A safety hinge

Abstract: A safety hinge for windows and doors comprises hinge parts (1, 2) for fastening on a frame (4) and an opening leaf or sash part (5), respectively, and has tubular guideways (6-8) which form a continuous tubular bearing for removable, axial retention of a hinge pin (9). The bearing is closed at one end and open at the other end and is of a greater length than the pin (9) so that the said pin does not project from the open end. For removal of the pin (9), an opening (11, 12) is formed on a side of at least one guideway (6, 7), which is inaccessible in the closed position of the sash part (5), for insertion of a tool for impact on the pin (9) for disengagement from the axial retention.

Description: The present invention relates to a safety hinge, as set forth in the preamble of claim 1. In a design of a safety hinge disclosed in FR-A1-2 616 173, the hinge pin is axially locked with respect to the guideway formed by the second hinge part of a three-knuckle hinge by means of a locking screw screwed into the pin through a hole formed in said guideway. For removal of the pin, the locking screw must be disengaged from the pin, which may therefore be retracted from the bearing through the open end thereof after removal of a closing screw inserted in said open end. If by oversight or some other reason the locking screw is not mounted, the intended safety against unauthorized dismounting of the hinge is not established, since the hinge pin can be fairly easily removed in any position of the leaf or sash part by removal of the closing screw from the open end of the bearing, whereby the window or door can be dismounted. The same disadvantage applies to a two-knuckle hinge design disclosed in US-A-4,475,266. The object of the present invention is to provide a hinge of a simple design in which the hinge pin is effectively secured against removal in the closed position of the leaf or sash part without the use of securing screws or similar additional securing elements, so that safety against burglary is always provided in this position. This is achieved according to the invention by a design of a safety hinge of the type as stated in the characterizing part of claim 1. By this design the pin can only be removed in the open position of the leaf or sash part by insertion of a tool for engagement with the pin through the said side opening. In the closed position, the closed end of the bearing prevents removal of the pin by axial impact, for example by means of a punch, and as the pin does not project from the open end of the bearing there is no possibility of removal by means of nippers or the like. Due to the absence of a securing screw or similar additional securing elements there is no risk of oversights in connection with the mounting leading to lack of securing of the hinge. Suitable embodiments of the safety hinge according to the invention are stated in the dependent claims. The hinge parts and the pin can be made of materials of the necessary strength and corrosion resistance, such as iron alloys, bronze alloys or light metal alloys, if necessary with a corrosion-resistant coating. Synthetic materials of the required strength can also be used. The hinge can be manufactured by conventional processes comprising, for example, punching or bending of plate-shaped material or casting or forging. Preferred embodiments of the invention will now be explained in further detail below with reference to the schematic drawing, in which Fig. 1 is a perspective view of a three-knuckle design of the safety hinge according to the invention shown in the open position of the leaf or sash part of an opening window, Fig. 2 is a cross-sectional view of the embodiment in Fig. 1 along the line II-II, Fig. 3 is an axially sectional view of the embodiment in Fig. 1 along the line II-II, Fig. 4 is a perspective view of a two-knuckle design of the hinge, and Fig. 5 is an axially sectional view of a modification of the embodiment shown in Fig. 4. In the embodiment shown in Figs. 1-3 the safety hinge according to the invention has three knuckles and comprises a first hinge part 1 for fastening on a frame 4, such as a window frame, a second hinge part 2 for fastening on the opening sash part 5 of the window and a hinge pin 9. The hinge parts 1 and 2 each has a fastening part 3 and 3a, respectively, in the form of a conventional plate element with holes for screws or other retaining elements for secure fastening of the hinge parts 1 and 2 to the frame 4 and the sash part 5, respectively. In the embodiment shown, the fastening part 3 for the hinge part 1 is formed as a plate angle, a so-called angle brace, which makes it more difficult to remove the hinge part 1 once it has been mounted on the frame 4. In connection with the fastening part 3, the hinge part 1 is formed with first and second tubular hinge knuckles 6 and 7 forming together a common first guideway and leaving an interspace for positioning of a third tubular hinge knuckle providing a second guideway 8 pertaining to the second hinge part 2. The guideways 6-7 and 8 form together a tubular bearing for reception of a hinge pin 9 and provision of the assembled hinge. In the illustrated embodiment axial retention of the pin 9 in the bearing is secured solely by press fitting of the pin into the guideway 6, as the inner surface of the guideway 6 and the part of the pin 9 intended for insertion therein may, for example, be slightly conical as shown in Fig. 3. On the side accessible from the outside in the closed position of the sash part 5, the bearing formed by the guideways 6-7 and 8 has a continuous external surface. The first guideway 6-7 connected with the hinge part 1 is closed at one end so that the pin 9 is inaccessible