Abstract:
A laterally movable wiper arm assembly cleans curved interior surfaces of automobile and truck windshields. The wiper blade is movable on two curved tracks; one at the top of the windshield and one at the bottom of the windshield, with a vertically oriented telescoping wiper blade movable laterally therebetween. The telescoping arm support permits the vertical blade to tilt into the corners at the bottom of the windshield, to cover a larger proportion of the area, since the bottom of a windshield is longer than the top. The blade or wiping pad is supported with a resilient foam layer attached to a flexible substrate, which is adjustably attached to a rigid support arm following the windshield contour.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a windshield wiper for the inside of an automobile windshield. 
     BACKGROUND OF THE INVENTION 
     Various devices are known for cleaning both sides of a window, such as an automobile windshield. 
     U.S. Pat. Nos. 4,023,422 of Jou, U.S. Pat. No. 5,105,501 of Douglas and U.S. Pat. No. 1,689,214 of Small all describe devices which clean the interior of a vehicle windshield. 
     However Jou ′422 requires a complicated joining pivoting apparatus under the windshield to move the exterior and interior wipers simultaneously. Douglas ′501 uses magnets to pull the interior wiper by means of the outer wipers motive force and Small ′214 uses radially pivoting wipers on a flat, old fashioned windshield, not a laterally movable wiper blade crossing a concave interior surface of a windshield. U.S. Pat. No. 5,515,570 of Muscroft also describes a magnetic, two-sided window cleaner. 
     Window cleaners with a wiper movable on a pair of parallel tracks, are described in devices which clean flat rear view mirrors, especially for trucks, as in U.S. Pat. Nos. 3,866,258 of DeGraw and U.S. Pat. No. 4,212,091 of Jones. U.S. Pat. No. 1,338,002 of Derry uses tracks for cleaning flat windows. 
     However, because of variations in windshield height in the middle as opposed to the side corners, the aforementioned devices for cleaning flat surfaces cannot clean curved interior surfaces of automobile and truck windshields. 
     OBJECTS OF THE INVENTION 
     It is an object of the present invention to provide a windshield wiper for the inside of an automobile windshield. 
     It is also an object of the present invention to provide a devices are known for cleaning both sides of a window, such as an automobile windshield. 
     It is also an object of the present invention to provide a because of variations in windshield height in the middle as opposed to the side corners, the aforementioned devices for cleaning flat surfaces cannot clean curved interior surfaces of automobile and truck windshields. 
     It is also an object of the present invention to provide a for a motorized version and one for a manually sweepable version. The wiper blade is movable on two curved tracks; one at the top of the windshield and one at the bottom of the windshield, with a vertically oriented wiper blade movable laterally therebetween. 
     It is also an object of the present invention to provide a motorized version and one for a manually sweepable version. The wiper blade is movable on two curved tracks; one at the top of the windshield and one at the bottom of the windshield, with a vertically oriented wiper blade movable laterally therebetween. 
     It is also an object of the present invention to provide a motorized version and one for a manually sweepable version. The wiper blade is movable on two curved tracks; one at the top of the windshield and one at the bottom of the windshield, with a vertically oriented wiper blade movable laterally therebetween. 
     It is also an object of the present invention to provide a some telescoping to the wiper arm support. 
     It is also an object of the present invention to provide a minimize any impediment to driver peripheral view. 
     It is also an object of the present invention to provide an aftermarket kit to be installed by a car or truck owner. 
     It is also an object of the present invention to improve over the disadvantages of the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention is a laterally movable wiper arm assembly for cleaning curved interior surfaces of automobile and truck windshields. 
     The present invention includes two embodiments: one, for a motorized version and one for a manually sweepable version. The wiper blade is movable on two curved tracks; one at the top of the windshield and one at the bottom of the windshield, with a vertically oriented wiper blade movable laterally therebetween. 
     A key important detail is that in order to accommodate the fact that some windshields are shortest in the middle and widest at the side corners or vice-versa, there has to be some telescoping to the wiper arm support. 
     Another reason for the telescoping arm support is to permit the essentially vertical blade to tilt into the corners at the bottom of the windshield to cover a larger proportion of the area since the bottom of a windshield is longer than the top. 
     Special attention is given to the problem of maintaining contact with the concave inside surface of the windshield. The blade or wiping pad is supported with a resilient foam layer attached to a flexible substrate which is adjustably attached to a rigid support arm in such a manner as to follow the windshield contour. 
     The windshield wiper mechanism is designed so that the arm is always parked at the passenger side when not cycling. This is to minimize any impediment to driver peripheral view. By being at the opposite end of the windshield, the wiper blade assembly simply merges into the windshield pillar from the driver&#39;s viewpoint. 
     A manually operable device uses a handle. 
