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United States Patent Office.


Charles R. Underhill, of New Haven, Connecticut.

Brake Mechanism.


1,309,377. Specification of Letters Patent. Patented July 8, 1919.

Application filed March 12, 1917. Serial No. 154,297.

To all whom it may concern:

Be it known that I, Charles R. Underhill, a citizen of the United States, and resident of New Haven, in the county of 5New Haven and State of Connecticut, have invented certain new and useful Improvements in Brake Mechanism, of which the following is a specification.

This invention relates to brake mechanism, 10and particularly to brake mechanism for a rotating element. The invention, which is particularly adapted for use in connection with motor cars or motor trucks, has for its main object to provide mechanism which is 15power operated and in which the effectiveness of the power-operated means may be considerably augmented by manually or pedal operated or controlled means.

It is a further object of the invention to 20so construct the mechanism that, should the power operated means become inoperative for any reason whatsoever, the manually or pedal operated or controlled device may be used, entirely, for setting the brakes.

25The invention contemplates, broadly, the employment of any suitable power means for operating the braking member or members, and a suitable manually or pedal operated or controlled element for rendering the 30power means operative and effective to various degrees, which means is also operative to apply the braking member or augment the effect of the power means.

The embodiment of the invention illustrated35 in the drawing, which is chosen for the sake of convenience of illustration, includes a solenoid magnet, in the energizing circuit of which a suitable rheostat is interpolated. This circuit is open when the 40braking member is inoperative, but is automatically closed upon the operation of a pedal or a manually operated or controlled element, which, itself, coöperates with the rheostat to render the magnet more or less 45effective and to positively operate the braking member or members. It is, of course, to be understood that the electric power means may be replaced by various other types of power means, and when replaced 50by such latter means, the controlling element for the power means will be suitably modified to meet the particular conditions.

Referring to the embodiment illustrated in the drawing:—

55Figure 1 is a diagrammatic view illustrating my improved brake mechanism for application to a motor car or truck; and

Fig. 2 is a detail sectional view on line 2—2 of Fig. 1.

60In the drawing, I have illustrated a conventional braking element which includes a band brake 1, of the expanding type, which is operative within a rotating member, such as a gear 2, and is operated by a suitable 65applying device 3, to which an operating rod 4 is connected. It is, of course, to be understood that this particular structure is in no way essential to the present invention, as any braking element may be used. The 70operating rod 4 is pivoted at one of its ends, that is to say, at the end remote from the brake-applying member 3, to a lever 5. This lever 5 is suitably pivoted between its ends, at 6, to any convenient support. Adjacent 75to the end remote from the rod 4 is located a solenoid magnet 7, the core 8 of which is pivoted to the adjacent end of the lever 5. Thus, it will be seen that upon the energization of the magnet, the core will be attracted 80and will be effective to move the lever 5 about its pivot in such a direction that the brake applying element 3 will be operated. The movement of the lever in the opposite direction is produced by a spring 9, or other 85suitable device, and this movement is limited by a stop 10. The magnet 7 is included in a morally open circuit 11 which includes, in addition to the source 12, a rheostat R. A controlling element 14, which, in the 90drawing, is disclosed as a pedal, but which may, as a matter of fact, be any suitable means, is pivoted at 15, and is provided with an upwardly extending arm 16 having a tread 17 thereon, and a downwardly extending 95arm 18, in the path of movement of which the lever 5 lies. A projection 19 extends from the pedal 14 and carries a contact 20, which is insulated from the projection. This contact 20 is adapted, when the 100pedal 14 is moved about its pivot by the depression of the tread 17, to engage successively a series of contacts 21 on the resistance coils 13, and is of sufficient length to bridge two or more of the contacts 21, so 105as to prevent sparking. To the pedal 14, at 22, a switch lever 23 is pivoted, which lever carries a contact 24. This contact 24 is insulated from the lever 23 and is adapted, when the lever is moved in one direction, 110to engage the contact 20, previously referred