GB2376718A

GB2376718A - Letter flap assembly

Info

Publication number: GB2376718A
Application number: GB0115457A
Authority: GB
Inventors: Christopher James Homfray
Original assignee: Paddock Fabrications Ltd
Current assignee: Paddock Fabrications Ltd
Priority date: 2001-06-23
Filing date: 2001-06-23
Publication date: 2002-12-24
Anticipated expiration: 2021-06-23
Also published as: GB2376718B; GB0115457D0

Abstract

An assembly comprises a letter flap and body where the flap is pivotally connected to the body by means of a torsion bar (25), said bar being non-rotatably mounted to the flap at a first end, and having a laterally extending limb (29) at a second, opposing end, which in use engages in a recess (35) in the body. Preferably the limb includes a laterally projecting tag (31), which in use, is trapped in the recess between the body and a door to which the body is fitted. Furthermore the tag may be fitted with a barb (32) which snap fits into a groove (36a) to secure the bar. The flap may be mounted to the body by two axially aligned bars.

Description

LETTER PLATES This invention relates to a letter plate primarily, but not exclusively, for use on a domestic door.

It is known to provide a letter plate which includes a moulded synthetic resin body having a tubular element which extends within a corresponding aperture through the door or the like to which the letter plate is fitted, and integral with the tubular element, a flange arrangement which abuts the outer face of the door around said aperture. The known letter plate further includes a metallic flap which is hinged to the body and closes the outer end of the tubular element in use. The flange arrangement of the body and the metallic flap are designed to provide an aesthetically pleasing appearance to the letter plate at the outer face of the door or the like. It is recognised that a second, similar letter plate may fit to the rear face of the door, the tubular element of the second letter plate telescoping with the tubular element of the first letter plate and the two letter plates being interconnected by bolts, screws, or the like engaging, or passing through the structure of the door to define a letter plate assembly.

In the known letter plate the means hinging the flap to the body includes an elongate torsion bar one end of which is non-rotatably received in the flap and the opposite end of which has a non-circular region non-rotatably received as a push fit in a correspondingly non-circular passage in the body.

The torsion bar defines the pivot axis of the flap relative to the body and during assembly is torsionally stressed so that in the assembled letter plate the torsion bar urges the flap to pivot to a closed position in the body. It is

co2juu tjLt3 juA < nj Mn *jnjjtjm t* ouuL tjjjum tjLjtSjAcsL sxiSjuLy so Rs o L & "L A""O -WLVA"AA UL4-L L"A"^JL"". y OW CLO LW protrude from the body thereby releasing the stress urging the flap to its closed position, looking unsightly, and ultimately permitting the flap to become detached from the body and it is an object of the present invention to provide a letter plate wherein this disadvantage is minimised or obviated.

In accordance with one example of the present invention there is provided a letter plate comprising a body for attachment to a door or the like, the body including a flange arrangement which engages the face of the door or the like in use around the aperture of the door through which post is to be inserted in use, and a substantially planar flap of rectangular form, said flap being connected to said flange arrangement for pivotal movement relative thereto about an axis lying within, or substantially within, the body and parallel to and adjacent one longitudinal edge of the flap, by means including an elongate torsion bar having one axial end non-rotatably mounted to the flap and having at its opposite end a laterally extending limb received in a corresponding groove in the wall of the body.

Desirably said torsion bar is a snap-fit in said body.

Preferably said limb of said torsion bar includes a laterally projecting tag received in a groove in the rear face of said body so as to be trapped in use between the body and the door or the like to which the body is fitted.

Desirably said tag has an integral barb projecting laterally therefrom and received in use in a recess in said body to resist longitudinal movement of the torsion bar relative to the body.

Conveniently said recess is in the base of said groove in the rear face of the body.

Preferably said barb and said recess are so shaped that the barb can be engaged in the recess as a snap-fit as the torsion bar is engaged with the body.

Preferably the outer face of said laterally extending limb is shaped to be flush with the corresponding region of the outer profile of the body when the torsion bar is fully assembled to the body.

Conveniently the flap is mounted to the body by two axially aligned torsion bars.

