AU4578702A - Flush handle latch assembly - Google Patents

Description

P/00/011 28/5/91 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: FLUSH HANDLE LATCH ASSEMBLY The following statement is a full description of this invention, including the best method of performing it known to us FLUSH HANDLE LATCH ASSEMBLY The present invention relates to improvements in flush handle latch assemblies which may or may not include a locking facility.

Flush handle latch assemblies of the aforementioned kind are well know.

They typically include an outwardly located fascia plate having a recess in which a rotatable grip member is located. The grip member is connected to an inwardly located cam plate which includes a latch tongue that can be positioned in a latching or delatching position by rotation of the outer grip member. In the case of such an assembly that is lockable, a lock barrel may be operably mounted through the fascia plate that is key actuated from the front and which co-operates with the cam plate at its rear to either lock the cam plate against rotation or free same depending on whether the lock barrel is locked or unlocked. Typically the fascia plate may be made from die cast metal which is painted to finish same.

The cam plate may also include a pair of rearwardly directed pins mounted thereto on opposed sides of its rotational axis which may provide for mounting of three point locking links if required. The assembly thus described is retained together by a retainer plate and a screw member, the retainer plate being hat shaped with outer flange portions having small apertures that are engagable with the end zones of the pair of pins of the cam plate, and the screw member being passed through a central opening in the retainer plate to be threadably connected to the outer grip member. The fascia member is typically snap fitted onto a suitably shaped opening in the door, drawer or the like that is to be latched by the flush handle latch assembly. Such flush handle latch assemblies have operated satisfactorily for a number of years, however, they do have some practical disadvantages. Firstly, their construction is a little complex and certain parts in the construction tend to increase the costs of the product. Secondly, in a relatively few cases, the screw holding the assembly together has a tendency to loosen which, if it occurs to a certain stage, can adversely affect operation of the latch assembly.

The objective of the present invention is to provide a flush handle latch assembly of the aforementioned kind which avoids the need to utilise a screw member to hold the assembly together. A preferred objective is to provide a flush handle latch assembly which can be produced at a lower cost than existing such assemblies.

Accordingly, the present invention provides a latch assembly including a fascia plate, a grip member located at least partially outwardly of said fascia plate and being mounted for rotation relative to said fascia plate, a cam plate including a laterally projecting latch tongue located inwardly of said fascia plate, a rotation drive connection between said grip member and said cam plate whereby in an assembled condition, said grip member and said cam plate rotate together, and a retainer member interengagable with said grip member in a plurality of positions, said retainer member being movable axially to engage with or disengage from said grip member in a first relative rotational position, said retainer member being relatively rotatable from said first relative rotational position to a second relative rotational position providing a said assembled condition of said latch assembly where disengagement of the retainer member from said grip member in an axial direction is prevented. Preferably relative rotational movement towards or away from said first position is inhibited when the assembly is in said second relative rotational position. By the terminology "inhibited", it is meant to convey that relative rotation towards or away from said first position is possible only by applying a predetermined significant rotational force between the retainer member and the grip member.

In a particularly preferred embodiment, the retainer member is capable of being moved rotationally to a third relative rotational position, beyond said second position in a direction away from said first position, where the retainer member, said cam plate and said grip member are substantially retained together against relative axial or rotational movement. Conveniently the first mentioned assembled condition is useful for transporting the latch assembly to an end user of the assembly and the second mentioned retained condition is utilised when the end user of the latch assembly installs same into a door, drawer face or the like.

Further preferred features of this invention may be as defined in claims 4 to 10 inclusive annexed hereto which are hereby made part of the disclosure of this specification.

