, being of constant cross section, and having a

base, a first clamping arm extending substantially normally from said base and

terminating in a free edge, and a first hinge means located on said base;

a second clamping member being of constant cross section and having a

second hinge means, a second clamping arm terminating in a free edge, and a

projection;

whereby the first and second hinge means slideably engage each other

to form a hinge about which the clamping arms of the first and second clamping

members pivot;

at least one operating means which projects through the base of the first

clamping member and engages with the projection of said second clamping

member, whereby the operating means closes the clamp by pivoting said

clamping arms around the hinge, and

a spring means associated with at least one of said clamping members

and bearing against each of said clamping arms to urge said clamping arms to

pivot away from each other.

6. A clamp according to claim 51 wherein said operating means

comprises a threaded shank which is interacts with said projection, and a user

engaging means having a threaded bore into which is engaged the threaded

shank, such that when said user engaging means is rotated the threaded shank

is moved along said threaded bore pivoting said clamping arms around the

hinge.

7. A clamp according to claim 6 wherein said user engaging means

is held in a channel located on said first clamping member on the side of said

base remote from said clamping arm and said hinge means.

8. A clamp according to any one of claims 5 to 7, wherein said

projection and said spring each have an opening through which extends a

shank of the operating means, which has a head which holds said spring

against said projection.

9. A clamp for sheets of materials substantially as hereinbefore

described with reference to the accompanying drawings.