Patent Abstract:
A doorstop with at least three cushions on its upper surface. Two male protrusions extend from the lower surface to facilitate assembly to a vehicle.

Full Description:
SUMMARY OF THE INVENTION  
       [0001]     According to the invention there is provided a doorstop having at least three cushions on an upper surface thereof and at least two male protrusions extending in a direction away from said cushions and spaced apart in a direction along a longitudinal axis of said doorstop.  
         [0002]     In one embodiment there is provided a doorstop comprising two housing parts each of approximately trapezium shape and each having three cushions on the upper surface thereof and a threaded male protrusion extending in a direction away from said bumpers on said respective housing part and spaced in a direction away from said cushions on said respective housing part and spaced in a direction along a longitudinal axis of the housing part from said bumpers.  
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0003]     Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which:  
         [0004]      FIG. 1  shows a doorstop from U.S. Pat. No. 6,842,943 in a sectional side view;  
         [0005]      FIG. 2  is a plan view of a doorstop according to one embodiment of the present invention;  
         [0006]      FIG. 3  is a perspective view of the two parts forming the doorstop of  FIG. 2  opened up for clarity purposes.  
         [0007]      FIG. 4  is another view of the two parts forming the doorstop of  FIG. 2  opened up for clarity purposes.  
         [0008]      FIG. 5  is a perspective view of a doorstop of approximately rectangular cross-section;  
         [0009]      FIGS. 6 and 7  illustrate other parts for use with the doorstop part of  FIG. 5 ;  
         [0010]      FIGS. 8 and 9  illustrate a further embodiment of the invention; and  
         [0011]      FIGS. 10 and 11  illustrate a yet further embodiment.  
     
