20,137. Ewart, J. W. Sept. 18. Arc lamps.-Brake-wheel lamps, or lamps of the type having a clutch on the rim of a brake wheel, wherein gripping tension of the brake chain or band is produced by means of weights, springs, or like devices, are provided with means to effect the lifting and tripping or releasing of the brake chain or band tension by an up-and-down movement of the horizontal brake lever, both lifting and tripping taking place at one side of the brake wheel. In the arrangement shown in Fig. 1, the brake chain C is attached to the radius bar B, to the lifting lever E, preferably arranged above the brake wheel A, and to the radius bar at a point situated further from the wheel centre than is the chainlifting point. The lifting portion C and the link portion D of the brake chain may be crossed. In the arrangement shown in Fig. 3, the rigid link D has a pin-and-slot connection with the lifting lever to afford play while the carbons are being parted. The clutch F is pivoted to both the link D and the bar B, and grips the rim of the brake wheel. In a modified arrangement, a spring friction brake is attached to an extension of the link between the lifting lever and the radius bar, the link engaging a stud on the bar. The brake may be faced with rubber on the contact-surface, or the brake-wheel groove may be faced with cord or the like. In other modifications, the radius bar is pivoted co-axially with the brake-wheel spindle, and the extra brake gripping tension is applied by a separate plate or spiral spring attached to the lamp frame, or by means of a weight, or the spring friction brake is rigidly attached to the lifting lever and acts on the back of the brake wheel.