WEATHER STRIP IN PARTICULAR FOR WINDOW AND DOOR FRAMES AND THE LIKE

Abstract: A weather strip in particular for door and window frames is described, which comprises a base portion (2) to be fitted to a first bearing frame (4) and a head portion (5) acting in abutment on a second bearing frame (7). The base portion (2) comprises a holding element (8) of a stiff material and a push element (11) associated with the holding element (8) and having at least one first end portion (11a) adapted to act in abutment on the first frame (4) and to transmit a corresponding elastic thrust action to the holding element (8) to cause snap-fitting of the latter with the first frame (4).

Description: WEATHER STRIP IN PARTICULAR FOR WINDOW AND DOOR FRAMES AND THE LI KE D e s c r i p t i o n The present invention relates to a weather strip, in particular -for window and door -frames and the like. It is known that both in the field o-f external window and door -frames -for buildings and in the motor—vehicle -field, as well as in many other -fields, weather strips have been widely used which ar such arranged as to ensure an appropriate seal against atmospheric agents such as air, water or others. In particular, the weather strips referred to in the present description have an extension and shape capable; o-f matching the opening perimeter with which they are associated and, under operating conditions, they are interposed between a fixed portion such as a door or window casing or a car body for example, and a movable portion, such as the movable framework or sash of a door/window or the door of a motor-vehicle, for example. In a traditional manner, weather strips presently available on the market comprise a shaped base portion adapted to engage a corresponding anchoring area of one of the two bearing frames forming the door or window frames or fixtures. Usually connected with the base portion, upon interposition of an intermediate portion, is a head portion intended for acting in abutment against a rabbet area defined on the second frame o-f the fixture so that, by carrying out the fixture closure, the desired seal over the whole perimeter thereof is achieved. It is apparent that the sealing quality of the weather strip w ll be due to an appropriate planning of both the head portion and base portion. In particular, with reference to the base portion, it is to point out that it must ensure a steady and durable engagement between the weather strip and the fixture frame on the one hand, and a perfect tightness to any external agent on the other hand. For the purpose, many weather strip typologies have been developed in which the base portion is substantially defined by a bulged area joined to the remaining part of the weather strip by a narrow connecting portion or "neck". This type of base portion can be installed by push-fitting into a corresponding longitudinal seat formed in the fixture frame, the shape of which matches that of the base portion. While weather strips having base portions of the above described type have been widely used for several different applications, they however have highlighted some drawbacks from a pratical and operating point of view, as clarified in detail in the -following. First of all, in weather strips provided with base portions to be push-fJ tted , a true longitudinal scat suitably shaped and defined in the fixture frames is required. The above clearly involves some complexity in the cross-sectional conformation of the fixture and therefore in the manufacture and production costs of same. In addition, since a true longitudinal seat of substantially tubular conformation is to be formed in the bearing frames, many problems are encountered both in terms o-f anchoring and as regards a safe seal, for example either when discontinuities am found, due to the presence o-f locks typically disposed along the fixture perimeter, or when there are regions where sharp bendings or too acutely angled corner areas are present in the frame. In terms of installation, above all with reference to corner areas, traditional weather strips also encounter many difficulties in carrying out junctions between two consecutive strips, due to the bulged conformation of the base portions. It is also to point out that the base portions of traditional weather strips are subjected to wear in the long run and therefore tend to reduce their sealing capabilities and the capability of matching with the fixture frame. This is particularly due to the fact that this base portion, necessarily made of a deformable material, acts on and is directly in contact with the fixture frame which is usually made of materials such as aluminium, wood or PVC, that are much harder than the base portion of the strip and therefore capable of creating tearings tnd/αr abrasions on the deformable strip, taking into account the particular type of coupling existing with the frame itself. It is finally to note that, since the base portion has the dual task of ensuring anchoring and achieving the necessary hermetic tightness, an extended interference fit is required for this portion, which will make any disengagement and subsequent re-engagement of the weather strip from and into the respective seat of difficult accomplishment. Under this situation, it is a fundamental aim of the present invention to substantially solve all drawbacks mentioned above by providing a new weather strip that, on the one hand, can ensure an excellent efficiency and operating reliability and, on the other hand, is capable of being associated with fixture frames that are not necessarily provided with longitudinal tubular seats, so as to enable money to be saved in the fixture frame manufacture. In particular, it is an object of the invention to provide a weather strip having an anchoring portion capable of accomplishing a steady engagement with the fixture frame and a very reliable and durable seal even under very heavy operating conditions. It is a further object of the invention to make a weather strip capable of being easily fitted to and disengaged from a fixture frame without being subjected to structural decays. The foregoing and further objects that will become more apparent in the progress of the following description are substantially achieved by a weather strip in particular for door and window frames and the like, as claimed in the appended claims. Further features a d advantages wi11 best be understood from the detailed description of