Car towing apparatus with surge brake

Car towing apparatus having a surge brake system on a tow bar adapted to be coupled to the brakes of the towed vehicle to actuate the same upon actuation of the brakes of the towing vehicle.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to vehicle towing apparatus; and, more particularly, 
to apparatus for towing a vehicle having a surge braking system 
incorporated therein. 
2. Description of the Prior Art 
In my U.S. Pat. No. 4,761,015, I disclosed a vehicle towing apparatus which 
can be stowed under the undercarriage of a tow vehicle which can be used 
to tow a vehicle, particularly a front wheel drive vehicle, without adding 
to the mileage of the vehicle. 
However, in my patent, there is no provision for automatically braking the 
towed vehicle as a result of surges encountered during towing. There is a 
need for a tow bar having a surge braking system built-in which system is 
automatically engaged to brake the towed vehicle when the towing vehicle 
is braked. 
SUMMARY OF THE INVENTION 
It is an object of this invention to provide car towing apparatus with a 
surge brake. 
It is a further object of this invention to provide apparatus for towing a 
car having a built-in surge brake system for automatically braking the 
towed vehicle when surges are encountered. 
These and other objects are preferably accomplished by providing a tow bar 
having a surge brake system thereon adapted to be coupled to the brakes of 
the towed vehicle to actuate the same upon actuation of the brakes of the 
towing vehicle.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIG. 1 of the drawing, a tow bar or hitch 10 is shown 
having a pair of spaced arms 11, 12 integral with spaced vertical plates 
13, 14, respectively. Plates 13, 14 are for example rectangular and may be 
bolted via bolts 15, or otherwise secured, to like mating vertical plates 
16, 17, respectively. A pair of pivot loops 18, 19 are integral with and 
extend forwardly from each plate 16, 17, respectively. The pivot pins for 
18, 19 are not seen which connect spaced apertured flanges 81, 82 on 
opposite sides of legs 22, 23 with pivot loops 18, 19. 
A yoke portion 20 comprises the remainder of hitch 10 and includes a cross 
bar 21 (FIG. 1) interconnecting two legs 22, 23. Legs 22, 23 intersect at 
an elongated portion 24 (completing the Y or yoke-shaped configuration) 
having a conventional ball coupling member 25 (see FIG. 3) thereon for 
coupling hitch 10 to the ball (not shown) of a towing vehicle (also not 
shown). 
As seen in FIG. 1, an eye member 26 is provided on one of the legs, such as 
leg 23, on yoke portion 20, and an elongated chain 27 is coupled thereto. 
As seen in FIG. 2, a U-shaped spring clip 29 may be provided on the 
underside of cross bar 21. Also, spaced threaded bolts 30', 31', (FIG. 1), 
extending through washers 32', 33', respectively, are provided in each of 
arm 11, 12 for reasons to be discussed. As seen in FIG. 4, plates 13, 16 
are generally vertical and arms 11, 12 may extend away and downwardly from 
16, 13 at an angle of a few degrees with respect to the horizontal. Legs 
22, 23 are each comprised of a first portion 30 extending downwardly from 
plates 13, 16 at an angle with respect to the horizontal of a few degrees 
and an integral second portion 31 extending upwardly and outwardly away 
from portion 30 at an angle of few degrees with respect to the horizontal. 
Elongated portion 24 may be at a slight angle with respect to the 
horizontal and is generally co-planar with the angle of portion 30. 
As particularly contemplated in the invention, surge brake means 32 are 
provided on hitch 10 and comprises a housing 33 (FIG. 3) mounted on top of 
elongated portion 24. The components of the housing 33 are conventional 
surge braking components well known in the art, such as the surge brakes 
manufactured and sold by Dico Co, Inc. of Des Moines, Iowa under the model 
No. 60. Thus, other than in the environment hereafter and heretofore 
described, the actual type of surge brake per se utilized, forms no 
particular part of the invention. 
Thus, surge brake housing 33 has a control lever 34 extending out of slot 
35 in housing 33 for controlling the internal components thereof. Lever 34 
terminates in an apertured end 36 receiving therein an S-hook 37. An 
elongated wire cable control line 38 is coupled to S-hook 37 and, as seen 
in FIG. 2, terminates in a releasable S-hook 39. As seen in FIG. 5, a 
U-shaped piece 40 is also provided on top of arm 23. 