through the said end. This renders it impossible to remove the pin 9 by axial impact, for example with a punch, from this closed end. At the end of the knuckle 7 on the hinge part 1 the first guideway is open for providing an open end of the assembled bearing for removal of the pin 9. However, the length of the pin 9 is shorter than the total length of the bearing formed by the guideways 6-7 and 8, and as shown in Fig. 3 the pin 9 is inserted in the bearing in the axial direction to have its end positioned at a distance from the closed end of the bearing so that the other end of the pin does not project from the open end of the bearing, which renders it impossible to remove the pin from the said end, for example by means of nippers or similar tools, in the closed position of the window. In the closed position of the window, in which the hinge parts 1 and 2 are folded together as shown in dashed lines in Fig. 2, the pin 9 thus presents no points of attack accessible from the outside and it thereby secured against unauthorized removal from the bearing. To permit dismounting of the hinge, e.g. for removal of the sash part 5 in its open position, for example in connection with painting or other repair or service of the window, an opening 11 is positioned on the side 10 of the first guideway 6 on the first hinge part 1, which is inaccessible in the closed position of the sash part 5, but which is accessible from the outside in the open position, the said opening being positioned in the axial direction on a level with the end surface 15 of the pin 9 inserted in the guideway 6. By insertion of a tool such as a screwdriver through the side opening 11, the pin 9 can be pushed in the axial direction towards the open end of the bearing at the end of the second knuckle 7 and thus be disengaged from its axial retention in the bearing by press fitting into the guideway 6. To further facilitate the removal of the pin 9 from the bearing, the embodiment shown in Figs 1-3 comprises a further opening 12 in the form of a recess at the open end of the bearing formed by the knuckle 7, said recess being accessible only in the open position of the sash part 5. In the vicinity of its end surface inserted in the guideway 7, the pin 9 is formed with a transverse hose 13 which by release of the pin is brought into alignment with the recess 12. By insertion of a suitable tool through the recess 12 into the hole 13, the pin can be removed from the bearing. In the embodiment shown, the recess 12 also functions as an engaging part for radial and axial positioning of the pin 9, as the pin 9 is provided with a lug 14 projecting from its end surface. At insertion of the pin 9 into the bearing, the lug 14 is pushed into the recess 12, thereby achieving exact positioning of the pin 9 both axially, so that the end surface 15 is placed on a level with the opening 11 in the first guideway 6, and radially for angular positioning the hole 13 with respect to the recess 12 in the second guideway 7. The design of the second knuckle 7 with the recess 12 and the pin with the hole 13 in correspondence therewith and the engaging lug 14 is not, however, a necessary characteristic of the hinge according to the invention, as the desired possibility of removing the pin 9 in the open position of the sash part 5 can be provided solely by means of the opening 11 in the first knuckle 6 positioned on a level with the end surface 15 of the pin 9. Advantageously, the opening 11 as shown in Fig. 1 is formed as an axially extending slot, which provides a certain amount of tolerance in respect of the positioning of the end surface 15 when the pin 9 is pressed into the guideway 6. For the purpose of removing the pin 9 by insertion of a tool through the opening 11, the pin 9 may alternatively be manufactured with a hole or a recess, with which the inserted tool engages instead of acting direct on the end surface 15 of the pin. Alternatively, disengagement of the pin 9 for removal from the bearing can be effected by insertion of a tool below the lug 14 pressed into the recess 12, whereby the opening 11 in the knuckle 6 with the closed end can be dispensed with. The embodiment shown in Figs. 4 and 5 comprises a knuckle hinge with guideways 17 and 18 formed by the knuckles of two respective hinge parts 19 and 20 intended to be fastened on a sash part and a frame part, respectively, of the window. For securing the axial retention of the pin 21 in the bearing formed by the two guideways 17 and 18, the pin 21 may, in this embodiment, either be inserted with relatively tight press fitting into the guideway 18 containing the closed end of the bearing, whereby the guideway 17 must be freely pivotable with the pin 21 acting as fulcrum, or alternatively a recess 22 may as illustrated be formed at the open end of the guideway 17 for engagement with a projecting lug 13 from the corresponding end of the hinge part 21, whereby the hinge part 21 must be freely turnable inside the second guideway 18. In case of fastening of the pin 21 by press fitting with respect to guideway 18 removal of the pin 21 is provided for by forming 18 with an opening 22 corresponding to the opening 11 in Figs 1 to 3. In the alternative embodiment with engagement between a lug 25 and a recess 23 the pin 21 may be formed with a transverse hole 24 in the same way as described above for the embodiment in Figs. 1-3. The two-knuckle hinge in Figs. 4 and 5 is substantially suited for horizontal mounting, for example as a hinge for a top-hung window, while the hinge designed with three or more knuckles can be used both for horizontal and vertical mounting, in the latter case with optional orientation of the bearing with the open end facing upwards as shown in Fig. 1 or downwards.

