IE20010838A1

IE20010838A1 - One way drive

Info

Publication number: IE20010838A1
Application number: IE20010838A
Authority: IE
Inventors: Seamus Duffy
Original assignee: Seamus Duffy
Priority date: 2001-09-18
Filing date: 2001-09-18
Publication date: 2003-03-19

Abstract

A head portion (2) includes a flexible ring (2a) and circular drive (4) when a torque is applied in the drive direction (D) to the handle portion (3) the handle portion (3) pivots around the axis pin (6) the resultant force acts through a pawl (3c) incorporated on the levered end (3b) of the handle portion (3) onto a tooth (2c) on the free end (2e) of the flexible ring (2a) closing and locking the flexible ring (2a) on the circular drive (4). When operated in the reverse drive direction r the friction between the circular drive (4) and the flexible ring (2a) causes the resilient bias of the flexible ring (2a) to be overcome just enough to allow rotation relative to the circular drive (4) thereby substantially reducing the amount of play between the drive (D) and reverse r operations whilst substantially increasing the amount of torque which can be transmitted via the circular drive (4) to operate a known socket or drive bit and thereby a known fastener. <Figure 1>

Description

INSTANT ONE WAY DRIVE.

The present invention relates to a one way locking device in particular ratchetbars. A ratchet bar is a tool for applying torque normally via an attached square drive and appropriate socket to a nut, bolt or screw (hereinafter referred to as a fastener) for the purpose of tightening or slackening the fastener. The ratchet bar allows motion between the ratchet bar and the socket in one direction only. The motion between the ratchet bar and the socket can be prevented by a set of angular teeth, between which a pawl drops creating a locking motion in one direction only and free movement in the opposite direction. This operation of the socket and fastener via the ratchet bar is much more convenient in restrictive situations than the use of a fixed bar operated socket as there is seldom a requirement to remove and re attach the socket operating the fastener.

Variations of the ratchet bar are exhaustive. Most mechanisms have more and more locking teeth etc. to allow a smaller angle between drive, re-position and drive have resulted in mechanisms that whilst the angle between drive and reposition has been substantially reduced so has the amount of torque that can be safely applied to the ratchet bar without failure. The increasing intricacies of the ratchet mechanisms have resulted in devices intolerant to dirt or corrosion.

It is an object of the prepent invention to provide an improved one way locking device in particular an instant one way drive version ofacopve oPBmpueucRSPECJKw ! UNDER SECTION 28 AND RULE 23 JNLNoJ.3,££____OF..QMS I INT CL ___2 ¢0 V®®'9 8 bar, allowing the ratchet bar to grip instantly when used in the drive direction, yet freewheel easily in the re-position direction. When torque is applied to the ratchet bar the action of the mechanism is to increase the locking action the more torque is applied.

EO 1 085 8 In accordance with the present invention there is provided an instant one way drive having a head portion adapted to engage and apply torque to a known socket or drive bit in order to operate a known fastener said head portion including a flexible ring having an inner working surface for engaging the circular drive such that, when a torque is applied to said head portion in a predetermined direction, said flexible ring closes and grips the circular drive. The circular drive has a preferably square middle section for the engagement of a known socket square drive and thereby a known socket and fastener. The flexible ring and handle portion are rotateably held together by an axis pin. The free end of the flexible ring preferably incorporating a tooth, which engages a pawl, incorporated in the handle portion.

As the handle portion is rotated in the drive direction it rotates around the axis pin, the pawl acting on the tooth on the free end of the flexible ring dosing the flexible ring around the drcular drive locking the flexible ring and circular drive together enabling the fastener to be operated via the square drive and appropriate socket or known drive bit.

Preferably the inside circular gripping surface of the flexible ring is a fine smooth finish.

Preferably the gripping surface of the circular drive is a fine smooth finish.

Preferably the flexible ring has a sprung grip on the circular drive.

EO 10858 Preferably the circular drive portion can rotate within the flexible ring in the reverse direction.

Preferable the ‘play1 between tooth on the free end of the flexible ring and the pawl on the torque handle is kept to a minimum to prevent unnecessary movement in the transition between re-position/reverse and drive functions of the instant one way drive.

Preferably the centre line between the tooth on the free end of the flexible ring and the pawl on the levered end of the handle portion is parallel to the axis pin.

Preferably the circular drive portion is retained within the flexible ring portion by known means such as a retaining screw or circlips.

Preferably the axis pin is retained by known means within the flexible ring portion whilst allowing the torque handle to pivot freely in relation to the flexible ring portion without under play.

In an alternative embodiment, tiie inner surface of the circular drive portion is generally polygonal in order to usefully engage hexagonal headed fasteners in order to tighten or slacken Ihe same.

In further embodiment the circular drive portion, flexible ring portion plus axis pin and pivotal pawl are part of a one directional drive system whereas the circular drive portion preferably forms part of an output drive shaft. The torque handle being replaced by an actuator pivoting around the aids pin operating the pawl on to the tooth on the free end of the flexible ring enabling an input force upon the actuator to be converted into an output force in one direction only at the output drive shaft.

