Патент USA US2105299код для вставки
Jan. 11, 1938. G. P. ROBERTS ‘ - 2,105,299 . BRAKE ‘Filed Oct. 16, 1936" _ _ ‘ N ' / 776.2 62 61 )W' P/f/PC‘Z ' , £055,417: INVENTOR. - ‘BY mama“ 9, ' ATTORNEY. ' aim in. ii, i938 2,105,299 - RlE Glyn Pierce Roberts, Eingham, England, as signor to Bendix Products Corporation‘, South nd, limit, a corporation of lnoliana Application tictober 16, 1936, Serial No. 106,025 lin Great Britain October 18, 1935 1 Claim. (Cl. 188-195) This invention relates to an improved device for limiting the load which can be applied to in a movable, member, such as a member for oper .able in a sleeve M. The sleeve t2 is in turn axial ly slidable in a housing it. The Bowden cable it is connected to the sleeve 42 by a pin it jour ating the brakes of a vehicle, and more particu larly to means for rapid adjustment of such a de vice as is described and claimed in my copending naled in the rear end of the sleeve. The rear end of a coiled compression spring lit engages a washer til abutting a shoulder on application Serial No. 78,207, filed May 1, 1936. the plunger ti) and the forward end of the spring The above mentioned application shows a de vice which permits equalized application of four - 10 wheel brakes up to a certain predetermined limit, beyond which additional applying force is trans mitted only to the front brakes. This is intended engages a sleeve or bushing '52 adjustably threaded in the forward end of the sleeve t2. An arm St or any other suitable means for rota 110 tion of the sleeve 52 is provided thereon and is preferably made accessible to the driver through an opening in the ?oor-‘board (not shown) of the vehicle, although remote operating means mounted, e. g. on the dashboard of the vehicle, M to prevent skidding of the rear wheels due to the shifting of the weight of the vehicle during de ' 15 celeration. Since the passenger or weight load of a vehicle often represents a large proportion ‘ might be employed. The plunger it is held against the pin it by of the gross weight it has been found that dif ierent limits of rear wheel braking load are de the spring t8 so that the plunger til and the sleeve sirable when a vehicle is loaded and when un~ t2 occupy ?xed relative positions as long as the spring force is not exceeded. 20 loaded. 20 An object of the invention is to provide ex . The rear end of the plunger til is formed with ternal, easily operable means for varying the ef a conical surface 56 and engaging this surface fect of a vehicle brake load limiting device. are a plurality of rolls 58 loosely held in slots til a. - Another object of the invention is to provide 25 means, readily accessible to the driver of a ve in the sleeve t2. In inoperative position these rolls are’ positioned just out of contact with the 25 7 hicle, for varying the effect of a vehicle brake housing lit. load‘ limiting device to correspond to a loaded In operation, when the brakes are ‘applied, the or unloaded condition of the vehicle. movement of the hand lever ill transmits equal Other objects and desirable particular con _ forces to the tension members-22 and .30. The 30 structions will be apparent by reference to the force in the member-3U is transmitted to the following detailed description of an illustrative plunger ill and thence through the spring, to the embodiment of my invention shown in the ac sleeve t2 and Bowden cable 341 and all these companying drawing, in which: members move together to apply the rear brakes Figure 1 is a partially diagrammatic view of equally with the front brakes. But if the brakes 35 a vehicle brake system. employing my invention; are applied very hard, the forces transmitted and will exceed the force of the spring and the plung Figure 2 is a longitudinal section through er til will move forwardly relatively to the sleeve the load limiting device employed in the sys t2, compressing the spring, forcing the rolls 58 tem of Figure 1. into contact with the housing ill and locking the The illustrated brake system may be operated plunger against further movement. , 40 by any desirable means such as a hand lever it Additional force on the hand lever ill swings having extending therefrom a tension member l2 the equalizer bar it and effects only the front engaging an equalizer bar It. The equalizer bar brakes 20. ' is, adapted to rotate a pair of coaxial cross-shafts ‘As above stated, it is desirable to vary the 45 it and i8. Shaft it operates the front brakes limit of the amount of force transmitted to the 20 through a tension member 22, a vertical shaft rear brakes when the vehicle is diiierently loaded 24 and tension members 26. The shaft l8 oper and it may be desirable also to change the limit ates the rear brakes 28 through a tension mem for diiierent road surfaces or during wet weather. ber 30, the novel load limiting device 32, a These variations are accomplished by rotating 50 Bowden cable and conduit 3t operatively engag the threaded sleeve 52 by means of the handle ing a vertical shaft 36, and tension members 38. 54 and thus increasing or decreasing the com Referring to Figure 2 illustrating in detail one pression of the spring 48. When it is desired only to vary the spring form of my invention, the tension member 30 from the cross-shaft i8 is connected to the for~ force between two limits corresponding to com 65 ward end of a plunger 40 which is axially slide pletely loaded and unloaded conditions of vthe 30 35 40 45 50 55 2,100,299 vehicle, it is desirable to provide a stop such as the tongue 02 secured to the housing 44 which, by engaging the lever 54, prevents the sleeve I! from being rotated more than approximately one revolution. By properly proportioning the pitch or the thread on the sleeve 62 the range of adjustment maybe adapted to any particular .vehicle. It may also be desirable to employ some form of spring detent capable of holding the 10 sleeve 52 and lever 54 in any one of several intermediate positions. ' While only one embodiment of my invention has been described in detail it is to be under stood that many variations of form and arrange 16 ment might be made within the scope of the inventive idea, and consequently, it is not my intention to be limited by that embodiment or otherwise than by the terms oi’ the appended claim. I claim: ‘ A load limiting device ‘for a vehicle brake com prising a plunger, a sleeve, a housing, a second sleeve adjustably threaded in the ?rst sleeve, a spring effectively interposed between the plunger and the second sleeve, wedging elements, said plunger having means operated by relative move ment between‘said plunger and said sleeves for engaging said wedging elements with said hous ing to lock the plunger thereto, said second sleeve 10 having means for shifting it to either of two positions giving different spring actions, and said housing being provided with a projection form ing a stop for said last named means permitting it to be moved between said two positions cor 15 responding to loaded and unloaded condition of the vehicle. ' GLYN PIERCE ROBERTS.