One example of the invention is illustrated in the accompanying drawings wherein: Figure 1 is a plan view of a component of a letter plate; Figure 2 is a front elevational view of the component shown in Figure 1; Figure 3 is a side elevational view of the component; Figure 4 is a transverse cross-sectional view in a plane parallel to the plane of Figure 3;

Figure 5 is a scrap view illustrating the interconnection of two of the components of the letter plate; Figure 6 is an enlarged cross-sectional view illustrating two of the components of the letter plate in a closed position; Figure 7 is a view similar to Figure 6 illustrating the parts in an open position; Figure 8 is an enlarged sectional view illustrating the securing of a torsion bar component of the letter plate; and Figures 9 and 10 are respectively plan and side elevational views of the torsion bar seen in part in Figure 8.

The term"letter plate"is used herein to denote an assembly which fits at the outer, or inner, face of a door or the like in association with an aperture through the door or the like for the introduction of mail and other items.

Generally letter plates will be fixed at the front and rear of the door and a combination of two letter plates used in this way is often referred to as a letter plate assembly. Other terminology is often used in that a letter plate is sometimes referred to as a letter flap or a letter box.

Referring to the drawings the letter plate includes a moulded synthetic resin body 11 incorporating a tubular element 12 of rectangular cross-section, and integral with the tubular element at one end thereof, a generally rectangular flange arrangement 13 protruding outwardly at right angles to the length of

the tubular element 12. Although it is preferred to form the body 11 as a one piece synthetic resin moulding it is to be understood that the body could be a fabrication of individually formed elements and either as one piece or as a fabrication the body, or parts thereof could be formed from other materials, for example metal pressings or die castings.

In use the tubular element 12 extends through a correspondingly shaped aperture in the door to which the letter plate is affixed, and the rear face of the flange arrangement 13 abuts the outer face of the door around the aperture. If desired a gasket can be interposed between the flange 13 and the outer face of the door. Usually a second, similar letter plate is affixed at the inner face of the door and the tubular element of the inner letter plate is of slightly larger dimensions than the tubular element 12 so that the tubular element 12 can fit within the tubular element of the second letter plate in telescoping arrangement within the thickness of the door. It can be seen that the tubular element 12 has rows of transverse ridges 14 on its outer surface and these mesh with similar transverse ridges on the inner surface of the tubular element of the second letter plate to hold the two letter plates in position relative to one another defining the letter plate assembly, prior to introduction of securing screws which pass into or through the door.

The tubular element 12 opens, at its front end, into the base of a recess 15 defined in the front face of the flange arrangement 13. The flange arrangement 13 is rectangular in front view and the recess 15 is bounded on the two short sides of the flange assembly by forwardly protruding walls 16, 17 which are disposed vertically in the normal orientation of the letter plate.

A forwardly protruding wall 18 at the upper edge of the recess 15 extends

horizontally in use and is integral at its ends with the walls 16-17 respectively. There is no wall equivalent to the wall 18 bounding the lower edge of the recess 15.

Upstanding from the base of the recess 15 around the aperture of the tubular element 12 is an integral boss 19 having therein a groove within which is secured a continuous neoprene gasket 21.

The front face of the flange arrangement 13 is closed in use by a generally planar flap 22 conveniently formed as an aluminium extrusion. The flap 22 is rectangular, fitting with the confines of the recess 15 of the flange arrangement. As is best seen in Figure 6 and 7 the flap 22 has an enlarged bead along its upper edge, the bead containing a longitudinally extending passage 23 of circular cross-section accessible at opposite axial ends of the bead, and along the rear face of the bead by means of a slot 24 formed in the bead.

The flap 22 is retained in position relative to the flange arrangement 13 by means of a pair of identical moulded synthetic resin torsion bars 25 (see Figure 8 to 10). Each torsion bar comprises an elongate rod of circular cross-section having a longitudinally extending, integral, radially projecting rib 26 adjacent one axial end. At its opposite end the rod has the form of a shepherd's crook, comprising an integral head portion consisting of a first region 27 of circular cross-section coextensive with the remainder of the rod, but of slightly larger diameter than the rod. The region 27 terminates in an end portion 28 of square cross-section from which protrudes an integral, laterally extending limb 29 also of rectangular cross-section. The limb 29

extends generally at right angles to the length of the torsion bar and in the form in which the torsion bar is moulded the limb 29 protrudes from the torsion bar at a position spaced by 180 around the axis of the torsion bar from the rib 26. This is the configuration of the torsion bar which is illustrated in Figures 9 and 10.