some preferred embodiments of a weather strip in accordance with the invention, taken hereinafter with the aid of the accompanying drawings given by way of non-limiting example and in which: - Fig. 1 is an enlarged cross-sectional view of the weather strip of the invention under non-operating conditions; - Fig. 2 is a cross-se ional view similar to that in Fig. 1, showing the weather strip of the invention associated with a fixture frame; and - Fig. 3 is a fragmentary and enlarged cross-sectional view of a possible alternative embodiment of the base portion of the weather strip in reference. With reference to the drawings, a weather strip in particular for door and window frames and the like has been generally identified by reference numeral 3. Weather strip - comprises a base portion 2 arr tnged for fitting at an anchoring area 3 associated with a first bearing frame, generally denoted by 4, for example of a window/door fixture. The first frame 4 can be moved from an open position (not shown) to a closed position (seen in Fig. 2) in which the weather strip conveniently performs its sealing action against external agents. It is to point out that for the purpose, the weather strip 1 is comprised of a head portion 5 .connected to the base portion and arranged to act in abutment against a rabbet area 6 of a second bearing frame generally denoted by 7 and shown in chain line in Fig. 2. Advantageously, the base portion 2 of the weather strip 1 comprises a holding element 8 of stiff or substantially stiff material such as alu injum, PVC or other appropriate material. The holdinq element 8 is arranged to carry out engagement of the anchor ing area 3 of the first bearing frame 4, and for the purpose it defines at least one undercut 9 for receiving a corresponding projection 10, in the form of an inverted L for example, provided at the anchoring area 3 of the first frame . Qperatively associated with the holding element 8 is push element 11 having at least one first end portion 11a that, under operating conditions, is arranged to act in abutment on the first frame and to transmit a corresponding thrust action to the holding element 8 so that a snap-fitting occurs between said undercut 9 and the projection 10. In greater detail, as viewed from the accompanying figures, a second end portion lib is also provided and it is cirranged in a substantially opposite position with respect to the first end portion 11a. Said second end portion lib too is intended for acting in abutment on the first frame so that, under operating conditions, it transmits a respective thrust action capable of enabling snap-fitting of the holding element 8 with the anchoring area 3. Practically, due to the arrangement of the the first and second portions, respective thrust actions are generated that are disposmd and directed in such a manner as to give rise to a resultant substantially directed perpendicularly to the contact area between the undercut 9 and the projection 10 formed on the first rame. It is to note that the push element 11 is made of an elastically deformable material so that the end portions 11a and l b, due to coupling of the weather strip 1 with the first frame 4, can be subjected to elastic deformation, thereby generating said thrust actions. From a construction point of view, it is to note that the push element 11 is perimetrically associated with the holding element 8 and is integrally coupled therewith. Preferably, connection between the push element and holding element takes place by co-extrusion which, on the one hand, enables a strong and durable coupling to be achieved and, on the other hand, offers the possibility of adopting a continuous manuf cturing process, which will bring about very reduced production costs. As can be seen from Figs. 2 and 3, by their deformation the first and second end portions not only give rise to the required thrust actions for coupling of the holding element 8 with the first frame, but also ensure creation of efficient sealing areas lie, lid impervious tn air, water and still other agents. More particularly, in order to improve the insulating capability to external agents, the first end portion lla can be provided with a turned-up sealing end lip 12, as shown in the embodiment illustrated by way of example in Fig. 2. Although weather strips of a co for ation as above described offer a good seal capability under normal operating conditions, it is to note that in the presence of particularly heavy situations, in case of strong rainfalls and concurrent gusts of wind for example, employment of an auxiliary sealing element 13 coupled with an operating surface 14 of the holding element 8 facing the projection 10 of said anchoring area has appeared as very efficient. More particularly, the auxiliary sealing el ment 13 comprises at least one narrow band of sealing material longitudinally associated with the holding element and extending close to a hollow space 15 that, when the base portion 2 is coupled with the anchoring area 3, is defined between said projection 10 and op ra ing surface 14 of the holding element 8. As regards its accomplishment, the sealing narrow band defining the auxiliary sealing element can be made either of butyl or sili one materials or still other materials capable of undergoing deformation for ensuring the necessary seal, and in particular capable of offering softness features maintained substantially constant in time, so that the weather strip performance does not decay with use. Still with reference to the auxiliary sealing element 13, it is to note that the choice of the material is to be made taking into consideration the fact that the adhesion force between the auxiliary element and the holding element must be higher than the adhesion force that, under operating conditions, will take place between the auxiliary sealing element itself and the anchoring area of the first frame. This is essential, because otherwise phenomena of partial or complete gluing between the auxiliary sealing element and the first frame 4 would occur. Actually, in case of gluing, each time the weather strip needs to be removed, due to breakings or merely when servicing is required, tiresome operations for cleaning the frame and restoring the auxiliary sealing element on the weather strip 1 would be necessary. From a construction point of view, the scaling narrow band of butyl or other material is associated, for example by a continuous extrusion process, with