Rear door structure for a vehicle

A door structure for a vehicle has a door seated in a door jam frame at the rear end of the vehicle. The door jam fame has a first upright with an opening therein disposed nearby one side of the vehicle to provide a space between this side and the first upright. A second upright is nearby the other side of the vehicle. A hinge member is attached to the door which includes a first connecting member attached to the door member near the one side of the vehicle, a second connecting member pivotally attached to the first upright and disposed in the space between the one side of the vehicle and the first upright, and an intermediate arcuate member connected between the first and second connecting members which extends through the opening in the first upright.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 This invention relates to a door structure for the rear end of a vehicle
 such as, for example, a hearse.
 2. Background Discussion
 Some vehicles, in particular hearses, use a rear door that is mounted to be
 opened to the left or right, rather than being lowered and raised to open
 and close. It is desirable to provide such a door which is lightweight yet
 sturdy, and incorporates many of the desirable features of modern vehicles
 such as automatic closing mechanisms commonly provided on trunks of
 automotive vehicles. It is also desirable to provide a hinge mechanism
 which is reliable, easy to install, low cost to manufacture, and which has
 an attractive appearance. It is the objective of this invention to provide
 a door structure with these desirable attributes.
 SUMMARY OF THE INVENTION
 This invention has several features, no single one of which is solely
 responsible for its desirable attributes. Without limiting the scope of
 this invention as expressed by the claims which follow, its more prominent
 features will now be discussed briefly. After considering this discussion,
 and particularly after reading the section entitled, "DETAILED DESCRIPTION
 OF THE PREFERRED EMBODIMENT," one will understand how the features of this
 invention provide its benefits, which include low cost, simplified
 manufacture, reliability, and a streamline hinge appearance.
 The first feature of the door structure of this invention is that it is
 particularly designed to be mounted at an open rear end of a vehicle, such
 as a hearse, between the opposed sides of the vehicle. It includes a door
 member, preferably having exterior and interior spaced apart wall members
 made of a light weight, polymeric material. A honeycomb reinforcing member
 is positioned between the wall members, and a mounting plate made of metal
 is secured to the interior wall in a position to be nearby one side of the
 vehicle when the door member is attached to the open rear end of the
 vehicle.
 The second feature is that the door structure includes a door jam frame at
 the rear end of the vehicle in which the door member is seated when closed
 and from which said door member extends when opened. The door jam fame has
 a first upright disposed nearby the one side of the vehicle to provide a
 space between this one side of the vehicle and the first upright. A second
 upright nearby the opposite side of the vehicle. A hinge member is
 attached to the mounting plate and extends through an opening in the first
 upright.
 The third feature is that the hinge member has a first connecting member
 attached to the mounting plate, a second connecting member pivotally
 attached to the first upright and disposed in the space between the one
 side of the vehicle and the first upright, and an intermediate arcuate
 member connected between the first and second connecting members which
 extends through the opening in the first upright. The first connecting
 member is substantially planar. The second connecting member is also
 substantially planar and is at an angle in excess of 90 degrees with
 respect to the second connecting member, preferably from about 120 to
 about 130 degrees. The intermediate arcuate member has a substantially
 smooth, continuous, external surface. Such a surface provides an
 attractive, streamline appearance. Preferably, the arcuate member is a
 segment of a cylindrical wall. The axis of rotation of the hinge member is
 the centerline of the cylinder from which the cylindrical wall segment is
 taken. In other words, the centerline of the segment of the cylindrical
 wall is coincident with the axis of rotation of the hinge member. The
 hinge member pivots around this centerline as the door member is opened
 and closed. There are walls adjacent the hinge member which are covered
 with a decorative material. These walls are positioned so that only the
 arcuate member of the hinge is exposed as the door is opened and closed.
