초록 ▼

A tensioner for straps, especially for systems for keeping loads in position, has an anchoring means for the fixed end of the strap and a strap drum worked by a ratchet, the drum then acting as a winch for tensioning the strap. The drum has a locking pawl that may be moved clear of it. The tensionin

A tensioner for straps, especially for systems for keeping loads in position, has an anchoring means for the fixed end of the strap and a strap drum worked by a ratchet, the drum then acting as a winch for tensioning the strap. The drum has a locking pawl that may be moved clear of it. The tensioning ratchet has tooth means on the side of the strap drum so that a driving pawl fixed on the ratchet lever and loaded towards the strap drum by a spring, may be put into driving connection with the tooth means. The ratchet lever further has means limiting the torque that may be transmitted to the tooth means on operation of the ratchet lever by having the driving pawl spring-pre-loaded tangentially in relation to the strap drum. In keeping with another possible design the ratchet is made in two parts that are separated in the length direction of the ratchet lever and are joined together by a mechanism which makes the ratchet lever foldingly give way when the torque acting on the free end of the ratchet lever is greater than a limiting lever. The tensioner may be simply taken to pieces for replacement of its parts.

대표청구항 ▼

1. A strap tensioner, particularly for stowing loads, comprising: a strap (2), anchoring means for a fixed end (13) of said strap (2), a strap drum (28), a ratchet mechanism comprising ratchet wheels (38, 39) placed at each side of said strap drum (28), a drive pawl (58) and a stop pawl (23) coopera

1. A strap tensioner, particularly for stowing loads, comprising: a strap (2), anchoring means for a fixed end (13) of said strap (2), a strap drum (28), a ratchet mechanism comprising ratchet wheels (38, 39) placed at each side of said strap drum (28), a drive pawl (58) and a stop pawl (23) cooperating with said ratchet wheels (38, 39), spring means for urging said drive pawl and said stop pawl in the direction of said ratchet wheels, a ratchet lever (42) which is pivoted about the axis of said strap drum, wherein said drive pawl is movably mounted on said ratchet lever characterized in that said ratchet lever (42) is divided into inner and outer parts (47a, 47b, 48a, 48b) said parts being linked together by an axle (73), wherein each part is connected to a pair of tooth means (79, 80) which are pivotally mounted on said axle, and wherein at least one of said tooth means (79, 80) is axially movable with respect to the other tooth means, said pair of tooth means being tensioned against each other by means of an actuating spring (86), and wherein said strap drum (28) is actuated by said ratchet mechanism in said tensioning direction and is prevented from being overloaded by the pivotal movement of said inner and outer parts about said axle. 2. The tensioner as claimed in claim 1, wherein the tension of the actuating spring (86) is adjustable. 3. The tensioner as claimed in claim 1 or 2, wherein the ratchet lever (42) is composed of two levers (47, 48) arranged parallel to each other at both sides of the strap drum (28), and wherein the axle (73) is extending between the two levers (47, 48). 4. The tensioner as claimed in claim 1, characterized in that the ends of the axle (73) have a polygonal cross-section fitting into respective cutouts of the outer parts (47a, 48a) of the ratchet lever (42), said axle having a part with a cylindrical cross-section, wherein a first tooth means (80) is pivotally mounted upon an extension of said part, and wherein said part is fitted into a respective cutout of an inner part (74b) of the ratchet lever (42), a second tooth means (79) having an inner surface matched with the polygonal cross-section of the axle (73) is slidingly mounted on said part of said axle (73) having a polygonal cross-section, and wherein spring means (86) are provided for tensioning the tooth means (79, 80) against each other. 5. The tensioner as claimed in claim 4, wherein the spring means comprises plate springs (86) mounted on the axle (73). 6. The tensioner as claimed in claim 5, wherein the plate springs (86) are tensioned by a counter element (81) which is slidingly mounted on the axle (73) and is axially adjustable by means of a screw thread (89). 7. The tensioner as claimed in claim 1, wherein an acoustic warning device (94, 95, 96, 107, 108) is actuated by one of the tooth means (79). 8. The tensioner as claimed in claim 7, wherein a tongue (94) is springingly connected with one of the tooth means (79) and is acting against a sounding body (96) placed between the arms (47, 48) of the ratcher lever (42). 9. The tensioner as claimed in claim 8, wherein the sounding body (96) is centered on the axle (73). 10. The tensioner as claimed in claim 1, characterized in that flanks (98') of the tooth means (79, 80) acting in a tensioning direction are steeper than flanks (99') acting in an opposite direction. 11. The tensioner as claimed in claim 1, characterized in that the frame of the anchoring means is formed by a U-shaped piece of sheet metal, two upturned flanges of which constitute arms (7, 8) of said anchoring means. 12. A strap tensioner, particularly for stowing loads, comprising: a strap (2), an anchoring means for a fixed end (13) of said strap (2), a strap drum (28), a ratchet mechanism comprising ratchet wheels (38, 39) placed at each side of said strap drum (28), a drive pawl (58) and a stop pawl (23) cooperating with said ratchet wheels (38, 39), spring means for urging said drive pawl and said stop pawl in the direction of said ratchet wheels, a ratchet lever (42) which is pivoted about the axis of said strap drum, wherein said drive pawl is movably mounted on said ratchet lever characterized in that said drive pawl (58), in addition to being movable in a direction substantially radial to the ratchet wheels (38, 39) is also movable in a direction tangential to the circumference of said ratchet wheels with respect to the ratchet lever, and a tangential spring means (102) for urging said drive pawl (58) in a tangential tensioning direction of the strap drum (28) so that said drive pawl may rotate in said tangential direction against the urging of said tangential spring means so as to prevent overloading of said strap, and wherein said strap drum (28) is actuated by said ratchet mechanism in said tensioning direction. 13. The tensioner as claimed in claim 12, wherein the bias of the tangential spring means (102) is adjustable. 14. The tensioner as claimed in claim 12, characterized in that said drive pawl (58) is guided in a slot of the ratchet lever (47, 48) which is extending substantially parallel to the longitudinal axis of said lever, and wherein the end of the slot adjacent to the strap drum (28) is widened to allow for a certain movement of the drive pawl (58) in a direction tangential to the circumference of the strap drum, such that a spring (102) is inserted between an end of the drive pawl (58) and the ratchet lever (47, 48). 15. The tensioner as claimed in claim 14, wherein the tangential spring means (102) at the side of the ratchet level (47, 48) is held by a counterplate (104) whose position is adjustable by a set screw (106).