US2890474A - Hydraulic door check - Google Patents

Description

June 16, 1959 y P. RFERGUSON 2,890,474 HYDRAULIC DooR cHEcK Filed Nov. 18, 1954 2 Sheets-Sheet 1 O v o Z4 l. l I' l' 1 /20 f INVENTOR PAUL R FERGUSON i ATTORNEYS P. R. FERGUSON HYDRAULIC nooR CHECK June 16, 1959 l Filed NOV. 18, 1954 I0 32. fo, 4a f I l l l l l N )T i Il l/ Y 2 60 l 56 4 54 4a 52 f6 68 Q@ /35 64 ,LM A n m" n -70 l G O f e4 f A l 44 Y y F/G. 5 l

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ATTORNEYS Unite States Patent vO" ice HYDRAULIC DooR CHECK iaul R. Ferguson, llainville, lConn., 'assignor to The Stanley Works, New Britain, Conn., a corporation vof 'Connecticut Application November 18, 1954, Serial No. `469,584

26) Claims. (Cl. 1655) This invention relates to door checks, and more particularly to an improved hydraulic checking mechanism for door checks.

One object of the invention is to provide 'a door check having an improved hydraulic checking arrangement which effectively checks both the opening and closing movement of the door.

Another object is to provide an improved hydraulic door check in which checking of door opening movement varies with the door position and speed of door movement, and the amount `of checking duringvarious stages of door opening and closing movement can be controlled and adjusted independently.

Another object is to provide a door .check in which checking of the iinal phase of door closing `movement can be controlled and adjusted independently from checking during the remainder of door movement.

Another object is to provide a hydraulic door check which is compact in size, rugged in construction, and capable of operating effectively for long periods without repah or attention.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in [the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

VIn the drawings:

Figure 1 is a plan view of a door check 'constructed 'in accordance with the present invention, with the cover removed and partly sectionalized 'to show the inner yarrangement of a Aportion of the hydraulic control mechanisrn thereof;

Figure 2 is a longitudinal sectional view of the structure of Figure l taken on the line 2-2 of Figure 3;

Figure 3 is a vlongitudinal sectional view of a `portion of the structure of Figure l taken on 'the line 3 3 of Figure 1;

Figure 4 is a horizontal longitudinal 'sectional kview of an alternative embodiment ofthe door check,partially broken away;

Figure 5 is a view of the embodiment of Figure 4 taken in the same plane as Figure 2, and showing the relation ofthe parts in an open position o'f the door; and

Figure 6 is a fragmentary schematic view of the hydraulic control system embodied inthe door check. v

Referring 'to the drawings, a door check constructed in accordance with the present invention includes va Agenerally elongate casing 2 in which all of the ioperating mechanism of the door check is contained.Y The casing is closed by a supporting cover 4 yfrom which it depends, and is filled with oil which lubricates the mechanism and serves as hydraulic uid. The cover 4 slightly overhangs the casing and also serves as the closure for arprotective housing or box 6 in which'the cover is received `and supported by a ledge 8. The housing 6 is adapted to be re- Journaled in an opening in the `cover 4 is a vertical spindle 1li-.which .is connected tothe door for rotation therewith and serves as la pivot for one end of lthe door. Fixed to the spindle 10`is a cam 12 having a main vlobe 14 and lsyn'unetri'ca'lly 'arranged spaced side lobes 16, 18. The cam risoriented 'on 'the spindle so that in the rest position of the cam when the door is closed the main lobe 14 'is 'aligned longitudinally with the casing 2. 4On its.'upper side the cam 'carries a pair' of push rollers 20, '22. symmetrically spaced relative to the main lobe I4, and on 'the lower side of the cam is mounted a pair 'of limit rollers 24, 26 likewise symmetrically spaced.