Claims: A safety hinge, preferably for windows and doors, comprising a first hinge part (1, 19) for fastening on a stationary frame part (4) and a second hinge part (2, 20) for fastening on an opening leaf or sash part (5), said hinge parts forming respective substantially tubular first and second guideways (6-7,8; 17, 18) in mutual axial alignment to form together a substantially continuous tubular bearing for removable axially positioned retention of a hinge pin (9, 21), said bearing being closed at one end and open at the other end, said hinge pin (9, 21) having a shorter length than said bearing so as to be insertable into said bearing towards the closed end thereof without projecting from the open end of the bearing, characterized in that the hinge pin (9, 21) is engaged by one of said (6-7, 17) guideways so as to be radially and axially fixed with respect to said one guideway, and that an opening (11, 12; 22, 23) is provided in said one guideway (6, 7; 17, 18) in a position thereon to be accessible only in the open position of the leaf or sash part (5) for insertion of a tool to act on the hinge pin (9, 21) for disengagement of the hinge pin from its engagement with said one guideway. A safety hinge according to claim 1, characterized in that said one guideway (6-7, 18) provides the closed end of the bearing. A safety hinge according to claim 2, characterized in that the hinge pin (9, 21) is so much shorter than the total length of the bearing that the inserted end (15) of the pin is positioned at a distance from the closed end of the bearing, said opening (11, 22) being formed adjacent the closed end of the bearing to permit engagement of the end of the hinge pin (9, 21) by insertion of said tool through the opening. A safety hinge according to claim 2, characterized in that said one guideway is provided by said first guideway (6-7) and contains also the open end of the bearing in a three-knuckle design of the bearing. A safety hinge according to claim 1, characterized in that said opening is formed as a recess (12, 23) at the open end of said bearing (7), and that the hinge pin (9, 21) is formed with a projecting lug (14, 25) for engagement in said recess (12, 23) for radially and axially fixed positioning of the pin (9, 21) with respect to the bearing. A safety hinge according to claim 5, characterized in that below said lug (14, 15) the hinge pin (9, 21) is formed with a transverse hole (13, 24), which by disengagement of the pin (9, 21) from the recess is brought into alignment with the recess (12, 23). A safety hinge according to any of claims 3,5 and 6, characterized in that said first and second guideways (17, 18) provide the open and closed ends of the bearing, respectively, in a two-knuckle design of the hinge. A safety hinge according to any of the claims 2-6, characterized in that the pin (9, 21) is engaged by press fitting at least in the part (6) of said one guideway (6-7, 18) adjacent the closed end of the bearing. A safety hinge according to claim 8, characterized in that said part of said one guideway (6-7, 18) and a part of the pin (9, 21) engaged therewith are slightly conical.

Inventors: JEPSEN LARS HOUMANN, SMEDEGAARD KAJ, JEPSEN, LARS HOUMANN, SMEDEGAARD, KAJ
Applicants: VKR HOLDING AS, VKR HOLDING A/S
Application year: 1998
Main classification: E05D5
IPC codes: E05D5, E05D11, E05D7