Wire cable 38 is a safety cable that attaches to the towing vehicle at the 
towing vehicle's bumper by a conventional pin mechanism. Should the ball 
of the hitch break loose, then the cable on being pulled locks the brakes 
of the towed vehicle as is known in the art, by actuating the surge brake. 
As also seen in FIG. 5, a fluid conduit 41' and an electrical conduit 42 
are coupled to housing 33 operatively coupled to housing 33's inner 
mechanism. As seen in FIG. 1, conduit 41' extends to a connector 88 where 
it is fluidly coupled to a fluid hose or conduit 41. These conduits 41, 42 
may be secured to arm 22 by spaced clips 43 and straps 44. Each conduit 
41, 42 terminates in quick release connectors 45, 46, respectively (see 
FIG. 2). 
As seen in FIG. 7, a vertical flange plate 50 is secured to plate 16 and a 
U-shaped bracket 47 with spaced holes 48, 49 therethrough is secured to 
plate 50. A second vertical flange plate 51 is secured to a horizontal 
plate 85, which is mounted on arm 11, per FIG. 1. Horizontal plate 51 has 
a connector 52 for coupling connector 45 of conduit 41 thereto. (See FIG. 
7) A like connector 53 (shown in dotted lines) normally covered by cover 
plate 54 is also provided on plate 51. As seen in FIG. 7, fluid conduit 41 
is coupled to connector 52 via connector 45. Electrical conduit 42 is 
shown as uncoupled from connector 53 via connector 46, (FIG. 6). The plate 
54 is pivotally mounted on flange plate 51. 
As seen in FIG. 1, connectors 55, 56 (similar to connectors 52, 53, 
respectively) are provided on the other side of plate 51 for receiving 
conduit 57, 58, respectively. Thus plate 51 serves as an intermediate 
connection point for electrical and hydraulic conduits from the towing and 
towed cars. Conduit 57 thus provides a continuation of conduit 41, when 
coupled to connector 52, and conduit 58 provides a continuation of cable 
42 when coupled to connector 53. Conduit 58 terminates in a quick release 
coupler 90. See also FIGS. 7 and 8. 
Reference is now made to FIG. 8. Leading to connector 45, but undesignated 
in this FIG is conduit 41. Connector 45 is fluidly connected to connecter 
55 of conduit 57 at plate 51. This fluid conduit terminates at connector 
66 at the input end of actuator 67. See also FIG. 9, but note that the 
position of actuator 67 has been reversed 180 degrees. 
Turning now to FIG. 9 and FIG. 11 one sees actuator 67 is a generally 
hexagonally shaped elongated housing 68 designated in FIG. 9 and having an 
apertured bracket 69 secured thereto, the apertures being designated 80 
and being located in the two flanges 69'. The bracket 69 rests in an 
optional recess 71 of housing 68. A pair of spaced fluid inlets 70, 73 are 
provided on housing 68. A bleeder valve 72 is secured to housing 68 on one 
surface. Fluid outlet 70 communicates via line 94 to the master cylinder 
91. See also FIG. 8. This connection 70 is centrally located in threaded 
closure 79 that closes off opening 83 of housing 68. 
The connection that also communicates via a fluid conduit 41' and connector 
52 to the surge brake is connection 73 in housing 68. Thus, fluid 
connection 74 on the surface of the housing 68 fluidly communicates via 
conduit 95 tee 59 and conduits 96, 97 to the front wheel cylinders, 92 and 
93 as seen in FIGS. 8 and 12. 
Reference should now be made to FIG. 10, which illustrates the mode of 
operation of the automatic actuator 67 in the normal operating condition, 
in which the towed vehicle is under operator control. Upon stepping on the 
brakes, brake fluid F is pumped through connector 73 into chamber interior 
76. See FIG. 10-II. The fluid F impacts piston 77 and moves it to the 
opposite end of the chamber (see FIG. 10-III). The fluid then exits out 
connector 74 to actuate the front wheel brakes. 
When vehicle TD is not under operator control, but is being towed, 
obviously no person can actuate the car TD's brakes. During this time 
period, when the brakes of the TG towing vehicle are applied, fluid is 
delivered via input connector 70 into chamber 76 from the surge brake 32 
in response to brake pedal actuation in the TG or towing vehicle. In such 
instance, piston 77 moves in the direction opposite that shown in FIGS. 