 The fourth feature is that a mounting member is attached to the door jam
 frame in a fixed position in the space between the one side of the vehicle
 and the first upright. This mounting member has a cam surface thereon,
 with a portion which acts to hold the door member in an open position when
 engaging a cam follower. The hinge member has a cam follower attached to
 it. This cam follower, when the door member has been partially opened,
 engages the cam surface, and, when the door member has been opened to a
 predetermined maximum open position, it engages the stop to hold the door
 member in the predetermined maximum open position.
 The fifth feature is a latch mechanism attached to the door member. The
 exterior wall member has a handle member therein near the opposite side of
 the vehicle which, when activated, engages and disengages the latch
 mechanism. A striker mechanism is provided having a motor which pulls the
 door into the door jam frame when the latch mechanism initially contacts
 the striker mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 As illustrated in FIGS. 1a and 1b, a hearse 10 is equipped with the door
 structure 12 of this invention, which includes a door 14 mounted by a
 hinge 16 to the left side of the hearse so that the door can swing to
 towards the left side of the hearse upon being opened. When closed, the
 door 14 fits snugly within a door jam frame 18 located in the open rear
 10a of the hearse 10, as illustrated in FIG. 1a. The door 14 optionally
 could be mounted to the right side of the hearse 10 so that it would swing
 to the right upon being opened.
 As shown in FIG. 1b, 3, and 5 through 7, the door 14 includes an interior
 wall 14a and an exterior wall 14b, preferably made of a lightweight,
 durable, composite material, such as a polymeric material like fiberglass.
 A honeycomb reinforcing member 20 is disposed between the interior and
 exterior walls 14a and 14b to provide structural rigidity to the door 14.
 There may be openings in the door 14 such as a window 22 (FIGS. 1a and
 1b), and the entire area between the interior and exterior walls need not
 be filled completely with the honeycomb reinforcing member 20. A marginal
 end wall 14c surrounds the honeycomb reinforcing member 20, providing an
 enclosure for the honeycomb reinforcing structure. A generally square
 shaped, metal mounting plate 24 is imbedded inside the door 14, forming a
 part of the interior wall 14a. An epoxy resin adhesive may be used to
 secure this metal mounting plate 24 in position adjacent the left side of
 the hearse 10, to which the door 14 is connected.
 The door jamb frame 18 has a top 18a and a bottom 18b, and opposed left and
 right uprights 18c and 18d, respectively. Both the left and right uprights
 18c and 18d are spaced inwardly from the sides of the hearse 10 to
 provide, respectively, the spaces 28c and 28d. As best illustrated in
 FIGS. 5 through 7, the space 28c is between the left side of the hearse 10
 and the upright 18c and the space 28d is between the right side of the
 hearse 10 and the upright 18d. The left upright 18c is covered with a
 decorative cover 19.
 As best shown in FIGS. 9 and 10, the left upright 18c to which the hinge 16
 is attached has cutaway sections that provide openings 30 and 32 that
 allow the hinge 16 to move through these openings as the door 14 is opened
 and closed. An extension section between these openings 30 and 32 provides
 a mounting plate 34 for a cam mechanism 36 which is attached to this plate
 as illustrated in FIGS. 5 through 7. A cam wheel 40 mounted on a bracket
 40a carried by the hinge 16 engages the cam mechanism 36 as the door is
 closed as discussed subsequently in greater detail. The mounting plate 34
 is bend inward towards the left side of the hearse 10, so that it is
 disposed in the space 28c. A stop 38 is formed in this upright 18c in its
 lower portion. This stop 38 engages the hinge 16 member when the door 14
 is in its maximum open position, as shown in FIG. 1a and in dotted lines
 in FIGS. 5 and 10.
 As best depicted in FIGS. 8 and 9, the hinge 16 is a unitary, piece of
 metal, preferably steel, having a generally flat planar connecting member
 16a attached by hinge pins 46 inserted into triangular shaped mounting
 brackets 48 secured by bolts to the left upright 18c on the inside of this
 upright in the space 28c, respectively at the top and bottom of this
 upright. A second, generally flat planar connecting plate 16b is bolted to
 the mounting plate 24. The two connecting plates 16a and 16b are disposed
 relative to each other at an angle A greater than 90 degrees, preferably
 at an angle of 125 degrees. These two connecting plates 16a and 16b merge
 with an arcuate member 16c of the hinge 16. This arcuate member 16c has a
 solid, smooth, continuous, exposed surface S that has an attractive
 appearance when the door 14 is opened, as illustrated in FIG. 1b. This
 arcuate member 16c is a segment of a cylindrical wall where the centerline
 C of the cylinder is coincident with the axis of rotation of the hinge 16.
