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(11) | EP 0 212 888 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Adjustable spanner |
| (57) An adjustable spanner comprises first (2) and second (3) jaw members defining respectively
first and second substantially parallel jaw faces (4, 5) the distance between which
is adjustable by relative sliding of the jaw members. A first wedge face (8) is defined
on the first jaw member (2) and a second wedge face (9) is defined on the second jaw
member. A locking member (10) having wedge faces (11, 12) complementary to the wedge
faces of the jaw members, is slidable to the jaw members to bring the wedge faces
of the locking member (10) into engagement with the wedge faces (8, 9) of the jaw
members (2, 3) to prevent by wedging action the separation of the jaw faces 14, 5). |
[0002] According to one aspect of the present invention there is provided an adjustable spanner comprising: first and second jaw members defining respectively first and second substantially parallel jaw faces, the jaw members being slidable relative to each other to adjust the distance between the jaw faces; a first wedge face defined on the first jaw member; a second wedge face defined on the second jaw member; and a locking member having wedge faces complementary to the wedge faces of the jaw members, the locking member being slidable relative to the jaw members to bring the wedge faces of the locking member into engagement with the wedge faces of the jaw members to prevent by wedging action the separation of the jaw faces.
[0003] The preferred embodiment of the invention comprises three mutually slidable members, and the adjustable spanner can be set to any desired size by sliding the jaw members relative to each other to set the desired spacing between the jaw faces, and sliding the locking member into engagement with the wedge faces of the jaw members to lock the jaw members against separation of the jaw faces.
[0004] In the preferred embodiment of the invention the wedge faces of the jaw members define a small acute angle to each other, and the spanner is adjustable from the widest towards the narrowest setting thereof by applying finger pressure to the locking member thereby causing the locking member to move the second jaw member relative to the first jaw member. Preferably, the second jaw member is spring biased relative to the first jaw member in a direction tending to separate the jaw faces, and the jaw members are therefore movable relative to each other in a direction tending to separate the jaw members by applying finger pressure to the locking member to move it in a sense permitting the spring bias to separate the jaw members.
[0005] The invention will be better understood from the following description of a preferred embodiment thereof, given by way of example only, reference being had to the accompanying drawings wherein:
Figure 1 shows in side and end elevation the components of the adjustable spanner; and
Figure 2 shows the adjustable spanner in an assembled state.
[0006] The adjustable spanner 1 comprises a first jaw member 2 and a second jaw member 3 which define respective substantially parallel jaw faces 4,5. The jaw members 2,3 have respective surfaces 6,7 in sliding engagement whereby the jaw member 3 may be slid along the surface 6 of the jaw member 2 in order to vary the spacing between the jaw faces 4,5.
[0007] A first wedge face 8 is provided on the first jaw member, and a second wedge face 9 is provided on the second jaw member. The wedge faces 8,9 define an included angle of 11.25°. A locking member 10 has internal wedge faces 11,12 which define the same included angle as the wedge faces 8,9. The locking member 10 can accordingly be positioned as illustrated in Figure 2 with the wedge face 11 in full face engagement with the wedge face 8, and the wedge face 12 in full face engagement with the wedge face 9. In this position, the jaw members 2,3 are locked against movement in the direction tending to separate the jaw faces 4,5.
[0008] Finger pressure applied to the locking member 10 generally in the direction of the arrow A will cause the jaw member 3 to slide along the surface 6 of the jaw member 2 to reduce the spacing between the jaw faces 4,5.
[0009] Preferably, the jaw member 3 includes a generally T-shaped slot 13 in which is received a generally T-shaped pin 14 secured to the jaw member 2. A compression spring is installed between the blind end 15 of the slot 13 and the pin 14 to bias the jaw member 3 relative to the jaw member 2 in a direction tending to separate the jaw faces 4,5. Accordingly, finger pressure applied to the locking member 10 in a direction opposite to that of arrow A moves the locking member away from the jaw face 4 and permits the compression spring to move the jaw member 3 in a driection tending to separate the jaw faces 4,5.
1. An adjustable spanner comprising first (2) and second (3) jaw members defining
respectively first and second substantially parallel jaw faces (4,5), characterised
in that the jaw members are slidable relative to each other to adjust the distance
between the jaw £ac/,(4,5), and in that: a first wedge face (8) is defined on the
first jaw member (2); a second wedge face (9) is defined on the second jaw member
(3); and a locking member (10) having wedge faces (11,12) complementary to the wedge
faces of the jaw members, is slidable relative to the jaw members to bring the wedge
faces (11,12) of the locking member into engagement with the wedge faces (8,9) of
the jaw members (2,3) to prevent by wedging action the separation of the jaw faces
(4,5).
2. An adjustable spanner according to claim 1, characterised in that the wedge faces
(8,9) define a small acute angle to each other and the spanner is adjustable from
the widest towards the narrowest setting thereof by applying finger pressure to the
locking member (10) thereby causing the locking member to move the second jaw member
(3) relative to the first jaw member (2) to reduce the spacing of the jaw faces.
3. An adjustable spanner according to claim 2, characterised in that said small acute
angle is substantially 11°.
4. An adjustable spanner according to any preceding claim, characterised in that the
jaw members are in sliding engagement via mutually engaging substantially flat surfaces
(6,7) which are perpendicular to the jaw faces, and wherein the wedge faces (8,9)
of the first and second jaw members subtend substantially equal angles to said flat
surfaces.
5. An adjustable spanner according to any preceding claim, characterised in that the
second jaw member (3) is spring biased relative to the first jaw member (2) in a direction
tending to separate the jaw faces, whereby the jaw members are movable relative to
each other in a direction tending to separate the jaw faces by applying finger pressure
to the locking member (10) to move it in a sense permitting the spring bias to separate
the jaw faces.
6. An adjustable spanner according to claim 5, characterised in that the second jaw
member (3) is retained on the first jaw member (2) by means of a generally T-shaped
pin (14) which is secured to one of the jaw members with the head of the pin captively
retained in a generally T-shaped slot (13) formed in the other of the jaw members.
7. An adjustable spanner according to claim 6, characterised in that the generally
T-shaped pin (14) is secured to the first jaw member (2) and the said spring bias
is provided by a compression spring which is located within said generally T-shaped
slot (13) in the second jaw member (3) and reacts between the generally T-shaped pin
and the second jaw member.
8. An adjustable spanner according to any preceding claim, characterised in that the
locking member (10) is of box-like configuration with first and second opposed side
walls which define the wedge faces of the locking member, and third and fourth side
walls which interconnect the first and second side walls to form a box within which
the jaw members are received.