the holding element 8, after said holding element has been fixedly joined to the push element 11. In other words, as regards production, first the holding element 8 is co-extruded with the push element 11, then the two coupled elements are allowed to cool in order to make their union stable and subsequently continuous application of the sealing narrow band is carried out. The invention achi ves important, advantages:. It is to note first of all that, by virtue of the new con ormation of the base portion 2 provided in the weather strip in reference, door and window frames devoid of the conventional longitudinal seats of tubular form can be made. This ensures a cheaper production of the section members, which will bring about a clear advantage in the overall costs of the door/window fixtures. It should be also recognised that the base portions 2 in the weather strip in reference can be easily joined to each other even at the corner areas or areas with sharp bendings because these portions are in any case defined by open profiles that are easily connectable. In addition to the above, the weather strip in question is advantageously capable of ensuring an optimal seal under any (even if very heavy) operating conditions, due to the presence both of the end portions lla and lib and the sealing narrow band 13 associated with the holding element. Furthermore, the described weather strip is very reliable in time because that part of the base portion 2 that is directly in contact with the window/door frame, that is the holding element 8, is made of a material having mechanical features very close to those of the frame itself, thereby avoiding arising of tearings and/or abrasions in the long run. In conclusion, it i apparent from the above that, since in the weather strip in question the sealing and anchor ng functions are distinct and epar ed from each other, the former being assigned to the contact areas of the end portions lla and lib with the frame and to the sealing narrow band 13, and the latter being assigned to the holding element 8, the greatest efficiency can be achieved by the invention as regards both anchoring and seal, and said weather strip can be easily fitted and disengaged and can offer performances substantially constant in time. It is to point out furthermore that also the position of the narrow band 13 in the hollow space 15 is advantageous, taking into account the fact that said narrow band is required to be deformed for accomplishing the appropriate sealing action and also for enabling snap-fitting between the holding element 8 and the projection 10. To this end, the choice of the materials forming the narrow band 13 is undamental too, because they must be of appropriate softness and possess a high adhesion capability to the holding element but a weak tendency to stick on the fixture frame. It is understood that modifications and variations can be made to the invention as conceived, all of them falling within the scope of the appendend claims.

Claims: C L A I S 1. A weather strip, in particular for door and window frames and the li e, comprising: - a base portion (2) arranged for fitting at a respective anchoring area (3) of a first bearing frame (4) ; - a head portion (5) connected to said base portion (2) and such arranged as to act in abutment on a rabbet area (6) of a second bearing frame (7) , characterized in that said base portion (2> comprises: - a holding element (8) adapted to carry out engagement of said anchoring area (3) of the first bearing frame (4); and - a push element (11) operatively associated with the holding element (8) and having at least one first end portion (lla) intended for acting, under operating conditions, in abutment on said first frams (4) and transmitting a corresponding thrust action to the holding element (8) to cause snap-fitting with said anchoring area (3). 2. A we tther strip as claimed in claim 1, characterized in that said holding element (8) defines at least one undercut (9) receiving in engagement a corresponding projection (10) formed at the anchoring area (3) of said first frame (4). 3. A weather strip as claimed in claim 1, characterized in that said push element (11) is perimetrical ly associated with said holding element. 4. A weather strip as claimed in claim 1, characterized in that the push element (11) is integrally coupled with said holding element (8). 5. A weather strip as claimed in claim 4, characterized in that the push element (11) is coupled with the holding element (8) by co-extrusion. 6. A weather strip as claimed in claim 1, characterized in that said push element (11) has a second end portion ( lib ) disposed at a substantially opposite position with respect to said first portion (lla) and also intended for acting, under operating conditions, in abutment on said first frame (4). 7. A weather strip as claimed in claim 1, characterized in that said push element (11) is made of elastically deformable material. 8. A weather strip as claimed in claim 1, characterized in that said holding element (8) is made of a substanti lly stiff material. 9. A weather strip as claimed in claim 1 , characterized in that. said base portion (2) further comprises an auxiliary sealing element (13) coupled with an operating surface (14) of the holding element (8) facing the projection (10) of said anchoring area (3). 10. A weather strip as claimed in claim 9, characterized in that said auxiliary sealing element (13) comprises at least one narrow band of sealing material longitudinally associated with said holding element. 11. A weather strip as claimed in claim 10, characterized in that said narrow band extends within a hollow space (15) that when the base portion (2α is operativεly coupled with the anchoring area (3) is defined between said projection (10) and the operating surface (14) of the holding element (8). 12. A weather strip as claimed in claim 10, characterized in that said sealing narrow band (13) is made of a material having softness features thak keep constant in time. 13. A weather strip as claimed in claim 1, characterized in that at least said first end portion (lla) is provided with a turned-up sealing end lip (12).

Inventors: CALDIROLI ALFONSO, CITTADINI PAOLO, CALDIROLI, ALFONSO, CITTADINI, PAOLO
Applicants: CALDIROLI ALFONSO, CITTADINI PAOLO, ILPEA IND SPA, CALDIROLI, ALFONSO, CITTADINI, PAOLO, INDUSTRIE ILPEA S.P.A.
Application year: 1996
Main classification: E06B7
IPC codes: B60J10, E06B7