Semi-trailer trucks almost universally utilize pneumatic air brake systems. Such air brake systems typically require air lines or hoses on both the tractor and trailer units. These air lines are coupled together in order create a pressurized system that enables the operator to actuate the brakes of the trailer together with those on the tractor unit. Ordinarily, these air hoses are coupled together by so called “glad hand” connectors. Glad hands are coupling devices used to connect the service and emergency air lines from the truck or tractor to the trailer. The couplers have a rubber seal which prevents air from escaping. To connect the glad hands, the two seals are pressed together with the couplers at a 90° angle to each other. A turn of the glad hand attached to the hose will join and lock the couplers. A glad hand connector typically features two substantially identical glad hands. Generally, one glad hand is rigidly connected to the frame of the trailer and the other is connected to an air hose extending from the tractor's pneumatic brake system.
Glad hands typically comprise a disk shaped housing having a curved edge, an engaging tab extending from one side of the housing and a support member extending from the other end of the housing opposite the engaging tab. Generally, the support member features a retaining tab extending adjacent the housing. To mate two glad hands together, the housings are placed together, and one or both of the units are rotated until the engaging tab of each glad hand slides between the housing and the retaining tab of the other glad hand. In this position, the glad hands are securely and engagingly held together.
When the two glad hands are connected, a leak-free path exists between the air hoses of the tractor and trailer, so that high air pressure (typically 90 to 120 pounds per square inch) is maintained within the lines of both the tractor and trailer units. The brake system of the trailer is designed so that the trailer's brakes are in the fully applied state when there is no air pressure in the trailer brake lines (that is, the brakes are partially or fully engaged by partial or full release of such air pressure in the brake system). Consequently, a trailer cannot be operatively moved until the glad hand of the trailer is coupled with the glad hand of a tractor. In addition, if the glad hands are pulled apart from one another, as may happen when the tractor and trailer are separated without first uncoupling the air lines, the glad hands are designed to separate from one another without damaging the air hoses of the tractor or trailer.
In ordinary operation, such as for maintenance, it occasionally becomes necessary to remove a glad hand from the chassis of the trailer bulkhead. Previous methods for removing glad hands from the chassis of the trailer bulkhead involve using common wrenches such as a Crescent® or adjustable spanner wrench or a pipe wrench. Previous glad hand removal methods have been found to have several disadvantages. For example, glad hands are often damaged during removal as a consequence of using previous removal methods. Glad hands are designed to efficiently mate with each other, but they are not designed to handle the twisting force exerted by a Crescent® wrench or a pipe wrench used during removal. The glad hand, being typically made of cast aluminum or other like metal, is prone to cracking under the torque force of a Crescent® wrench or a pipe wrench. As explained in more detail below, the configuration of the trailer bulkhead in which the glad hand is installed, often limits the angle from which a Crescent® wrench or a pipe wrench can access the glad hand. The torque force applied by such wrenches, combined with a non-ideal torque angle can result in too much strain, and ultimately can cause stress fractures and cracks in the glad hand.
It is common in normal operation for glad hands to be affixed to the chassis of the trailer in a recessed portion of the trailer bulkhead. The recessed portion of the trailer bulkhead allows access to the glad hand by the glad hand coupler which is connected to the air hose of the trailer air brake system. The glad hand on the chassis may be accessed by the air hose of the trailer brake system. However, the recessed portion of the trailer bulkhead often restricts access to the glad hand mounted on the chassis. Specifically, the use of common wrenches is disadvantageous due to the limited space of the recessed portion of the trailer bulkhead in which the glad hand is located. The limited space restricts range of motion required by common wrenches, and also makes it difficult, if not impossible, to generate the torque required to disengage the glad hand from the trailer bulkhead.
There is therefore a continuing need for a cost effective device that can provide an improved means for engaging and rotating a glad hand while reducing the risk of damage. There is additionally a need for a glad hand removal tool that can be utilized to engage and rotate a glad hand within restricted or confined area such as trailer bulkhead.
USPTO Backgrounds
USPTO Backgrounds