Patent EA-002714-B1 (EA)
Title: Clamping tool
Inventor: KOFOD KARSTEN BENT
IPC: B25B5/16
Filed: 2000-02-17
Abstract: 1. A clamping tool (1) for clamping a workpiece (2) to a support (3) by means of a bar system (8) constructed of a number of mutually pivotal bars and comprising an activation bar (10) for at operation making the bars pivot mutually between an initial position and a locking position, a clamping bar (9) having at least one thrust shoe (19;20) for pressing against the workpiece in the locking position of the bar system, and a base (6) for mounting the bar system on the support, characterised in that the bar system furthermore comprises at least two toggle joints (13;16), at least two of these toggle joints (13;16) being arranged to simultaneously or almost simultaneously assume their dead point position when the bar system at activation is taken from the initial position to the locking position, and that said two toggle joints (13;16) form an angle with each other in the dead point positions. 2. A clamping tool (1) according to claim 1, characterised in that the two joints of each toggle joint (13;16) together form an angle that points its point in the opposite direction of the at least one clamp shoe (19;20) in the initial position of the bar system. 3. A clamping tool (1) according to claim 1 or 2, characterised in that the two joints (14;15) and (17;18) respectively of each toggle joint (13;16) together form an angle that point its point in a direction towards the at least one clamp shoe (19;20) in the locking position of the bar system. 4. A clamping tool (1) according to claim 3, characterised in that the angle that the two joints (14;15) and (17;18) respectively of each toggle joint (13;16) form together in the locking position of the bar system is between 175 degree  and 180 degree , preferably between 177 degree  and 180 degree , and especially between 178 degree  and 180 degree . 5. A clamping tool (1) according to any of the claims 1 - 4, characterised in that the bar system comprises a first swivel connection (21) for pivotally journaling one end of the activation bar (10) in the base (6) while the other end of the activation bar (10) is free and serves as handle (11) for the clamping tool (1); a rocking bar (12) which at one end is pivotally journaled in the base (6) via a second swivel connection (22) which is nearer the at least one clamp shoe (19;20) than the first swivel connection (21) and at the other end is pivotally journaled in the clamping bar (9) via a third swivel connection (23); a first toggle joint (13) having a first joint (14) which at one end is pivotally journaled in the clamping bar (9) via a fourth swivel connection (24) which is farther from the at least one clamp shoe (19;20) than the third swivel connection (23) and at the other end is pivotally journaled in the activation bar (10) via a fifth swivel connection (25), and a second joint (15) consisting of the part of the activation bar (10) that is extending from the fifth to the first swivel connection (25;21); and a second toggle joint (16) having a first joint (17) which at one end is pivotally journaled in the rocking bar (12) and/or clamping bar (9) via a sixth swivel connection (26) and at the other end is pivotally journaled in the activation bar (10) via a seventh swivel connection (27) which in the locking position of the clamping tool is nearer the at least one clamp shoe than the first and the fifth swivel connection (21;25), and a second joint (18) consisting of the part of the activation bar (10) that is extending between the seventh and the first swivel connection (27;21). 6. A clamping tool (1) according to claim 5, characterised in that the third and the sixth swivel connection (23;26) coincide. 7. A clamping tool (1) according to claim 5 or 6, characterised in that the sixth swivel connection (26) is placed on the rocking bar (12) between the second and the third swivel connection (22;23). 8. A clamping tool (1) according to any of the claims 1 - 7, characterised in that the first and the second toggle joint (13;16) pass the dead point positions simultaneously when the bar system is taken from its initial position to its locking position. 9. A clamping tool (1) according to any of the claims 1 - 7, characterised in that the first and the second toggle joint (13;16) do not pass the dead point positions simultaneously when the bar system is taken from its initial position to its locking position. 10. A clamping tool (1) according to any of the claims 1 - 9, characterised in that the first joint (14;17) of the first and second toggle joint (13;16) respectively is shaped as a U having a bottom and two sides.