A laminated slidef30 opposite the cam is mounted for 'recprocation in a channebshaped 'track 32 Vsupported from the 'cver 4 .and longitudinally aligned with the cas'- ing.` The slide *30 has la projecting shelf 34 which 'is engaged by the push'rollers 20, 22 to displace the slide 'to the right as shown in 'Figure '1 'when the camis 'rotated in either direction from its rest position. The. slide lis notched as 'at l3:5 'to 'freelyaccommodate the end of lobe 14 as cam 12 rotates. Aridge 36 is provided on the front face yof 'the lshelf inthe path of the push rollers 20, 22 to sustain the rate of displacement of Athe slide 30 as the cam 12 'approaches ninety .degrees rotation from its rest position. Below 'the cam the slide carries a stop member 38, .the ends of which Vstraddle the spindle 10 and are engaged yby the limit rollers 24, 26 to limit rotation of "the cam in either direction.

The shelf 34isurged against rollers 20, 22 by compression springsf40, 42 acting between the slide and `a spring .retainer 44. The spring retainer has an adjustably E threaded Vconnection 'with 'a worrnwheei 46 journaled in one endiof va cylinder L'block 48 depending from the cover 2t at the opposite end ofthe casing from `the cam. To permitgconvenientadjustment of (the spring force, a Worm 50 journaled in 'the `cylinder block 48 meshes with the worm wheel 46 and has a sl'otted'portion accessible at the surface of cover 4 for rotation by a screw driver.

IThe arrangement for'returning the door to closed rvposition including the rollers 20, 22, ythe slide 30 and the springs 4042 has been included only as illustrative of many specific arrangements for biasing the door to closed positions which may be used `in accordance with the 'invention. .It will be apparent to one skilled in the art that other .forms of 'closure means such as the wellknown forms of torsion spring closures'm'ay be substituted, if desired, without departing from the scope of the invention'. The details of the construction of the shaft 10 'and slide 30 as well as the details of certain unnumbered parts disclosed 'in Fig. 1 which provide latching of the slide in a door-open .position may be had by reference to my Patent No. 2,786,226, issued March 26, 1957, on my cofpending application Serial No. 466,511 led November 3, '1954.

The , springs 40, 42 are laterally stabilized by a longitudinally disposed Yspring guide tube 52 secured at one end .inja central opening inthe slide and slidably mounted at the other end "in a bore 'in the spring retainer 44. Slid- .ably mounted in the vguide tube 52 is a cam follower 54 having atone end a roller v56 which engages the cam 112. Secured to the other end of the rcam follower `54 is ya 'hollow piston rod -X58 which Vcarries at its remote end a piston `60 slidablje in 'a cylinder 62 in the cylinder block 48. The rremote end of cylinder 62 is closed by a wall 64 'which supports one end of a hollow tubular spring support 66 vslidablvinounted in piston rod 58. A comi pression .spring 68 `acting between the cam follower and cess'ed -in a door frame, 'for'examp1e, beneath the door.

an `inturned ange on the spring support 66 urges the cam follower 541again`st cam A12 and keeps the spring support seated against the cylinder end wall 64. Disposed in an opening in end wall 64 concentric with the springlsupport-i's I-a ball che'ckvalve 170 'which is-arranged 3 to admit oil freely from the casing 2 into the spring support, but prevents oil ow in the reverse direction. A notch 72 in the end of the spring support adjacent cylinder end wall 64 permits free flow of oil from the spring support into the cylinder 62.

Referring particularly to Figures 1, 3 and 6, a port 80 in the cylinder block 48 communicates with cylinder 62 at a position between the face of the piston at its point of extreme penetration in the cylinder and the end wall 64. A second port 82 communicates with the cylinder at a point longitudinally spaced from the first port intermediate the ends of the piston stroke. Port 80 connects through an orifice adjustable by a metering needle valve 84 to an oil flow passage 86 in the cylinder block which opens into the casing through a discharge port 88. The port 82 is likewise connected through an orice adjustable by a metering needle valve 90 to the passage 86. A11 adoil into the cylinder through the check valve 70, spring support 66 and notch 72. As the cam 12 is further rotated during opening movement of the door, the cam follower reaches its extreme forward displacement as the roller 56 arrives at the bottom of the main lobe 14. Further rotation of cam 12 engages one of the side lobes 16, 18 with roller 56 and displaces the cam follower in a reverse-or rearward direction, thereby causing the piston 60 to exert pressure on the oil in the cylinder. As ball valve 70 closes, oil is allowed to escape from the cylinder through ports 80 and 82 into passage 86, and

then discharges into the casing through port 88.