A preferred embodiment of the present invention will hereinafter be described with reference to the accompanying drawings, in which Fig 1 is an exploded view of the parts forming a non lockable flush mounting latch assembly according to the present invention; Fig 2 is a view similar to Fig 1 but showing a lockable version of the latch assembly; Fig 3 is a detailed perspective view of the grip housing part forming part of the grip member of the embodiments shown in Figs 1 and 2; Fig 4 is a detailed perspective view of cam plate as shown in Figs 1 and 2; Fig 5 is a detailed perspective view of the retainer member shown in Figs 1 and 2; and Figs 6a, 6b and 6c are rear elevation views of the latch assembly showing the retainer member in three different positions.

A flush mounting latch assembly (10) according to a preferred embodiment of this invention includes a fascia plate 1 having clip formations 7 formed in a rearwardly facing surface to allow the fascia plate 1 to be snap fitted into an opening in a door face, drawer face or the like. The fascia plate 1 includes a recessed zone 8 adapted to rotationally receive a grip member 9 which may conveniently be made up from two parts, a grip part 2 and a grip housing part Conveniently the grip housing part 5 and the grip part 2 include inter engagable formations 13 enabling snap fitting of the grip housing part 5 into and with the grip part 2 to form the grip member 9. The assembly further includes a wave washer 11, a cam plate 4 including a latching tongue 12 and a retainer member 6. The assembly 10' of Fig 2 differs from that of Fig 1 in that a lock barrel 3 is included which enables the latch to be locked in a locking position but which is not further described hereinafter as this does not relate to the invention of this specification.

As can be best seen in Figures 3 to 5, the grip housing part 5 includes a ring section 14 adapted to receive and co-operate with a lock barrel 3 if such is required, and a body section 15 from which a formation 16 extends. The formation 16 includes a first cylindrical section 17 having a circular circumferential surface 18 which in use is located within a circular aperture 19 extending centrally through the fascia plate 1 within the recessed zone 8. The cylindrical section 17 and the aperture 19 provide a bearing for rotation of a sub assembly formed by the grip member 10, the cam plate 4 and the retainer member 6. Axially beyond the cylindrical section 17 is a rotational drive formation 20 formed with a square or non-circular shaped circumferential surface 21 which, in use, engages in a complementary shaped aperture 22 in the cam plate 4. Still further, beyond the rotational drive formation 20 is a cylindrical section 23 with diametrically opposed tab formations 24, 25 extending transversely from a cylindrical edge zone of the cylindrical section 23. Conveniently the grip housing part 5 may be die cast from a suitable metal whereas the grip part 2 may be moulded from a suitable hard wearing plastics material.

The cam plate 4, as shown in Fig 4 may include a pair of diametrically opposed projections 26, 27 formed from the plate material forming the cam plate itself. In this manner separate processing steps of connection pin members to the cam plate 4 is avoided. A preferred retainer member 6 is shown in Figures 5 and 1/2. The retainer member 6 has a centrally located boss formation 28 with bore 29 passing therethrough. Within the internal bore 29, a pair of opposed recessed openings 30, 31 are provided dimensioned to allow the tab formations 24, 25 to pass therethrough. From each of the recessed openings 30, 31, a retainer ledge 32 extends in a clockwise direction ending at a stop abutment 33, with only one of these ledges 32 being seen in Fig 5. Each ledge 32 extending from the recessed opening 30 or 31, includes a ramp surface 34 angled towards its rear most surface 35 and immediately a second ramp surface 36 leading to a section 37 equally or marginally greater in length than the width of the tab formations 24, A third ramp surface 38 leads from the section 37 to a second section 39 which in turn extends to the abutment 33.

