US2111734A - Hydraulic abutment - Google Patents

Description

March 22, 1938. l p R|LEY 4 i 2,111,734

f HYDRAULIC ABUTMENT y I 16 Flled Jan. 14, 1937 I7 loer@ zy Patented Mar. 22, 1938 Percy Riley, Coventry, England Application January 14, 1937, Serial No. 120,638

, In Great Britain January 17, 1936 Claims.

rIhis invention relates to adjustable abutments such 'as are hydraulically controlled, the main object being to provide an improved arrangement which is very satisfactory for use, for example, in taking up the clearancesin connection with the. Valve gear of anvinternal-combusticn engine. l'

The invention comprises the combination with a hydraulic abutment, for a slidable cam bar or other movable member, of means for applying a relatively light hydraulic pressure to the movable element of the abutment, and a valve, controlled by the movement of the said movable member, for sealing the abutment to render it solid when the said movable member is in a predetermined position. v

The single figure of the accompanying diagrammatic drawing is a sectional elevation o1"V part of an internal-combustion engine having valve mechanism embodying an abutment arranged according to the invention. The section is through the axes of the two abutments shown, the section passing tof one side of the cylinder axis and the poppet Valves for the cylinder head.

In the construction illustrated, as applied to hydraulic abutment for a slidable cam bar I2, the abutment serving for holding the cam bar against the roller I3 of a rocker I4 for apoppet valve I5, the abutment comprises a stationaryV cylinder I6 disposed at right-angles to, and adjacent, the rear face of the cam bar I2 and a piston II slidably mounted therein and adapted for anti-frictional engagement with the rear face of the cam bar. The remote end I8 of the cylinder contains hydraulic liquid Which is supplied thereto through a slide valve I9 at a relatively lightpressure at those times when the cam bar I2 is not loaded.

A simple arrangement for eiiecting this is to supply the hydraulic liquid to the inlet 20 of the cylinder I6 at any convenient pressure and to provide an outlet 2| controlled by an adjustable valve 22 so that the net pressure applied to the abutment is as desired. Alternatively, instead of using an additional valve 22, the slide Valve I9 may be adapted, as shown at 22a, to provide a small leak at the outlet.

When the gear is associated with an internal combustion engine, as is illustrated, it is convenient to make use of the pressure of the engine lubrication system for this purpose. The drawing shows the main lubrication pump 23 connected to supply lubricant under pressure to the inlet 20, the return pipe 24 leading the lubricant back to the crankcase.

(Cl. 12S-90) The slide valve I9 is associated, as by a rocking lever 25 and link 26, with the cam bar I2 in such manner that when the latter is slid the slide valve will be closed to seal the cylinder I6, with the hydraulic liquid therein, just before the inclined surface or other profiled portion 2l of the cam bar operatively engages the roller of the associated rocker I4. This renders the abutment substantially solid and the cam bar is thus maintained relatively to the rocker in the position to which it has been adjusted, when not under load, by the light pressure applied to the abutment. Conversely, on the return movement of the cam bar the slide valve I9 again opens allowing the applicationof the fluid pressure to the abutment.

The drawing shows a pair of poppet valves I5 with a common spring means 28 for closing them and individual actuating means therefor. In the left-hand mechanism, where the poppet valve i5 is shown closed, the hydraulic pressure is being applied to the associated cylinder I6. In the right-hand mechanism, where the poppet valve I5 is shown open, the slide valve I9 is shown as closing the inlet and outlet of the-associated cylinder I6.

Whilst the invention has been particularly described in connection with an hydraulic abutment for a sliding cam bar it will be evident that it is not limited in this respect.

What I claim as my invention and desire to secure by Letters Patent of the United States iszl. In combination, a slidable member having a prole portion on one face, a movable member engaged with said proiile portion, a hydraulic abutment engaged with the opposite face of Said slidable member, said abutment comprising relatively movable co-acting piston and cylinder elements, means for applying a hydraulic pressure to expand said co-acting elements, a slide valve for sealing the abutment, and means including a lever positively interconnecting said valve and said slidable member whereby Said abutment will be sealed to be rendered substantially solid when said slidable member is in a predetermined position.

2. In combination, a slidable member having a prole portion on one face, a rocker engaged with said proile portion, a hydraulic abutment including a piston slidably engaged with the opposite face of said slidable member and movable in a stationary co-acting cylinder, said cylinder having an inlet and an outlet, a valve jointly controlling said inlet and outlet, means interconnecting said valve and said slidable member whereby said valve will be moved to seal said inlet and outlet when said slidable member is moved to a predetermined position, and means for supplying hydraulic pressure through said inlet when said valve is in the open position.

3. In combination, a slidable member having a prole portion on one face, a rocker engaged with said prole portion, a hydraulic abutment engaged with theV opposite face of said slidable member, said abutment comprising a piston coacting with a stationary cylinder, said cylinder having an inlet, means for supplying hydraulic pressure to the inlet of said cylinder, a valve for sealing said inlet, and means interconnecting said valve and said slidable member whereby said inlet is sealed to render said abutment substantially solid when said slidable member is in a predeterminded position.

4. In combination, a movable member having a prole portion on one face, an actuating member engaged with said profile portion, a piston engaged with the opposite face of said movable member, a cylinder for said piston, means for supplying hydraulic pressure behind said piston to move the same toward said member, valve means for controlling` the inletk and outlet of the hydraulic pressure to and from said cylinder and for entirely cutting off the admittance and escape of pressure to and, from said cylinder, and connections between said movable member and said valve means for actuating the valve on movement of the movable member in a sequence to close the valve means when the high point of the movable member engages the actuating member and to open the valve means When the low point of the movable member is engaged by said actuating member.

5. In combination, a movable member having a prole portion on one face, an actuating member engaged with said profile portion, a piston engaged With the opposite face of said movable member, a cylinder for said piston, inlet and outlet connections for said cylinder, means for circulating fluid to the inlet connection, control means for controlling the volume of fluid admitted to said cylinder, a common valve means movably mounted across the inlet and outlet connections and having valve ports for said inlet and outlet connections, said outlet port of the valve being smaller than the inlet port, and connections between said movable member and valve for requiring the valve to move with the movable member in sequence to open Said connections when the actuating member is on the low point of the movable member and to close the valve when the actuating member is on the high point of themovable member.

PERCY RILEY.

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