justing screw 92 conveniently disposed in the cover 4 constrict the ow area of the port gradually as the valve is inserted therein. A contact pin 110 is carried by the slide 30 opposite the adjacent end of the valve stem 102 and engages the valve stem to displace the valve into discharge port 88 during displacement of the slide. The end of the valve stem is substantially spaced from pin 110 when the cam is in its rest position so that the valve 100 is not operated by the slide 30 until close to the end of the displacement of the slide by cam 12. The pin 110 is threaded to permit convenient adjustment of its length in order to vary the timing and stroke length of the valve 100. The valve is normally displaced from port 88. While various biasing means such as a spring may be used to bias the valve 100 away from the port 88, in the specific embodiment the displacement of the valve is accomplished by oil pressure in the passage 86.

To permit discharge of oil from passage 86 into the casing even when the port is closed, an auxiliary passage 112 by-passing valve 100 opens at one end into the casing and connects to passage 86 through an orifice controlled by a needle valve 120. The needle valve in turn is conveniently adjustable by a screw 122 in the cover which also engages the diaphragm 94.

In operation of the door check, when the door is closed, the parts are in the position shown in Figure 2 of the drawings. The shelf 34 of slide 30 is engaged with the push rollers 20, 22, and the roller 56 of cam follower 54 is engaged with the apex of the main lobe 14 of cam 12 so that spring 68 is compressed and the piston 60 is supported at its position of furthest penetration into the cylinder. When'the door is opened, rotation of the cam from its rest position causes one or the other of the push rollers 20, 22 to displace the slide 30 rearwardly or to the right as shown in Figure 2, and allows spring 68 to drive the cam follower forwardly as roller 56 rolls down the side of the main lobe 14. The specific embodiment of the door check of the present invention shown in the drawings is one designed for use with a doorl which can be opened in either direction, or with a door which can be opened in both directions, such as a swinging door. Accordingly the cam 12 has been shown as one symmetrical in form to provide the same operation regardless of the direction in which the door is opened. In the event that the door check is to be used with a door which opens only in one direction, then, of course, only half of the cam is necessary.

The forward displacement of the cam follower retracts the piston in the cylinder and draws a charge of The rearward displacement of slide 30 during door opening however engages contact pin 110 with the end of valve stem 102 and inserts the valve 100 into discharge port 88 at a point in the door opening cycle determined by -adjustment of the length of pin 110. This causes discharge of oil from port 88 into the casing to be rst progressively restricted by the tapered orice 106 and then blocked altogether. This smoothly transfers oil discharged out of cylinder 62 from port 88 to auxiliary passage 112, the flow capacity of which may be adjusted by needle valve 120 and screw 122 to any desired rate so as to provide the desired retardation of piston 60 and hence cushion the final phase of door opening movement to any desired degree.

When the door is released for closing, the springs 40, 42, compressed by rearward displacement of slide 30 during opening of the door, return the slide in a forward direction. The slide in turn forces the cam l2 back toward its rest position. This rotation of the cam irst permits cam follower 54 to be driven forward by spring 68, enabling the piston to draw another charge of oil into the cylinder through check valve 70 and notch 72, and then reversely displaces the cam follower 54 in a rearward direction as the roller 56 is forced to ride up the side of main lobe 14 to its apex. As this happens, the piston 60 again compresses the oil in the cylinder and forces oil out through ports and 82. Since the forward movement of the slide 30 meanwhile has disengaged the contact pin from the valve stem, oil pressure in passage 86 blows the valve 100 out of the port 88 and permits discharge of oil into the casing. Oil thus flows through ports 80 and 82 at a rate determined by adjustment of needle valves 84 and 90, thus retarding movement of piston 60 and checking closing movement of the door to any desired degree. As the door approaches its fully closed position, the piston is extended to the point where it covers port 82 yand thus the door closing speed during the final phase of door closing movement may be controlled exclusively by the adjustment of needle valve 84. With any given adjustment of valve 84, of course, door closing speed during the earlier portion of the closing cycle may be adjusted independently by means of needle valve 90. Thus the initial and nal phases of door closing movement may be adjusted separately to provide any desired door closing movement.

