Gear mechanism for brake adjustment

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT An adjustable brake operating mechanism constructed in accordance with the present invention includes a lever arm 10 of tapered construction, wider at the bottom than at the top, and near the top having a series of three spaced holes 12, 14 and 16, each of which is lined with a bearing sleeve 18.
A pneumatic or air cylinder 20 is provided with a connecting rod 22 having a clevis 24 at the opposite end from the air cylinder carrying a transverse pin 26 received in one of the bearing sleeves 18.
In the illustrated embodiment the pin 26 is received in the bearing sleeve of the central hole 14.
It will be appreciated that the different holes are provided to provide a different turning or radius length for the arm 10.
As noted heretofore, the arm is wider near the bottom, having a maximum width at 28 and tapering inwardly therefrom at 30 to a bottom corner 32 on each side, and diagonally upwardly and inwardly at 34 to a somewhat greater than semicircular recess 36 housing a worm wheel 38.
The worm gear 38 has a central aperture 40 provided with axial splines 42 for splining of a shaft thereto which actually operates the trailer brakes.
The worm gear 38, as best seen in FIG.
2, is a split gear having two axially confronting, similar halves 38a and 38b.
The halves are preferably made by a powdered metal technology involving sintering and is provided with worm teeth 44.
The two halves of the worm gear have a rubber O-ring 46 clamped in confronting annular recesses as a grease seal to prevent grease from travelling radially inwardly through the gear and out of the area where it should be.
At the bottom of the arm 10 there is provided a U-shaped saddle 48, which like the arm is made of a suitable grade of steel.
The saddle has upstanding side portions 50 and 52 lying on opposite sides of the arm 10, and spaced therefrom by suitable spacers 54, since the saddle must span the worm gear 38, which is axially of greater dimension than is the arm 10.
A pair of pins 56 and 58 join the worm saddle 48 to the arm 10