10-I, 10-II and 10-III. 
Conventional o-rings 78 strategically placed maintain the seal of fluid for 
at least the two inlet and one outlet connections of actuator 67. 
MOUNTING AND OPERATION 
In the discussion above and below herein the towed vehicle will be 
designated by the letters TD rather than numerically and the towing 
vehicle will be designated TG. Reference is made to FIG. 11 where a car 
body (TD) is shown in dashed line and the frame is excluded for ease of 
understanding. This depicts the mounting of the invention to the 
undercarriage. The discussion to follow describes both the mounting of the 
components, the operation during towing, and their operation during 
non-tow periods. 
For setup, the ball coupler 25 is coupled to the ball (not shown) of the 
towing vehicle, TG. Hook 39 is coupled to the opposite end of cable 38 - 
FIGS. 3 and 5, for connection to the bumper of vehicle 76 by a pin. Arms 
11, 12 extend under the frame of the vehicle being towed and conventional 
apertured U-shaped clips 89 (only one shown in exploded view in FIG. 1) 
are placed over a frame member, and secured via bolts 30', 31' to arms 11, 
12. Other conventional attachment modes to the car frame are also 
contemplated. Quick release coupler 90 (FIG. 1) of conduit 58 is coupled 
to a mating coupler (not shown) coupled to the brake lights of the towed 
vehicle for conventional towing brake light operation. Conduit 57 is in 
turn coupled to actuator 67 (FIG. 8) which is bolted to the frame, not 
shown, and which actuator is in turn coupled to the master cylinder 91 
(FIG. 11) of the vehicle being towed. The master wheel cylinder 91 is in 
turn coupled to the wheel cylinders 92, 93 of the two front wheels of the 
vehicle being towed via conduits 94 to 97 as seen schematically in FIGS. 
12 and 13. 
When vehicle TD is being towed, the actuator is in position II, when surge 
brake 32 is actuated upon braking of the towing vehicle, as seen in FIG. 
13, hydraulic fluid from surge brake 32 enters conduit 41 and into 
actuator 67 where it passes via conduits 95 to 97 into wheel cylinders 92, 
93 as indicated by the arrows. Thus, the towing vehicle applies the 
brakes, and the brakes of the vehicle being towed are actuated, as a 
result thereof. 
FIG. 12 illustrates driving or non-towed operation of actuator 67. As seen 
in FIG. 12, brake fluid from the master cylinder 91 of the vehicle TD 
enters actuator 67 via conduit 94 and exits actuator 67 via conduit 95 
where it passes to conduits 96 and 97 leading to wheel cylinders 92, 93, 
respectively. These are the normal driving conditions when not towing the 
vehicle. The arrows show the flow path of the brake fluid. 
The conduits 96, 97 can of course be coupled to the rear wheel cylinders of 
the towed vehicle. 
It can be seen that there is provided a tow bar having braking means for 
actuating the brakes of the towed vehicle. Thus, control over the stopping 
or braking ability of the towed vehicle is provided. When the towing 
vehicle, TG, brakes, the forward motion of the towing vehicle stops and 
actuates the surge brake means 32 which in turn actuates the brakes of the 
towed vehicle at substantially the same time. 
When the towed vehicle TD, is not being towed, i.e. its brakes are 
operating under the control of the driver of the towed vehicle, actuator 
67 is left in place, bolted to the undercarriage on frame of the TD 
vehicle. In order to place actuator 67 in condition for receiving brake 
fluid from the surge brake for FIG. 13 operation, one must do nothing, 
since the switch from operator control to surge brake control is 
automatic, as has been explained elsewhere herein. 
Also, when the vehicle TD is not being towed arms 11, 12 remain attached to 
the frame, detachment is made of plates 13, 14 from plates 16, 17 by 
removal of bolts 15. See FIG. 4 thus the hitch 10 can be stored away 
during periods of non-use. 
Since certain changes may be made in the above apparatus without departing 
from the scope of the invention herein involved, it is intended that all 
matter contained in the above description and shown in the accompanying 
drawings shall be interpreted as illustrative and not in a limiting sense.