     This invention is described in detail as an aftermarket kit to be installed by a car or truck owner. It is obvious that a similar function can be served by a factory-installed option on a new vehicle. 
     The same general features and design would be applicable, however minor details such as mounting hardware and track construction can be modified to reduce part cost and installation labor by professionals at assembly time since these details would apply to a custom design for a specific vehicle model. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention can best be understood in connection with the accompanying drawings, in which: 
     FIG. 1 is an Interior front elevation view showing the wiper of this invention in various positions on the windshield; 
     FIG. 2 is a Side view with the windshield shown in cross section; 
     FIG. 3 shows Top and side views of the various parts of an after market embodiment for an installation kit of the present invention; 
     FIG. 4 is a Perspective view of the drive components thereof; 
     FIG. 5 is a Circuit diagram for a motorized embodiment of the present invention; 
     FIG. 6 is a Circuit diagram of the timer feature thereof; and, 
     FIG. 7 is a Side view with the housing shown in cross section of an alternate embodiment for a manual drive module. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Since the interior wiper of this invention should only encounter mist, very little pressure against the windshield is required. While a conventional rubber wiper blade can be used, equally effective is an absorbent fabric pad configured into a narrow blade-like shape. With little pressure there is consequently little frictional drag against the windshield. Furthermore, with judicious attention to drive line friction, lightweight components and modest power requirements are the resulting design parameters. 
     FIG. 1 is an interior view of a typical windshield  2  with the wiper assembly  1  of this invention in various positions along its cyclic motion. Part  3  is the telescoping extension. Wiper assembly  1  rides in top track  4  and bottom track  5 . Track  5  is approximately 25 percent longer than track  4  for a typical windshield. In position  6  at the center, wiper  1  is vertical. As wiper  1  goes right to position  7 , wiper  1  starts to tilt out (angle A) and wiper  1  pivots slightly both at the top and bottom. At the end of the stroke to the right at position  8 , wiper  1  is tilted to its maximum angle B. Similarly, at positions  9  and  10 , wiper  1  tilts in the opposite direction (angles C and D) to cover most of the windshield area. 
     The side view of FIG. 2 reveals some of the details that insure intimate contact of wiper blade pad  20  with the concave inner surface of windshield  2 . A portion  22  of the vehicular hood is shown. Blade pad  20  is attached to a layer  20  of resilient foam, which conforms to minor concavity variations as wiper  1  moves across windshield  2 . Attachment tabs  21  on flexible semi-rigid substrate  18  are adjusted through screw attachment to rigid wiper support  17  so as to optimize the contour to match windshield  2  concavity at mid stroke. Arched shape  23  provided between rigid wiper support  17  and semi-rigid substrate  18  results from this adjustment. 
     FIG. 3 shows the various parts that make up an installation kit of this invention. Standoffs  16  shaped like short I-beam sections are used to mount bottom track  5  spaced a small distance away from windshield  2  surface (as in FIG. 2) to minimize interference with the flow of defrosting air from the vehicle system. An alternative attachment (not shown) is to dashboard surface  15 . Surfaces  52  of standoffs  16  are covered with adhesive patches to facilitate attachment of bottom rail  5  with u-shaped cross section after it is cut to size. Upper rail  4  with u-shaped cross section is cut to size and is adhesively bonded to the inner surface of windshield  2  using high bond “double sticky” foam core tape. A side view of blade subassembly  48  shows a better view of the contour adjusting slots in tabs  21 . These are attached to the sides of rigid wiper support  17  with screws (not shown). 
     Telescoping extension  3  is attached to top track plate  30  with two wheels at pivot point  31 . Compression spring  35  fits in cavity  34  and insures that support bar  17  is in intimate track guidance contact at all times by providing force against top rail  4  and bottom rail  5 . 
     Bottom track plate  32  with two wheels is attached to support  17  at pivot point  33 . Two timing belt segments  38  and  39  to be trimmed to fit are included. Timing belt idler pulleys  49  and  50  are mounted to the track ends at the driver side with brackets (not shown). 
     Telescoping drive shaft  40 , which is non-circular cross section, is attached to a top timing belt drive pulley  41  and a bottom timing belt drive pulley at least  20  percent larger in effective diameter. Drive shaft  40  typically has hexagonal or square cross sectional tubing sections. The telescoping feature of shaft  40  is used to accommodate windshields of a large variety of cars and trucks, which differ significantly in nominal height. DC permanent magnet (PM) gear motor  43 , limit switches  44  and  45 , push button  47 , reversing relay  46 , and diode  51  are the electrical components. 
     FIG. 4 shows the drive configuration. Drive motor  43  and shaft  40  are placed at the passenger side of the windshield while respective idler pulleys  49  and  50  for respective belts  38  and  39  are at the driver end. Attachment point  55  of belt  38  is attached to and drives top plate  30  while attachment point  56  is attached to and drives bottom plate  32 . 
     The use of timing belts and pulleys and top and bottom drive through telescoping shaft  40  insures synchronism of the drive system with no chance of slippage. Larger pulley  42  drives belt  39  a greater distance than belt  38  with each motor  43  revolution. Belts  38 ,  39  are attached and adjusted at midstroke with wiper assembly  1  in a vertical position. Deviations from the center in either direction tilt wiper assembly  1  in the desired direction to tilt into the bottom corners of the windshield to wipe. 
     Limit switch  44  is mounted to detect the arrival of wiper assembly  1  at the end of the stroke at the driver&#39;s side. Relay  46  is used for motor reversal and limit switch  45  is used to detect the arrival of the wiper assembly  1  at the passenger side. 
     FIG. 5 shows a schematic diagram of the electrical subsystem. In operation, wiper  1  is parked at the passenger side. The driver presses push button  47  for about at least a half second but not longer than three seconds. An automatic sequence commences with wiper  1  sweeping across to the end of the stroke at the driver side, then reverses direction and sweeps all the way to the passenger side, then shuts down. 
     The circuit operates as follows. Plug  60  is provided to operate the wiper accessory from the cigarette lighter outlet; direct connection to accessory terminals under the dashboard is an alternative. Fuse  61  is a safety feature. With coil  62  of relay  46  de-energized, motor  43  is connected so as to move wiper assembly  1  toward the driver. Direct current (DC) permanent magnet (PM) motors reverse direction when the polarity of the supply current is reversed. 
     At the start of the cycle, relay  46  is de-energized and normally closed limit switch  45  is open because wiper  1  is physically against it. When momentary push button  47  is closed for a short interval, power flows through de-energized relay  46  contacts through switch  47  and motor  43  starts to turn moving wiper  1  away from limit switch  45 . Limit switch  45  reverts to its normally closed state and now creates a current path to motor  43  even after push button  47  is released. 
     Motion continues toward the driver until limit switch  44  (which is normally open) is closed by having contact with wiper assembly  1 . This energizes relay  46  via coil  62 , which immediately reverses direction of motor  43 . When motion reverses, driver side limit switch  44  soon opens as wiper assembly  1  moves away, but relay coil  62  is maintained in the powered state through a tap at a motor terminal and a path through diode  51 . Thus motor  43  continues toward the passenger side until limit switch  45  is “bumped”. This interrupts current to the motor and coil  62  simultaneously shutting down the system and preparing the relay  46  contacts for motion in the opposite direction the next time push button  47  is pressed. Diode  51  is required to prevent a short circuit when limit switch  44  is first tripped prior to motor reversal. 
     The circuit just described provides a single back-and-forth wiper cycle for each short press of the momentary push button. 
     If automatic repetitive cycles are desired, the timer circuit of FIG. 6 can be used as a substitute for push button  47 . It is wired in at points P and M and X X of FIG.  5 . It is assumed that continuous operation of an interior wiper is not required. Therefore the minimum interval of timer  70  is longer than the back-and-forth cycle duration. 
     An adjustment knob  71  is provided to adjust electronic timer  70  from a minimum of approximately 15 seconds to 2 minutes or more. An on/off switch  76  which is a rocker or toggle type lights indicator lamp  75  and starts timer  70  which emits second pulses at a continuous rate as selected by dial knob  71 . The output of the timer energizes relay  72  by causing current flow for one second thereby closing (normally open) contacts  74  simulating the operation of push button  47  in FIG.  5 . 
     In an alternate embodiment shown in FIG. 7, the interior wiper feature is manually operated. To make it as convenient for the driver as possible and to maintain the features of the electrically powered version, the manual drive module  80  of FIG. 7 is used instead of motor  43  and the other electrical components. 
     By pulling handle  86  in any direction for a stroke of about  18  inches (46 cm) wiper assembly  1  moves across to the driver&#39;s side from its parked position and returns to the passenger side automatically when handle  86  is released. 
     Housing  81  contains a spring reel  82  attached to it which powers reel  83  to both rewind cable  84  and return wiper  1  from the driver side to the passenger side. Flexible semi-rigid tubing  85  places handle  86  is a position convenient to the driver. Gear  87  at the output of reel  83  drives smaller gear  88  at a speed 3.5 times that of reel  83 . Output shaft  89  is coupled in at FIG. 4 in the same location as motor  43  is shown. Thus the rest of the mechanical system remains the same. 
     The driver provides energy for both parts of the back-and-forth cycle by pulling cable  84  over a short stroke. This is accomplished by the driver winding up the spring motor while pulling wiper  1  across to his or her side simultaneously through the appropriate gear ratio which multiplies the stroke distance of wiper assembly  1 . 
     It is noted that other changes made be made to the present invention without departing from the scope of the present invention, as noted in the appended Claims.