LIFT-OFF HINGE ASSEMBLY

Abstract: A hinge assembly (10) including a first hinge leaf (11) hingedly connected to a second hinge leaf (12) by a hinge pin (14), the hinge pin (14) being detachably secured in one of the hinge leafs to enable separation of the hinge leafs, the hinge pin (14) being axially slidably received in a bore (12b) formed in said one hinge leaf, a retaining member (30) being screw threadedly received in a threaded bore extending generally tangentially to and intersecting said bore (12b) so as to define a window in the periphery of said threaded bore (12b), said retaining member (30) when screwed along said threaded bore (12b) engaging the periphery of the pin (14) projecting through said window to secure the pin relative to said one hinge leaf.

Description: The present invention relates to a lift-off hinge assembly which is particularly suitable for the mounting of vehicle doors. EP 0228187 discloses a hinge assembly including a first hinge leaf hingedly connected to a second hinge leaf by a hinge pin, the hinge pin being detachably secured in one of the hinge leafs to enable separation of the hinge leafs, the hinge pin being axially slidably received in a bore formed in said one hinge leaf, a retaining member being screw threadedly received in a threaded bore extending generally tangentially to and intersecting said bore, said retaining member when screwed along said threaded bore engaging the periphery of the pin to secure the pin relative to said one hinge leaf. In accordance with EP 0228187, a document falling under Article 54(3) EPC, the head portion of the retaining member engages the hinge pin. The head portion is conical in shape and is moved out of contact with the hinge pin by a relatively small axial displacement of the retaining member. According to the present invention as defined in indepentdent Claim 1 there is provided a hinge assembly including a first hinge leaf hingedly connected to a second hinge leaf by a hinge pin, the hinge pin being detachably secured in one of the hinge leafs to enable separation of the hinge leafs, the hinge pin being axially slidably received in a bore formed in said one hinge leaf, a retaining member being screw threadedly received in a threaded bore extending generally tangentially to and intersecting said bore, said retaining member when screwed along said threaded bore engaging the periphery of the pin to secure the pin relative to said one hinge leaf whereby a window is formed in the threaded portion of said threaded bore at the intersection between said bore and said threaded bore and that the hinge pin projects through said window into the threaded bore, the hinge pin and/or retaining member being deformed by passage of the retaining member axially along the threaded bore and passed said window. Preferred embodiments of the invention are defined in dependent Claims 2 to 4. Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which: Figure 1 is a side view of a hinge assembly according to the present invention; Figure 2 is a plan view from beneath of the hinge assembly shown in Figure 1; and Figure 3 is a sectional view taken along lines X-X in Figure 2. The hinge assembly is generally shown at 10 and includes a first hinge leaf 11 which is hingedly connected to a second hinge leaf 12 by a hinge pin 14. In use, hinge leaf 11 is attached to a vehicle door and hinge leaf 12 is attached to the vehicle body. The hinge pin 14 is rotatably received in a boss portion 11 a of the hinge leaf 11 and is restrained against axial withdrawal therefrom. In this respect, the pin 14 is provided with a peripheral flange 15 which acts to restrain relative axial movement in one direction between the pin 14 and boss portion 11 a . Relative axial movement between the pin 14 and boss 11 a in the opposite direction is prevented by a peripheral flange 16 formed at one terminal end of the pin 14. The peripehral flange 16 is formed by deformation of said one terminal end of the pin 14 after it has been introduced through the boss portion 11 a . A bush liner 18 is preferably located between the pin 14 and boss 11 a so as to provide a lubricated close tolerance fit therebetween. In this way pin 14 is able to rotate smoothly relative to boss 11 a without play. The liner 18 is preferably a plastics material reinforced with a metal mesh; Metaloplast (Registered Trade Mark) is a suitable material. The lower portion 14 a of the hinge pin 14 is received in a boss 12 a of leaf 12. The pin 14 has a lower terminal portion 14 b which is of chamfered configuration to facilitate entry of the pin portion 14 a into the bore 12 b formed in boss 12 a . In use, when the hinge leaf 12 is attached to the vehicle body the boss 12 a is located beneath boss 11 a so that the weight carried by hinge leaf 11 urges pin 14 axially toward boss 12 ensuring that the flange 15 rests on the upper surface of the boss 12 a . The pin 14 is detachably held within the boss 12 a by means of a screw threaded retaining member 30. The retaining member 30 acts to prevent axial withdrawal of the pin 14 from the boss 12 a and also acts to prevent relative rotation between the boss 12 a and pin 14. The retaining member 30 is received in a screw threaded bore 31 which extends generally tangentially relative to the bore 12 b such that bores 12 b and 31 intersect to provide a window or aperture located on the circumferential periphery of bore 31. Thus when the pin 14 is located within bore 12 b it penetrates radially a predetermined amount into bore 31. Accordingly when the retaining member 30 is screwed along bore 31 it will reach the window and interfere with the pin 14. The relative hardnesses of the materials used for the pin 14 and retaining member 30 are chosen such that deformation of the pin 14 and/or the retaining member 30 are/is caused as the retaining member 30 passes the window. In order to facilitate passage of the retaining member 30 passed the window the cross-sectional shape of the retaining member 30 is provided with flats. In this way the torque required for rotating the retaining member 30 is reduced whilst maintaining a desired amount of interference between the pin 14 and retaining member 30. In the illustrated embodiment the retaining member 30 is shown as being tri-lobal; it will be appreciated however that four or more flats may be provided. It is to be noted that herein a "flat" also covers curved surfaces having a relatively large radius of curvature. Initially the hinge 10 is preferably assembled such that the retaining member 30 is screwed along the bore 31 by a sufficient amount to only just grip the pin 14. In this way the retaining member 30 may be easily retracted along bore 31 to enable release of pin 14 and thereby enable the hinge 10 to be separated after mounting on the vehicle door and body. Preferably the hinge 10 is provided with a temporary stop for limiting the maximum open position of the vehicle door. In this respect a thin plate 48 is interposed between flange 16 and boss 11 a . The plate 48 is gripped. by the flange 16 and thereby is rotationally locked with respect to the pin 14. The plate 48 is provided with a stop portion 48 a which is arranged to abut against a projection 11 c on the hinge leaf boss 11 a and thereby provide a limit stop for limiting the amount of relative angular displacement between hinge leafs 11, 12. The hinge leaf 11 is provided with an interleafing projection 11 d which is engageable with boss 12 a to prevent axial separation of the hinge leafs 11, 12. The boss 12 a is shaped so as to not engage with projection 11 d when the leafs 11, 12 are opened to the position defined by stop 48 a . Accordingly separation of a door from a vehicle body is easily achieved by opening the door to the position defined by the stop 48 and then unscrewing retaining member 30 for each hinge 10 and then raising the door to axially separate the hinges. Use of the temporary stop is advantageous since it enables the vehicle to be painted without incorporating a separate conventional door check mechanism. After painting the doors are separated from the vehicle body for fitment. On remounting of the doors to the vehicle body, the temporary stop is no longer required and so the operative renders the temporary stop inoperable by bending the plate 48 to move the stop 48 a out of the path of travel of projection 11 c . The plate 48 may also be used at this time to rotate pin 14 within bore 12 b so as to present a fresh undeformed surface portion of the pin in the window of bore 31. The retaining member 30 is now screwed fully home along bore 31 which results in its head 30 a engaging the boss 12 a . In this position, the terminal end of the retaining member 30 has passed beyond the pin 14 thereby providing a secure connection between the pin 14 and retaining member 30. In this respect it will be appreciated that the connection between the retaining member 30 and pin 14 is maintained until the terminal end of the retaining member is retracted passed the pin 14. Thus the retaining member has to move axially a substantial distance before the connection with the pin 14 is broken. It is envisaged that the head 30 a may be arranged to interfere with hinge leaf 11 to prevent full closing of the door when the retaining member 30 has retracted by a predetermined distance prior to disconnection between the pin 14 and retaining member 30. In this way a warning is provided that the retaining member 30 is retracting from the pin 14 before the connection is actually broken.