 As illustrated in FIG. 5, the walls 50 and 52 of the rear loading section
 10b of the hearse 10 are adjacent this arcuate member 16c. The wall 50 is
 attached to the left inside of the rear loading section 10b, and the wall
 52 is attached to the interior wall 14a of the door 14, and moves with the
 door. These walls 50 and 52 are covered with a decorative material and
 spaced apart to provide a relatively narrow gap 56, which increases and
 decreases in width as the door 14 is opened and closed. Regardless of the
 position of the door 14, the gap is nevertheless restricted in width, so
 that only the smooth, continuous, surface S is exposed to view.
 As best shown in FIG. 8, the connecting member 16a has centrally located
 therein an enlarged, square opening 60. The bracket 40a for cam wheel 40
 is attached to this connecting member 16a and the cam wheel is positioned
 at the square opening 60 so that, when the door 14 is partially opened,
 this cam wheel will engage the cam mechanism 36. As best shown in FIG. 7a,
 the cam mechanism 36 includes a cam surface 36a over which the wheel 40
 rides until it comes to an indentation 36b. The cam surface 36a is the
 exterior of a leaf spring that has a ramp 36c attached at one end to a
 bracket 36d which is bolted by bolts (not shown) passing through a slot 35
 in the mounting plate 34. The ramp 36c leads to the indentation 36b. A
 rubber block 66 is disposed between the bracket 36d and the underside of
 the indentation 36b. Thus, when the cam wheel 40 rides up the ramp 36c and
 drops into the indentation 36b, it will remain in this position, holding
 the door 14 in its maximum opened position until the door is manually
 closed.
 As best shown in FIGS. 4a and 4b and 5 through 7, there is a handle 70 in
 the exterior wall of the door 14 which, upon being lifted upward open the
 door 14 by disengaging a conventional latch mechanism 72 from a motor
 driven striker 74, enabling the door 14 to be opened. This handle 70 is
 attached to a rod 76 mounted at its ends so that it may rotate. A bent
 connecting member 78 mechanically couples this rod 76 to the latch
 mechanism 72, with one end of the bent connecting member attached by a bar
 80 to the latch mechanism, and the other end of this bent connecting
 member attached by another bar 82 to the rod 76. Because of this
 mechanically coupling, lifting the handle 70 as shown in FIG. 7 disengages
 the latching mechanism 72 from the striker 74, enabling the door 14 to be
 opened. A spring 84 coiled around the rod 76 returns the handle 70 to its
 normally closed position, as shown in FIG. 6. When the door 14 is closed,
 as soon as the latching mechanism 72 engages the striker 74, a motor 88 is
 activated to pull the door 14 completely and automatically within the door
 jam frame 18. Such latching mechanisms 72 and striker 74 are commonly
 employed in trunks of automotive vehicles, but are not ordinarily used on
 a door 14 which require a handle that is manually manipulated.
 SCOPE OF THE INVENTION
 The above presents a description of the best mode contemplated of carrying
 out the present invention, and of the manner and process of making and
 using it, in such full, clear, concise, and exact terms as to enable any
 person skilled in the art to which it pertains to make and use this
 invention. This invention is, however, susceptible to modifications and
 alternate constructions from that discussed above which are fully
 equivalent. Consequently, it is not the intention to limit this invention
 to the particular embodiment disclosed. On the contrary, the intention is
 to cover all modifications and alternate constructions coming within the
 spirit and scope of the invention as generally expressed by the following
 claims, which particularly point out and distinctly claim the subject
 matter of the invention: