U.S. patent number 3,633,231 [Application Number 04/874,355] was granted by the patent office on 1972-01-11 for scrubbing apparatus for vehicle-washing stations.
This patent grant is currently assigned to Societa Ceccato & C. S.p.A.. Invention is credited to Uberto Capra.
United States Patent |
3,633,231 |
Capra |
January 11, 1972 |
SCRUBBING APPARATUS FOR VEHICLE-WASHING STATIONS
Abstract
One or more scrubbing brushes, rotatable about generally
vertical axes, are suspended from respective carriages displaceable
across the path of a vehicle on a portal frame movable with
reference to that vehicle. The carriages are horizontally biased
toward the center of the frame and are guided in a structure which
is limitedly swingable about a transverse axis above the vehicle so
that a traction roller on the brush shaft engages a friction
surface on the guide structure to drive the carriage outwardly,
against its biasing force, at certain stages of operation. A
deflector engageable by an idler roller on the same shaft prevents
contact between the traction roller and the friction surface at
other times, this deflector being displaceable by a servomechanism
if two oppositely movable brush carriages are provided.
Inventors: |
Capra; Uberto (Vicenza,
IT) |
Assignee: |
Societa Ceccato & C. S.p.A.
(Vicenza, IT)
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Family
ID: |
25363566 |
Appl.
No.: |
04/874,355 |
Filed: |
November 5, 1969 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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814261 |
Apr 8, 1969 |
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Foreign Application Priority Data
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Oct 15, 1969 [IT] |
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23400/A 69 |
Nov 6, 1968 [IT] |
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23382/A 68 |
Dec 10, 1968 [IT] |
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23830/A 68 |
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Current U.S.
Class: |
34/666; 15/53.2;
15/DIG.2 |
Current CPC
Class: |
B60S
3/063 (20130101); Y10S 15/02 (20130101) |
Current International
Class: |
B60S
3/06 (20060101); B60s 003/06 () |
Field of
Search: |
;15/DIG.2,21D,21E,53,97,302 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Roberts; Edward L.
Parent Case Text
This application is a continuation-in-part of my copending
application Ser. No. 814,261 filed 8 Apr. 1969 and now abandoned.
Claims
I claim:
1. An apparatus for scrubbing vehicular surfaces, comprising:
a portal frame movable relatively to a vehicle to be scrubbed, said
frame having a lintel extending transversely above such
vehicle;
guide means spanning said frame below said lintel;
at least one carriage pivotally mounted on said guide means for
reciprocation across said frame and swinging in a plane transverse
thereto;
rotatable brush means suspended from said carriage by a generally
vertical shaft rising beyond the swing axis of said carriage to the
level of said lintel;
biasing means coupled with said carriage for urging same toward the
center of said frame;
drive means on said carriage for rotating said shaft;
a traction roller mounted at the top of said shaft for rotation
therewith, said lintel being provided with a friction surface
parallel to said swing axis engageable by said roller for
entrainment of said carriage in a swung-out position thereof
against the force of said biasing means:
and blocking means on said lintel engageable with said shaft for
selectively preventing engagement of said friction surface by said
roller.
2. An apparatus as defined in claim 1 wherein said drive means is
reversible, said guide means being provided with a second friction
surface confronting the first-mentioned friction surface with said
traction roller interposed therebetween for alternate engagement
therewith, said shaft being tiltable into two opposite limiting
positions for effecting such engagement, said blocking means being
operative to prevent said shaft from reaching either of said
limiting positions.
3. An apparatus as defined in claim 2 wherein both said friction
surfaces extend over substantially the full length of said lintel,
said blocking means comprising a deflector substantially
coextensive with said friction surfaces and swingable about an axis
parallel thereto for alternate engagement with opposite sides of
said shaft.
4. An apparatus as defined in claim 3 wherein said shaft is
provided with an idler roller engageable with said deflector.
5. An apparatus as defined in claim 3 wherein said lintel is
provided with abutments alternately engageable by said deflector on
opposite sides of said shaft.
6. An apparatus as defined in claim 3, further comprising servo
means coupled with said deflector for swinging same into either of
two alternate limiting positions.
7. An apparatus as defined in claim 6 wherein said servo means
comprises a fluid-actuated piston.
8. An apparatus as defined in claim 2 wherein said guide means
comprises a structure swingable about a horizontal axis parallel to
said friction surfaces.
9. An apparatus as defined in claim 8 wherein said structure is
provided with stabilizing means tending to maintain same in a
median position in which said shaft is tiltable against the
vertical by only a small angle on either side.
10. An apparatus as defined in claim 9 wherein said stabilizing
means comprises a source of restoring force anchored to said
structure.
11. An apparatus as defined in claim 2 wherein said guide means
comprises an elongate element tiltably supporting said
carriage.
12. An apparatus as defined in claim 11 wherein said carriage is
provided with a plurality of longitudinally spaced contactors
engaging said element from above and an intermediate contactor
engageable with the underside of said element for preventing
excessive rocking of said shaft in the plane of said frame.
13. An apparatus as defined in claim 12 wherein said element is a
rod of circular profile, said contactors being balls journaled in a
sleeve surrounding said rod.
14. An apparatus as defined in claim 12 wherein said element is a
rail with an upstanding web and a bottom flange having a convex
lower surface centered on the upper edge of said web, said
longitudinally spaced contactors being grooved rollers riding said
web.
15. An apparatus as defined in claim 2, comprising a second
carriage on said guide means and second rotatable brush means
suspended therefrom with a shaft and drive means therefor
substantially duplicating the first-mentioned carriage, brush
means, shaft and drive means, said biasing means being coupled with
said carriages for urging same toward each other upon the scrubbing
of opposite sides of a vehicle, said blocking means comprising a
deflector concurrently engageable with both said shafts.
16. An apparatus as defined in claim 15 wherein both said friction
surfaces extend over substantially the full length of said lintel,
said deflector being a strip substantially coextensive with said
friction surfaces and swingable about an axis parallel thereto for
alternate engagement with opposite sides of said shafts, said strip
having a central cutout clearing both said shafts in a juxtaposed
position of said carriages.
17. An apparatus as defined in claim 16, further comprising
fluid-actuated servo means coupled with said strip for swinging
same into either of two alternate limiting positions.
Description
My present invention relates to an apparatus for the scrubbing of
vehicular surfaces, as used in a washing station for automotive
vehicles.
In such washing stations it is customary to provide a portal frame
whose uprights or jambs straddle the path of a vehicle to be washed
while its lintel extends transversely above this vehicle, the frame
of the vehicle being relatively movable in a longitudinal direction
(i.e. at right angles to the lintel) during a scrubbing operation.
For this purpose the frame jambs may be mounted on rail-supported
rollers or the vehicle may be slowly driven or towed through the
frame.
In my copending application Ser. No. 707,836 filed 23 Feb. 1968,
now U.S. Pat. No. 3,500,487, I have disclosed a frame of this
general type on which a rotary scrubbing brush is suspended from a
carriage slidably guided along a horizontal track for displacement
in one direction or the other under the control of weights
connected to the carriage via flexible cables; the weights move in
respective wells which can be alternately filled with water and
drained so that the carriage is pulled in one direction or the
other.
In a system of this type, as noted in my copending application Ser.
No. 814,261, it is frequently desirable to arrange the pull of the
weights in such a way that the carriage and its brush or brushes
will always be urged toward the center of the frame, thereby
exerting the necessary pressure upon the lateral surfaces of the
vehicle when the brush moves along these surfaces. When scrubbing
either the front or the rear end of the vehicle, the brush will be
advanced by this pull until it reaches the centerline whereupon a
supplemental force must be provided to complete the sweep against
the biasing effect of the weights. Thus, again in accordance with
the disclosure of my copending application Ser. No. 814,261, the
brush carriage is propelled across the remainder of the frame
opening by the engagement of a traction roller on the generally
vertical brush shaft with a friction surface extending across the
top of the frame.
Advantageously, in such a system, the frame carries two parallel
friction surfaces which are alternately engageable by the traction
roller, depending on whether the brush is tilted out of the plane
of the frame in one direction or the other. During the sweep of the
front end of a vehicle, for example, the tilt of the brush will be
forward so that the traction roller, if mounted at the upper end of
the shaft beyond the suspension point, will engage the more
rearwardly disposed guide surface; the opposite will be true during
the scrubbing of the rear end of the vehicle. When sweeping along
the side, the brush may swing in one direction or the other,
depending on its sense or rotation; in either case it would not be
desirable to displace the carriage from the position reached at the
end of the preceding scrubbing stage, i.e. the sweeping of the
front or rear surface. Thus, means should be provided for blocking
the engagement of the traction roller with either of these friction
surfaces during certain stages of operation.
Such blocking means, as likewise disclosed in my copending
application Ser. No. 814,261, advantageously may take the form of a
deflecting strip engageable by an idler roller on the shaft, the
strip being swingable about a horizontal axis parallel to the
friction surface so as to lie alternately on one or the other side
of the shaft.
An object of my present invention is to provide an improved
mounting for the brush carriage which, without enabling any
untimely engagement between the traction roller and an associated
friction surface, allows the brush shaft to be swung through a
greater angle of tilt than normally necessary upon encountering
salient formations on a vehicular surface to be scrubbed.
Another object of the present invention is to provide stable
low-friction guidance for the shaft-supporting carriage.
It is also an object of my invention to provide means for allowing
the use of a deflector, of the general type described and
illustrated in my copending application Ser. No. 814,261, with a
pair of symmetrically displaceable carriages designed to scrub
opposite sides of a vehicle.
According to an important feature of my invention, the deflector
and the guide track for the brush-supporting carriage are part of a
structure which extends across substantially the entire width of
the portal frame, advantageously just below its lintel, and is
oscillatable about a horizontal axis against a stabilizing force
tending to maintain it in a median position in which the brush
shaft is tiltable against the vertical by only a small angle on
either side. Thus, with the shaft swung out into one of its normal
limiting positions, an additional deflection is possible by
swinging the entire guide structure against a stabilizing force
which may be supplied by a weight, a spring or equivalent restoring
means.
In this manner, I eliminate the need for a flexible joint in the
shaft itself as described and illustrated in my copending
application Ser. No. 814,261.
According to another feature of my invention, advantageously but
not necessarily combined with the preceding one, the guide track
for the brush carriage or carriages is constituted by an elongate
element tiltably supporting each carriage, e.g. a rod of circular
profile or a rail having an upstanding web. A plurality of
longitudinally spaced contactors, such as balls or grooved rollers,
engage this element from above while an intermediate contactor is
closely spaced from the underside of that element to prevent
excessive rocking of the shaft in the plane of the frame.
According to a further feature of my invention, the brush shafts of
two oppositely biased and symmetrically movable carriages coact
with a single deflector concurrently engageable by both shafts, the
deflector being advantageously a strip or blade provided with a
central cutout which clears both shafts in a juxtaposed position of
the tow carriages whereby the deflector may be swung to one side or
the other before the carriages move apart. Such swinging of the
detector is preferably accomplished with the aid of fluid-actuated
servo means including a hydraulic or pneumatic piston coupled with
the strip for displacing it in timed relationship with the movement
of the carriages.
The above and other features of my invention will be described in
greater detail hereinafter with reference to the accompanying
drawing in which:
FIG. 1 is a front-elevational view of the upper part of an
otherwise conventional portal frame equipped with my improved
guidance and control means for a suspended scrubbing brush;
FIG. 2 is a cross-sectional view taken on the line II--II of FIG.
1;
FIG. 2A is a fragmentary view similar to the upper part of FIG. 2,
showing a modification;
FIG. 3 is a perspective view of a swingable guide structure forming
part of the assembly of FIGS. 1 and 2;
FIG. 4 is a view similar to FIG. 2, illustrating another
embodiment;
FIG. 5 is a cross-sectional view taken on the line V--V of FIG.
4;
FIG. 6 is a view similar to FIG. 4, illustrating a further
modification;
FIG. 7 is a view similar to FIG. 5 taken on the line VII--VII of
FIG. 6;
FIG. 8 is a perspective view of the top of the portal frame (parts
broken away) with two scrubbing brushes suspended and controlled in
accordance with my present improvement;
FIG. 9 is a diagrammatic view of a servosystem for controlling a
deflector forming part of the assembly of FIG. 8;
FIG. 10 is a somewhat diagrammatic cross-sectional view of part of
the assembly of FIG. 8;
FIG. 11 is a diagrammatic plan view illustrating the displacement
of the brush of FIGS. 8-10 in the scrubbing of a vehicle;
FIG. 12 is a view similar to FIG. 10, showing the parts in an
alternate operating position; and
FIG. 13 is a view similar to FIG. 11, illustrating another phase in
the scrubbing of the vehicle.
In FIGS. 1-3 I have shown part of a portal frame 1 having jambs 1a,
1b and a lintel 1c, this frame being of such size as to span the
automotive vehicle in a washing station. Just below the lintel 1c
the frame carries an assembly 2 for the guidance of a transversely
reciprocable carriage 3, this assembly including a structure 10 of
inverted-trough shape with a pair of cheek plates 10' which are
pivoted at 14 to a pair of arms 50 depending from an overhanging
portion of lintel 1c. Pivot pins 14 oscillatably support a guide
rail constituted by a pair of confronting channel members 3', 3"
embracing a group of rollers 51, 52, 53 on carriage 3; rollers 51
and 52 rest on the lower channel member 3' whereas roller 53 is
slightly spaced from the upper member 3" to engage it upon an
excessive lateral swing (in the plane of the frame 1) of a shaft 7
rotatably journaled in carriage 3. Shaft 7 is driven, via a belt or
chain transmission 6, from an electric motor 5 secured to the
carriage and energized through a flexible cable not shown; the
lower end of this shaft supports a scrubbing brush 4 of generally
cylindrical configuration. The top of shaft 7 carries a knurled
traction roller 8 rigid with the shaft and an idler roller 9 freely
rotatable thereon. A pair of inturned edges 11 and 11' of structure
10, extending over the full length of that structure, confront each
other on opposite sides of roller 8 and form friction surfaces
alternately engageable therewith when the shaft 7 and its brush 4
swing from their illustrated vertical position in one direction or
the other.
A pair of deflecting plates 12 are hingedly mounted at the zenith
of structure 10 so as to be swingable about a horizontal axis 54
into either of two limiting positions illustrated in dot-dash lines
in FIG. 2. In such a limiting position the deflecting plates 12
rest against one of two longitudinally extending abutments 13, 13'
on either side of idler roller 9; upon movement of shaft 7 to the
left or the right of its center position illustrated in FIG. 1,
with the brush 4 thrust out of the plane of frame 1 so that
traction roller 8 engages one of the two cooperating friction
surfaces 11, 11", its idler roller 9 comes to lie either forwardly
or rearwardly of a deflector 12 (as seen in the direction of
vehicle motion) so that a reverse swing of the brush will be
stopped by contact between idler roller 9 and deflector 12 before
the traction roller 8 can engage the opposite friction surface, the
deflector then coming to rest against one of the two abutments 13,
13'. With a vehicle V (FIGS. 11--13) approaching the frame 1 (or
vice versa) in the forward direction, i.e. so that its front end
comes into contact with the brush 4, this brush is deflected
forwardly whereby the shaft 7 tilts about the pivotable axis of
pins 14 in a clockwise sense as viewed in FIG. 2. Roller 8
thereupon engages the rear edge 11' of guide structure 10 so that
the carriage 3 will move along the rail 3', 3" in a direction
depending on the sense of rotation of shaft 7.
Carriage 3 is biased into its illustrated central position by a
pair of wires 55a, 55b passing around deflecting rollers 56a, 56b
on frame 1, these wires being anchored to respective weights as
diagrammatically represented by arrowheads 57a, 57b. If the brush 4
is to scrub first the left side of the vehicle, weight 57b is
rendered effective (as by immersing the weight 57a in water in the
manner disclosed in my prior U.S. Pat. No. 3,500,487) so that a
pull to the right (as viewed in FIG. 1) is exerted upon the
carriage; against this pull the carriage is displaced to the left
by a counterclockwise rotation of its traction roller 8 as viewed
from above. When the brush moves off the left-hand front end of the
vehicle, gravity tends to restore the shaft 7 to its normal
vertical position; as the brush continues its counterclockwise
rotation, however, its frictional engagement with the left vehicle
surface (against which it is urged by the rightward pull of wire
55b) tends to swing the brush rearwardly so that roller 8 is moved
toward the forward friction surface 11. Owing to the interposition
of deflector 12, however, the roller 8 is kept out of contact with
that surface and does not cause on untimely return movement of the
carriage. When, next, the brush clears the side of the vehicle, the
pull of wire 55b draws the carriage back toward the center of the
frame; this coincides with a reversal of the relative motion of
frame 1 and vehicle V so that the brush 4 is held in its rearwardly
deflected position, with roller 9 still engaging the deflector 12
so that no traction is exerted upon the carriage through roller 8.