In Figure 4 is shown an alternative embodiment differing from that of Figures l and 2 in that, during opening of the-door, the piston 60 is driven on its compression stroke directly by spring guide tube 52 rather than by the engagement of follower 54 with a side lobe on the cam. In this embodiment, the spindle 10 has wings mounting push rollers 130, 132 which displace slide 30 rearwardly or to the right in Figure 4 when the door is opened, in the same manner as push rollers 20, 22 in the embodiment of Figure 1. The cam 134 is similar in'all respects to cam 12 except that it has no side lobes. The ports and passages in the cylinder block 48 shown in Fig. 3 and described above in connection with the embodiment represented by Figures l and 2 are also provided in the alternative embodiment of Figs. 4 and 5, although not shown, and serve the same function as herein described.

In the operation of the embodiment of Figure 4,

v'rotation of spindle .10 when `the door is opened causes rol- ler 130 or 132 to displace slide 30 and turn cam k134- so that spring 68 can move follower 54 and piston '60 forwardly and charge the cylinder 62 with oil. Displacement of slide 30 likewise displaces spring tube 52 toward the piston, and the length of tube 52 is arranged so that, atthe point in the door opening cycle when it is desired vthat reverse movement of the piston begin, the end of tube 52 engages a shoulder 135 on the piston. Continued opening movement ofthe door results in engagement of the rollers 136, 33 on the cam 134i, with the slide 3i) and thus further displaces slide 30 and tube 52 and drives the piston into the cylinder on its compression stroke, hydraulically checking the door opening movement in the manner previously described. This displacement of the piston by tube 52 temporarily withdraws the vcam follower roller 56 from contact with cam 134 as shown in Figure 5.

When the door is released for closing, the springs 40, 42l return slide 30 and tube 52 to the left as shown in `Figure 4. This movement permits spring 68 to re-engage `cam follower 54 with cam 134 and displace the piston in the rcylinder so as to draw a fresh charge of oil therein. As the door continues to close, the main lobe of cam 134 reversely displaces the cam follower 54 and piston 160, and the piston again compresses the oil in the cylinder to produce the closing checking action previously described.

Thus there has been show-n and described an improved `door check which provides effective hydraulic checking of both opening and closing door movement. The door check can be adjusted to vary the degree of checking of door movement at various stages of the opening and closing movement, and permits independent adjustment of the checking action of the final phase of door lopening movement. The door check is compact in size, conveniently adjustable to give door operation with any selected characteristics, rugged in construction, and capable of operating effectively for long periods without repair or attention.

As many changes could be made in the above construction and many apparently widely different embodiments 4'of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanyiug drawings shall be interpreted as illustrative and notin a limiting sense.

It is also to be understood that the language used in `the following claims is intended to cover all of the generic and specic features of the invention herein dekscribed and all statements of the scope of the invention which, as a matter' of language, might be said to fall therebetween.

I claim:

l. In a door check, a hydraulic cyiinder, a reciprocable piston in the cylinder, a cam rotated by door movement and having spaced lobes separated by a valley, a Vcam follower engageable with the piston and engaging said cam lobes successively during movement of the door and thereby displacing the piston to effect movelment of the piston first in one direction and then in the other direction during either opening movement or during closing movement of the door, a one-way valve for admitting hydraulic uid into the cylinder during piston *movement in said one direction, a fluid escape passage connected to said cylinder for discharge of hydraulic fluid therefrom during movement of said piston in said other direction, and an adjustable flow metering valve Yin said escape passage.

2. In a door check, a hydraulic cylinder, a piston mounted in the cylinder for reciprocal movement, means for reciprocating the piston in response to movement of a ldoor in both directions from a closed position and during door movement in both an opening and a closing direction including a rotatable cam adapted to be attached to the door and a cam follower engageable with the cam and piston to control movement'of .the `piston and a spring biasing the piston toward the cam, means for admitting hydraulic iluid behind the piston during movement of the piston away from original position, and a plurality of fluid escape passages connected to the'cylinder, one of said escape passages being covered by the piston during return movement of the piston to original position.

3. In a door check, a .hydraulic cylinder, a piston mounted in the cylinder for reciprocal movement, means for reciprocating the piston during swinging movement of a door in either an opening or a closing direction including a rotatable cam adapted to be attached to the door and a spring biased cam follower engageable .with the cam and connected to the piston for movement therewith, means including la one-way valve for admitting hydraulic fluid behind the piston during movement of the piston away from original position adjacent'one end of the cylinder, a first fluid escape passage connected to said one end of the cylinder, a second fluid escape passage connected intermediate the ends of the cylinder adapted to be uncovered by the piston Yduring movement away from original position, and valve means for controlling the flow of fluid through said escape passages.

'4. In a door check, rotatable cam means for attachyment to a door for movement therewith, spring means in both axial directions during movement of the cam means in either direction away from door closing position and for repeating the sequential movement of the piston in both directions during return movement of the rotatable cam means to door closing position, and means for controlling the hydraulic liuid pressure on the piston during the final lphase of the sequential movement of the piston in both directions to check opening and closing movement of the door.

5. ln a door check, a hydraulic cylinder, a reciprocable piston in the cylinder, means to move said piston rst in one direction and then in the other direction during opening movement and also during closing movement of the door including a rotatable member driven by door movement, a one-way valve for admitting hydraulic fluid to the cylinder during said piston movement in said one direction, a fluid escape .passage connected to said cylinder for discharge of hydraulic fluid therefrom during movement of said piston in said other direction, a. flow control valve for said escape passage controlled by said rotatable member, and an auxiliary escape passage by-passing said flow control valve.

6. ln a door check, a rotatable member driven by door movement, a hydraulic cylinder, a reciprocable piston in the cylinder, means responsive to rotation of said rotatable member to effect movement of said'piston first yin one direction and then in the other direction during opening movement and also during closing movement of the door, a one-way valve for admitting fluid to the cylinder during piston movement in said one direction, a uid escape passage connected to said cylinder for releasing pressurized fluid therefrom, an adjustable metering valve in said escape passage, a flow control valve for said escape passage controlled by said rotatable member and operable to block said escape passage during final opening movement of the door, an auxiliary escape passage lay-passing said ow control valve, and a second adjustable metering valve in said auxiliary escape passage.

7. In a door check, a hydraulic cylinder, a reciprocable piston in the cylinder, a cam rotated by door movement and having a pair of angularly spaced lobes, a cam follower engageable with the piston and engaging said cam lobes successively during door movement and thereby displacing the piston to effect piston movement rst in one direction and then in the other direction during either opening movement or closing movement of the door, a valve for admitting hydraulic fluid into the cylinder during piston movement in said one direction, a uid escape passage connected to said cylinder for discharge of hydraulic uid therefrom during movement of said piston in said other direction, an adjustable ow metering valve in said escape passage, a ow control Vvalve controlled by said cam for blocking said escape passage responsive to opening movement of the door, an auxiliary escape passage by-passing said ow control valve, and a second adjustable ow metering valve in said auxiliary escape passage.

8. In a door check, a cam rotated by door movement, a hydraulic cylinder, a reciprocable piston in the cylinder, means responsive to movement of said cam to move said piston first one way to draw hydraulic fluid into the cylinder and then in the other way to eject uid from the cylinder during either opening movement of the door or closing movement of the door, a reciprocable slide, means to move said side in one direction when the door closes and in the other direction when the door opens, a lluid escape passage connected to said cylinder, a ow control valve operated by movement of said slide Vin said other direction to block said escape passage, and an auxiliary escape passage by-passing said flow con- Atrol valve.