At its outermost end the limb 29 carries an integral, laterally extending tag 31 of rectangular cross-section. The tag 31 extends parallel with the rod of the torsion bar, and is spaced therefrom by the length of the limb 29. At its free end the innermost face of the tag 31 is formed with an integral, inwardly protruding barb 32 which extends towards the axis of the torsion bar. The barb 32 defines a right angled shoulder 33 presented to the inner face of the limb 29 and opposite the face 33 the barb 32 has an inclined face 34.

When the letter plate is assembled one of the torsion bars 25 extends through the wall 16 of the flange arrangement 12 and into the passage 23 of the flap, while the other torsion bar extends similarly through the wall 17 of the flange arrangement and into the passage 23 of the flap 22. The arrangement at the wall 17 is similar to the arrangement at the wall 16 and is best seen in Figure 8.

As can be seen in Figure 8 the wall 16 has a through passage 34 to receive the portion 28 of the torsion bar. The through passage 34 is of square crosssection corresponding to the square cross-section of the portion 28.

Moreover, the outer edge of the wall 16 is recessed at 35 to receive the limb 29 of the torsion bar, the outer face of the limb 29 of the torsion bar being profiled to correspond to the profile of the outer surface of the wall 16.

Moreover, the recess 35 extends at 36- into the rear face of the flange I I---4 ; 1 assembly 13 presented to the door in use. The region 36 of the recess receives the tag 31 in use, and the recess 36 is extended at 36a into the material of the wall 16 so as to accommodate the barb 32.

When assembling the letter plate the flap 22 is introduced into the recess 15 of the flange arrangement 13 such that the bead of the flap lies adjacent the inner face of the wall 18 and the planar rear face of the flap seats on the neoprene seal 21. A first torsion bar 25 is then introduced through the passage 31 of the wall 16, the end of the torsion bar carrying the rib 26 being introduced first, and the torsion bar being rotated so that the rib 26 occupies a comer of the square cross-section passage 34 so that the rib and torsion bar can pass through the passage 34. The end of the torsion bar is then introduced into the passage 23 of the bead of the flap 22, the torsion bar having been rotated to engage the rod of the torsion bar in the passage 23 while the rib 26 lies within, and slides along the slot 24. In this orientation of the torsion bar the limb 29 is projecting outwardly beyond the plane of the front face of the letter plate since the rib 26 and the rib 29 are at 180 spacing from one another around the axis of the torsion bar.

However, before the torsion bar has been inserted sufficiently far for the portion 28 to enter the passage 34 the torsion bar is twisted relative to the flap 22 through 180 in a clockwise direction (as viewed in Figures 6 and 7).

The torsion bar is rotated by twisting the head end of the torsion bar relative to the remainder of the torsion bar which cannot rotate because the rib 26 is engaged in the slot 24 of the flap. The direction of twisting of the torsion bar is such as to tend to rotate the flap 22 about the axis of the torsion bar in a

direction to press the flap against the neoprene seal 21. After 180 of twist the limb 29 will be aligned with the recess 35 and the torsion bar can then be pressed fully home into the letter plate. The portion 28 of the torsion bar seats in the passage 34, the limb 29 seats in the recess 35, the tag 31 seats in the extension 36 of the recess and the barb 32 enters the region 36a of the recess as a snap-fit. It will be recognised that during the final insertion of the torsion bar the inclined surface 34 of the barb 32 rides on the base of the recess 35,36 thus flexing the torsion bar to allow the barb 32 to ride over the base of the recess 35,36 and to enter the enlargement 36a of the recess with a snap-fit. Thereafter, the surface 33 of the barb is abutting a corresponding surface of the recess 36a and thus resists withdrawal of the torsion bar from the letter plate. Moreover, as mentioned above the profile of the outer surface of the limb 29 matches the profile of the outer surface of the wall 16 so that the surface of the wall 16, after insertion of the torsion bar, appears to be continuous and the torsion bar is not immediately visible, its colour being the same colour as the wall 16. The second torsion bar is inserted through the wall 17 in exactly the same way, and the second torsion bar is twisted through 180 again in a direction to urge the flap to the closed position in which it seats on the seal 21.

It will be recognised therefore that the two torsion bars provide a pivotal mounting of the flap 22 in the body 11, and furthermore provide a means for resiliently urging the flap to its closed position in which the planar rear face of the flap 22 abuts the front face of the seal 21 around the aperture of the tubular element 12. In use the flap 22, in its closed position, lies wholly within the recess 15 and the absence of a lower wall in the recess 15 allows the user to grasp the free lower edge of the flap 22 to pivot the flap 22 to an

open position in use. Although the bead at the opposite edge of the flap lies Op-en posilliion-'L-U-Jrr---C,-- beneath the wall 18, and so is shielded by the wall 18 against ingress of rain and the like between the flap and the flange arrangement, nevertheless the shaping of the bead, and the positioning of the pivot axis of the flap is such that the flap 22 can be open through approximately 1500 as shown in Figure 7. When the letter plate is secured to the face of the door the tag 31 of each torsion bar is, in effect, trapped between the flange arrangement of the letter plate and the face of the door thereby preventing flexure of the torsion bar to permit displacement of the barb 32 from the recess 36a. In use therefore the torsion bar is positively locked in position relative to the flange arrangement 13 of the letter plate both axially, by the barb 32, and angularly by engagement of the limb 29 in the recess 35.

The letter plate attached to the inner face of the door can have a similar flap and torsion bar arrangement, but will probably utilise a brush seal of known form rather than the seal 21. The two letter plates may be individually screwed to the door by fixing screws passing through apertured bosses 38 in the flange arrangement beneath the flap 22, and/or they may be interconnected by screw fixing arrangements extending through bores in the door from the rear letter plate to engage in hollow internally screw threaded posts 39 protruding rearwardly from the flange arrangement of the outer letter plate.

While it is preferable to mount each flap 22 by means of a pair of oppositely directed torsion bars, it is to be recognised that if desired each flap could be mounted at one end by means of a torsion bar 25 as described above, and mounted at its opposite end by an alternative pivot arrangement.

Claims

CLAIMS :- 1. A letter plate comprising a body for attachment to a door or the like, the body including a flange arrangement which engages the face of the door or the like in use around the aperture of the door through which mail is to be inserted in use, and a substantially planar flap of rectangular form, said flap being connected to said flange arrangement for pivotal movement relative thereto about an axis lying within, or substantially within, the body and parallel to and adjacent one longitudinal edge of the flap, by means including an elongate torsion bar having one axial end non-rotatably mounted to the flap and having at its opposite end a laterally extending limb received in a corresponding groove in the wall of the body.
2. A letter plate as claimed in claim 1 wherein said torsion bar is a snapfit in said body.
3. A letter plate as claimed in claim 1 or claim 2 wherein said limb of said torsion bar includes a laterally projecting tag received in a groove in the rear face of said body so as to be trapped in use between the body and the door or the like to which the body is fitted.
4. A letter plate as claimed in any one of claims 1 to 3 wherein said tag has an integral barb projecting laterally therefrom and received in use in a recess in said body to resist longitudinal movement of the torsion bar relative to the body.

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5. A letter plate as claimed in claim 4 where dependent upon claim 3 wherein said recess is in the base of said groove in the rear face of the body.
6. A letter plate as claimed in claim 4 or claim 5 wherein said barb and said recess are so shaped that the barb can be engaged in the recess as a snapfit as the torsion bar is engaged with the body.
7. A letter plate as claimed in any one of claims 1 to 6 wherein the outer face of said laterally extending limb is shaped to be flush with the corresponding region of the outer profile of the body when the torsion bar is fully assembled to the body.
8. A letter plate as claimed in any one of claims 1 to 7 wherein the flap is mounted to the body by two axially aligned torsion bars.