As the carriage returns to its midposition, roller 9 reaches a
clearance between the two deflectors 12 (which could also be
combined into a single-deflecting strip, as described hereinafter
with reference to FIG. 8) so that roller 8 is now free to cooperate
with forward edge 11 in driving the carriage further to the right
against the reverse pull of the weights which now biases it in a
leftward direction. The scrubbing of the right side of the vehicle
and of the remaining half of its rear and front ends then proceeds
in a manner analogous to that described above.
The alternate tilting of shaft 7 to engage either of the friction
surfaces 11, 11', or to come to rest against an interposed
deflector 12, does not require any rocking of the guide structure
10 from its normal position illustrated in full lines in FIG. 2.
Under certain conditions, however, e.g. when the brush 4 encounters
a sharp projection on the front or rear surface of the vehicle, the
swing of the shaft must be increased. In such a situation the
entire structure 10 swings about the pivotal axis of pins 14
against a restoring force which in FIG. 2 is represented by a
weight 22 attached to a cable 20 passing around deflecting rods 21,
58 on the frame; cable 20 is anchored to the top of structure 10 so
as to stabilize its position with the aid of a further deflector
rod 16 opposing a counterclockwise swing as viewed in FIG. 2. In
lieu of or in addition to a restoring force provided by a weight
22, such a restoring force may also be supplied by a spring 18
anchored to the jamb 1a or 1b and to a cable 17' passing around a
deflecting rod 16' as shown in FIG. 2A; it will be understood that
several such weights and/or springs may be disposed along the
lintel 1c for jointly stabilizing the structure 10. Two opposite
swungout positions of that structure have been illustrated in
dot-dash lines in FIG. 2.
The brush-guiding system 102 shown in FIGS. 4 and 5 is generally
similar to that illustrated in the preceding Figures; corresponding
elements have been designated by like reference numerals preceded
by a "1" in the position of the hundreds digit. The guide element
103' for the carriage 103 has the form of a round rod traversing
the body of the carriage here shown as a solid block. Rotatably
imbedded in this block are two longitudinally spaced pairs of balls
123 serving as low-friction bearing elements in contact with the
upper rod surface. A similar ball 123' is disposed between the two
pairs of balls 123 and is closely spaced from the lower rod surface
but does not normally contact same; the presence of this additional
contactor prevents, as in the previous embodiment, any excessive
swing of the brush in response to frictional forces F, F' acting
upon the brush during the scrubbing of one of the transverse
vehicle surfaces. The number and position of contactors 123, 123'
can, of course, be modified. Rod 103, which may be fixedly held in
the cheek plates (not shown) of the guide structure 110, thus
enables a pivoting of the vertical plane of symmetry of the
carriage block between two limiting positions, relative to the
structure, as indicated by lines X-- X and U-- Y in FIG. 4. In
these positions the traction roller 108 engages either of its two
friction surfaces 111, 111' unless the idler roller 109 prevents
such engagement by its contact with the swungout deflector 112
resting against abutment 113 or 113'; as in the previous
embodiment, roller 109 never engages either of these abutments
directly. Structure 110 may again be swingably mounted, e.g. about
the axis of rod 103', on the portal frame which has not been
illustrated in FIGS. 4 and 5.
FIG. 6 and 7 show the same basic assembly 102 as FIGS. 4 and 5, yet
with a modified carriage 203 and track element 203' therefor.
Element 203' is a rail of inverted-T profile whose upstanding web
is engaged by two grooved rollers 223 journaled in the U-shaped
carriage 203. A counterroller 223' is closely spaced from the
underside of the bottom flange of rail 203', this underside being
cylindrically convex about an axis which coincides with the upper
edge of the web. Thus, the carriage 203 and the brush shaft 107 may
oscillate freely in a plane transverse to rail 203', as indicated
by an arrow C in FIG. 6, with maintenance of a substantially
constant spacing between rail 203' and roller 223'; a swing in the
plane of the frame, however, is again possible only within narrow
limits determined by the separation of roller 223' from rail
203'.