Assembly of the latch assembly shown in the drawings and described above is generally as follows. Firstly, the grip part 2 and the grip housing part are assembled to form a grip member 9. Thereafter the grip member 9 is located within the recessed zone 8 of the fascia plate 1 with the formation 16 extending through the fascia plate aperture 19. The wave washer 11 is placed over the formation 16 followed by the cam plate 4 ensuring that the rotational drive surfaces 21 are in engagement with the complementary shaped surfaces 22 of the aperture in the cam plate 4. The retainer member 6 is then placed over the projection 16 with the tab formations 24, 25 aligned with the recessed openings 31 of the bore 29 and with the free surface 40 of the boss formation 28 pressed against the adjacent surface of the cam plate 4. In this position (Fig 6a), the retainer member 6 can be rotated in the direction of arrows 41 with the tab formations 24, 25 riding over the ramp surfaces 34, 36 to position the tab formations 24, 25 in the regions 37 of the ledge 32 (as shown in Fig 6b). In this "assembled" position, the latch assembly can be shipped to an end user who may then install same in a door, drawer or the like. In this condition, the locking bars (not shown), if required, may be fitted to the projecting lugs 26, 27 and the retainer member 6 may be further rotated in the direction of arrows 41 whereby the tab formations 24, 25 ride over the ramp sections 38 to be positioned adjacent the stop abutments 33 on the ledge sections 39. At the same time ramps 44 on the surface 43 of the retainer member 6 enable the retainer member 6 to ride over the ends of the projecting lugs 26, 27 such that the ends finally rest and are retained in apertures 45 in the surface 43 of the retainer member 6. In this condition, the grip member 9, the cam plate 4 and the retainer member 6 are effectively locked together for rotation as a unit. Moreover, the locking bars (not shown) are retained between the retainer member 6 and the cam plate 4 with their ends connected via an aperture to the projecting lugs 26, 27. In this configuration it is impossible for the retainer member 6 to become loosened from this locked position with normal usage of the latch assembly.

Claims (5)

1. 4- 6 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A latch assembly including a fascia plate, a grip member located at least partially outwardly of said fascia plate and being mounted for rotation relative to said fascia plate, a cam plate including a laterally projecting latch tongue located inwardly of said fascia plate, a rotation drive connection between said grip member and said cam plate whereby in an assembled condition, said grip member and said cam plate rotate together, and a retainer member interengagable with said grip member in a plurality of positions, said retainer member being movable axially to engage with or disengage from said grip member in a first relative rotational position, said retainer member being relatively rotatable from said first relative rotational position to a second relative rotational position where disengagement of the retainer member from said grip member in an axial direction is prevented. 2. A latch assembly according to claim 1, wherein relative rotational movement towards or away from said first relative rotational position is inhibited when the assembly is in said second relative rotational position. 3. A latch assembly according to claim 1 or claim 2, wherein the retainer member is adapted for rotation to a third relative rotational position, beyond said second position in a direction away from said first position, where the retainer member, said cam plate and said grip member are retained together against relative axial or rotational movement. 4. A latch assembly according to any one of claims 1 to 3, wherein the grip member includes a first part adapted to be gripped by a user and located substantially outwardly of said fascia plate and a second part adapted to pass through an aperture in said fascia plate to be engaged by said retainer member rearwardly of said fascia plate. A latch assembly according to claim 4, wherein said first part of the grip member is located within a recessed region of said fascia plate. I., S I. 7
2. 6. A latch assembly according to claim 4 or claim 5, wherein said grip member is integrally formed.
3. 7. A latch assembly according to claim 4 or claim 5, wherein said first part and said second part of the grip member are separately formed, said first part and said second part including snap connector means to enable same to be connected together to form said grip member.
4. 8. A latch assembly according to claim 3 and any claim dependent from claim 3, wherein the cam plate includes a pair of axially rearwardly extending projections on diametrically opposed sides of an axis of rotation of a sub assembly of said retainer member, said cam plate and said grip member, free ends of said projections engaging and being retained in recesses in said retainer member upon relative rotation to said third relative rotational position.
5. 9. A latch assembly according to claim 8, wherein guide ramps are provided in said retainer member adjacent the retainer recesses. A latch assembly according to claim 8 or claim 9, wherein the projections are formed from said cam plate by deformation of the plate material forming said cam plate. DATED this 4th day of June, 2002 LOCK FOCUS PTY. LTD. WATERMARK PATENT TRADEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA P19753AU00 SKP:JC