    
     DETAILED DESCRIPTION  
       [0012]      FIG. 1  shows a sectional side view of a doorstop, as illustrated in U.S. Pat. No. 6,842,943, the plane of section running through the doorstop parallel to the pivot axis and the door retaining rod  1  passing though the retaining piece  2 . At its bottom end in the figure, the door-retaining rod  1  has a bearing eye  6  and at the other end an abutment  9 . The door-retaining rod  1  is constructed from a metal core  7 , for example a flat steel section, which is covered with plastic. The plastic covering  8  is applied with different thicknesses over the length and forms bulges in the form of local thickenings, which form the brake ramps  4  and the catch depressions  5  between the bulges. In the exemplary embodiment shown, the abutment  9 , which forms the limit stop corresponding to the open position of the door, is of integral T-shaped design. The abutment  9  or the limit stop may also be alternatively formed by a pin, which is arranged through a corresponding opening in the door retaining rod  1  in the direction of the pivot axis. The brake ramps  4  and the catch depressions  5  are formed on the sides of the door-retaining rod facing the pivot axis. In the position shown the brake and/or stop bodies  3  bear bilaterally preloaded against catch depressions. The door-retaining rod  1  is led through the opening  13  in the housing  10 . The brake and/or stop bodies  3  are guided in guide openings  25  arranged perpendicular to the opening  13 .  
         [0013]     The brake and/or stop bodies  3  take the form of hollow cylinders, which are sealed at one end by a semi-spherical cap  14 . In their open end they accommodate a pressure spring  12  resting on the closing cap  14 , the spring being supported on a side wall of the housing  10 . The end faces of the housing  10  are enclosed by U-shaped metal frames  11 , which also constitute the supporting wall for the pressure springs. The brake and/or stop bodies  3  have a central bore  16  accessible from their cylindrical cavity  15  and further bores  17  arranged in a circle around this. The shape and arrangement of the bores  16  and  17  permit approximately equal wall thicknesses in the semi-spherical cap  14 . The semi-spherical cap  14  is truncated at its front end. The approximately equal wall thicknesses provide an advantageous prerequisite for manufacturing the brake and/or stop bodies from plastic by the injection molding process. In its cylindrical part  19  the outer wall of the brake and/or stop bodies  3  is fluted in the direction of movement, thereby on the one hand ensuring a favorable distribution and transmission of slide lubricants and on the other reducing the bearing surface of the cylindrical part  19  on the inner surface of the guide opening  25  and hence frictional forces occurring when the brake and/or stop bodies  3  slide in the guide opening  25 .  
         [0014]     Cushions  22  of an elastic material are integrated into the upper end surface  20  of the housing  10 , against which cushions the abutment  9  resiliently strikes when the door is in the open position. Fixing apertures  21  are arranged in the bottom end surfaces of the metal frames  11 . In the exemplary embodiment shown these have an internal thread for fixing the retainer piece to a door assembly piece by means of threaded screws. Press-on screws, not shown here, can also be used for fixing, however. It will be obvious that in the embodiment of the housing  10  and metal frame  11  shown there is a high degree of flexibility in the choice of hole spacing and hence in the hole piercing variants.  
         [0015]     The present invention is concerned with a doorstop, or door closure housing, which offers advantages over that shown in the above-identified U.S. patent.  
         [0016]     Referring to  FIGS. 2, 3  and  4 , the doorstop is made of two similar housing parts  30  and  32  of approximately trapezium shape in cross-section. A total of six stop cushions  34  of elastic material are integrated into the upper surfaces of the housing parts  30  and  32 , three on each plastic housing part. This number of cushions  34  is a substantial non-obvious improvement over previous arrangements and permits the accommodation of more “head” configurations than previously accomplished. Even only a total of four cushions  34  were found to be advantageous, although six were better. It is a cost saving as well, over putting the cushions on a link arm.  
         [0017]     The two housing parts fit together with an aligning or “locking” mechanism comprising two round male/female bushings  36  and  38 . It has been found that this tends to overcome a matching and stacking problem.  
         [0018]     A male threaded stud  40  is provided on each housing part  30  and  32  to facilitate assembly to a vehicle by a customer.  
         [0019]     The parts of the housing can conveniently be produced by using a sonic welding procedure. This would appear to result in a saving of costs for two rivets and should save integrity and time.  
         [0020]     It will be understood that the frame in the housing according to the present invention is all plastic whereas in the above-identified U.S. patent the frame  11  is a U-shaped metal frame.  
         [0021]     In some arrangements the housing parts may be offset.  
         [0022]     It will be understood that injection moulding may be utilised and the parts may be run on vertical or horizontal machines. It is anticipated that multi-cavity molds may be used. Shrink and warp behaviour in insert moulding due to the size of the product is expected. Control of the process characteristics, such as mold temperatures, injection speeds and pressure is required. Proper drying of the material is required. Co-injection and/or over moulding can also be used to manufacture the product.  
         [0023]     It will be also understood that, the fabrication technology used may be suitable for the formation of large, long-fibre-reinforced structural thermoplastic parts.  
         [0024]     Another embodiment of the present invention is shown in  FIGS. 5-7 . In  FIG. 5  it will be seen that the doorstop  50  is of rectangular shape in cross-section and has two studs  52  and  54  in an appropriate location. As will be appreciated studs  52  and  54  may be threaded or un-threaded. These studs are moulded in the base of doorstop  50  which has a central aperture  56  where by a link arm assembly can be inserted.  
         [0025]     To close the top of doorstop  50  two panels  66  and  68  ( FIGS. 6 and 7 ) are used. These are each of a dimension to cover half the top of doorstop  50  and close the top apart from rectangular apertures  62  and  64 . The two half panels  66  and  68  are moulded with cushions, i.e. bumpers, and when completed by either heat or electrosonic “staking” will form an enclosed top as in  FIG. 5 .  
         [0026]      FIG. 8  illustrates a further embodiment in which the side  70  of the rectangular doorstop  72  is open. Again two studs are moulded into place.  
         [0027]     The side is closed by a right-angle shaped moulded plastic part, as in  FIG. 9 , with over moulded soft rubber “bumpers” on the sides of the angle-shaped plastic parts. It is assembled by means of either heat staking or ultra-sonic welding to the rectanguloid part  72 .  
         [0028]     In a yet further embodiment the rectanguloid plastic part  76 , in  FIG. 10 , is moulded with a rectangular cushion or bumper made of a rubber-like material. The bottom or base is open and a moulded plastic plate  78  ( FIG. 11 ) with two studs is joined to part  76  by means of either heat staking or ultrasonic welding.  
         [0029]     Having thus described the invention in detail, it is to be understood that the foregoing description is not intended to limit the spirit and scope thereof. What is desired to be protected by Letters Patent is set forth in the appended claims.

Technology Classification (CPC): 4