In FIG. 8 I have shown a guide structure 302 which is substantially
identical with structure 102 of FIGS. 4-7 but from which two
scrubbing brushes 304, 304' are suspended by means of respective
shafts 307, 307' carrying traction rollers 308, 308' and idle
roller 309, 309'. The two carriages rotatably supporting the shafts
307, 307' have been omitted in FIG. 8 but may have any of the
constructions illustrated in the preceding Figures. Deflector 312
is here shown as a unitary strip hinged at 302" to the top of
structure 302' (FIG. 9) and provided with a central cutout 312'
clearing the two idler roller 309, 309' in the juxtaposed position
of the two brushes 304, 304' and their respective carriages. Strip
312, which is coextensive with the friction surfaces 311, 311' and
the abutments 313, 313' on opposite sides thereof, can be swung
about its hinge axis by a servomechanism 411 shown in greater
detail in FIG. 9. This servomechanism comprises a cylinder 411 to
which air, oil or some other hydraulic or pneumatic fluid can be
admitted through a flexible conduit 417 and which can be vented via
a branch conduits. A piston 416, urged to the left by a coil spring
415, has a rod 412 articulated at 413 to the deflecting strip 312
for alternately swinging it between two extreme positions
illustrated in full and dot-dash lines in FIG. 9.
FIG. 10 shows the position of deflector 312 at the beginning of a
scrubbing cycle depicted in FIG. 11. Through proper sychronization
of the operation of valve 418 (FIG. 9) with the relative frame
motion and the action of the weights, the deflector position
illustrated in FIG. 10 coincides with a frame position A in which
the guide structure 302 lies forwardly of the vehicle V and the two
counterrotating brushes 304, 304' hang close to each other near the
centerline of the vehicle.
In FIG. 11, as well as in FIG. 13 described hereinafter, solid
arrows D, D' show the direction of the pull exerted by the weights
upon the respective brush carriages whereas hollow arrows E, E'
indicate the relative motion of the carriages and the vehicle. The
diameter of the brushes has been somewhat exaggerated in comparison
with the vehicular outline; naturally, brush carriage may support
more than one brush.
At the start, the biasing forced D, D' urge both carriages toward
the centerline and the brushes 304, 304' are swung forwardly by the
relative thrust of the vehicle and the frame; this thrust, which
could also be generated by a stored biasing force such as the pull
of weights, urges the two brushes into firm contact with the
forward surface of the vehicle V. The two brush shafts, as
illustrated in FIG. 10 for the shaft 307, now occupy the position
X-- X in which their traction rollers bear upon the friction
surface 311' whereby the two carriages move outwardly in opposite
directions as brushes 304 and 304' rotate clockwise and
counterclockwise, respectively.
It should be observed that, with the controlled displacement of
deflector 312, it is not essential that the longitudinal axis of
the vehicle V be exactly perpendicular to the plane of the frame
since the system will operate properly even if one of the brushes
is deflected before the other, thus starting earlier on its outward
travel. As each brush reaches its outermost position, having swept
a respective half a, a' of the front and of the vehicle, it
reverses its inclination as previously described so that its shaft
occupies the blocked position X'--X' shown in FIG. 10 while the
brush sweeps the corresponding lateral surface b or b'. After
passing through an intermediate position A', the frame reaches a
terminal position A" in which the brushes maintain their
inclination but move toward each other in response to their biasing
forces D and D', their traction rollers being held disengaged from
either friction surface 311, 311'.
After the brushes have scrubbed their respective halves c, c' of
the rear surface of the vehicle, the inclination of deflector 312
is reversed as shown in FIG. 12. Now, the return sweep starts as
illustrated in FIG. 13, with the frame moving successively through
positions B, B', B". In position B, again, traction is exerted upon
the brush carriages by the engagement of rollers 308, 308' with
friction surface 311 as illustrated in FIG. 12 for the shafts 308
assuming its limiting position X-- X. During the forward sweep
along surfaces B and B' the shafts assume the blocked position
Y'--Y' in which they remain during the reverse scrubbing of front
halves a, a' in frame position B".
The swing of structure 10 from its normal position (FIG. 2), or of
equivalent structures shown in other Figures, may be used to
operate a switch, not shown, for arresting the relative frame
motion to permit the removal of an obstacle (e.g. an object
extending from a window of the vehicle) encountered by the brush in
its sweep.
* * * * *