Claims: 1. A hinge assembly including a first hinge leaf hingedly connected to a second hinge leaf by a hinge pin (14), the hinge pin being detachably secured in one of the hinge leafs (12) to enable separation of the hinge leafs, the hinge pin being axially slidably received in a bore (12b) formed in said one hinge leaf, a retaining member (30) being screw threadedly received in a threaded bore (31) extending generally tangentially to and intersecting said bore, said retaining member when screwed along said threaded bore engaging the periphery of the pin to secure the pin relative to said one hinge leaf whereby a window is formed in the threaded portion of said threaded bore (31) at the intersection between said bore (12b) and said threaded bore (31) and that the hinge pin (14) projects through said window into the threaded bore (31), the hinge pin and/or retaining member being deformed by passage of the retaining member axially along the threaded bore and passed said window. 2. A hinge assembly according to Claim 1 wherein the retaining member is provided with flats to facilitate passage of the retaining member passed the window. 3. A hinge assembly according to Claim 1 or 2 wherein the retaining member has a head (30a) which engages said one hinge leaf when the retaining member is fully inserted into said threaded bore, the head interfering with said other hinge leaf (11) when the retaining member has retracted from said threaded bore by a predetermined distance prior to disconnection between the hinge pin and the retaining member. 4. A hinge assembly according to Claim 1, 2 or 3 wherein a temporary stop plate (48) is provided secured to the hinge pin (14).

Inventors: AITKEN, CLIFF
Applicants: I.H.W. ENGINEERING LIMITED
Application year: 1988
Main classification: E05D7
IPC codes: E05D7