Preferably a known spring mechanism repositions the flexible ring portion and actuator during the non-drive reverse/repositioning sequence.

Embodiments of the present invention will now be described by way of example only. With reference to the accompanying drawing in which: Fig i Is a perspective view of the dismantled instant one way drive. Fig 2 Is a perspective view of the assembled instant one way drive Fig 3 Is a front elevation view of the instant one way drive in drive mode. Fig 4a, b, c, Is a front side and to elevation view of the instant one way drive. Fig 5 Is a front elevation view of the zero degree ratchet in the reverse or repositioning mode. Fig 6 Shows in perspective the zero degree ratchet where the circular drive portion had a hexagonal inner surface for direct application to hexagonal headed fasteners, ΙΕΟ 1083 8 The embodiments of the present invention will now be described with reference to the drawings. In the various embodiments and corresponding drawings like reference numerals will be used to indicate like features.

Referring now to Figure 1 of the drawings- An instant one way drive (1) made in accordance to the invention includes a head portion (2) adapted to engage and apply torque to a known socket or drive bit in order to operate a known fastener. When the handle portion (3) is operated in a predetermined drive (D) direction yet the circular drive (4) substantially freewheels when the handle portion (3) is operated in the re-position or reverse ® direction the head portion (2) includes a flexible ring (2a) having an inner surface (2b) for the engagement of the circular drive (4) such that when torque is applied in the drive direction (D) to the lever end (3a) of the handle portion (3) which is arranged to pivot around the axis pin(6) via pivot points (3d) on the handle portion (3) and (2d) on the flexible ring (2a) the axis pin (6) also mechanically holds the handle portion (3) and the head portion (2) together. The torque arm force applied to the lever end (3a) of the handle portion (3) is substantially increased by the mechanical advantage of the lever action and the resultant force acts on a pawl (3c) incorporated in the levered end (3b) of the handle portion (3). The pawl (3c) acts on a tooth or suitable projection (2c) incorporated in the free end (2e) cf the flexible ring (2a) closing and gripping the inner surface (2b) of toe flexible ring (2a) on to toe outer surface (4a) of toe circular drive (4) serving to lock the flexible ring (2a) and toe circular drive (4) together. The torque applied to the handle portion (3) can then be usefully ΙΕΟ 1 88 5 β used to operate a known socket or drive bit through a square recess (4b) and complementary socket square drive (5) to operate a known fastener. To usefully prevent undue slippage the flexible ring (2a) has a resilient bias upon the circular drive (4). This is substantially decreased when the handle portion (3) is operated in the reverse drive direction ®. The degree of friction between the flexible ring inner surface (2b) and circular drive outer surface (4a) causing the flexible ring (2) to open just enough to allow the flexible ring (2) to rotate relative to the circular drive (4).

Claims

CLAIMS.

1. A ratchet like mechanism or one way drive system such as a ratchet bar or mechanism to drive with considerable torque in one direction and to be conveniently reversed or repositioned on the opposite direction. In order to reduce the amount of play between the drive and reverse operations the amount of teeth used in these mechanisms has been substantially increased whilst the amount of torque they are capable of transmitting has reduced. The present invention is arranged to substantially reduce the amount of play between the drive (D) and reverse ® operations whilst being capable of transmitting more torque. The instant one way drive (1) comprises a head portion (2) adapted to engage and apply torque to a known socket or drive bit in order to operate a known fastener, When the handle portion (3) is operated in a predetermined drive (D) direction yet the circular drive ( 4) substantially freewheels when the handle portion (3) is operated in the reverse ® direction Characterised in the said head portion (2) includes a flexible ring (2a) having inner surface (2b) for the engagement of the circular drive (4) such that when torque is applied in the drive direction (D) to the lever end (3a) of the handle portion (3) which is arranged to pivot around the axis pin (6) via pivot points (3d) on the handle portion (3) and (2d) on the flexible ring (2a) which also mechanically holds the handle portion (3) and the head portion (2) together. The torque arm force applied to the lever end (3a) of the handle portion (3) is substantially increased by the mechanical advantage of the lever action and the resultant force acts on a pawl (3c) incorporated in the levered end (3b) of the handle portion (3). The pawl (3c) acts on a tooth or suitable projection (2c) incorporated in the free end of the flexible ring (2a) on to the outer surface (4a) of the circular drive (4) serving to lock the flexible ring (2a) and the circular drive (4) together. The torque applied to the handle portion (3) can then be usefully used to operate a known socket or drive bit through a square drive recess (4b) and complementary socket square drive (5) to operate a known fastener. To usefully prevent undue slippage the flexible ring (2a) has a resilient bias upon the circular drive (4). This is substantially decreased when the handle portion (3) is operated in the reverse drive direction (®. The degree of friction between the flexible ring inner surface (2b) and circular drive outer surface (4a) causing the flexible ring (2) to open just enough to allow the flexible ring (2) to rotate relative to the circular drive (4).