9. In a door check, a rotatable cam driven by door movement, a reciprocable slide, means to move said slide in one direction during door closing and in the other direction during door opening, a hydraulic cylinder, a reciprocable piston in the cylinder, a biased cam follower engageable with said cam and connected to said piston, -means on said slide engageable with said piston, said Vpiston being displaceable successively by the cam follower and the slide for movement in one direction and then in the other direction during door opening movement and being displaceable successively by the slide and the cam follower for movement in one direction and then in the other direction during door closing movement, a one-way valve for admitting hydraulic uid into -the cylinder during piston movement in said one direction, a fluid escape passage connected to said cylinder, a

Viow control valve in said escape passage operated by movement of said slide to block said escape passage during door opening movement, and an auxiliary escape passage by-passing said flow control valve.

10. In a door check, a cam rotated by door movement, a hydraulic cylinder, a reciprocable piston in the cylinder controlled by the cam and movable first one way to draw hydraulic fluid into the cylinder and then the other way to eject fluid from the cylinder during either opening movement of the door or closing movement of the door, a reciprocable slide, means to move said slide in one direction when the door closes and in the other direction when the door opens, a iluid escape passage connected to said cylinder for releasing compressed luid therefrom, an adjustable flow metering valve in said escape passage, a control valve operated by movement of said slide in said other direction to block said escape passage, an auxiliary escape passage by-passing said valve, and a second adjustable ow metering valve in said auxiliary escape passage.

1l. In a door check, a hydraulic cylinder, a reciprocable piston in the cylinder, a rotatable cam driven by door movement and actuating the piston to control piston movement in one direction during the initial phase of door opening and in the other direction during the nal phase of door closing movement, a reciprocable slide driven by door movement and engageable with the piston to control piston movement in said other direction dur- ,ing the final phase of door opening movement and in said one direction during the initial phase of door clos- -ing movement, a one-way valve for admitting hydraulic fluid into the cylinder during piston movement in said one direction, a fluid escape passage connected to said cylinder, an adjustable flow metering valve in said escape passage, a flow control valve in said escape passage operated by movement of said slide in said other direction to block said escape passage, an auxiliary escape passage by-passing said flow control valve, and a second adjustable ow metering valve in said auxiliary escape passage.

l2. In a door check, a rotatable cam driven by door movement, a hydraulic cylinder, a reciprocable piston in the cylinder, means responsive to movement of said cam to move said piston first in one direction and then the other direction during either opening movement of the door or closing movement of the door, a one-way valve for admitting hydraulic uid to the cylinder during said piston movement in one direction, a rst escape port in said cylinder spaced in said other direction from the extreme position of said piston in said other direction, a second escape port in the cylinder at an intermediate point in the piston stroke, a fluid escape passage connected to said ports, an adjustable ow metering valve in each of said ports for regulating flow to said escape passage, a ow control valve controlled by said cam for blocking said escape passage responsive to opening movement of the door, an auxiliary escape passage by-passing said valve, and an adjustable ow metering valve in said auxilary escape passage.

13. In a door check, a hydraulic cylinder, a reciprocable piston in the cylinder having a cam follower, a cam rotated by a door movement and having spaced lobes separated by a valley successively drivingly engageable with the cam follower to control movement of the piston iirst in one direction and then in the other direction during either opening or closing movement of the door, a oneway valve for admitting hydraulic fluid into the cylinder during piston movement in said one direction, a reciprocable slide, means to move said slide in said other direction when the door is opened, a spring for returning the slide in said one direction as the door closes, a uid escape passage connected to said cylinder for releasing pressurized fluid therefrom, an adjustable ow metering valve in said escape passage, a control valve for said escape passage operated by movement of said slide in said other direction to block said escape passage, an auxiliary escape passage by-passing said control valve, and a second adjustable flow metering valve in said auxiliary escape passage.

14. In a door check, a hydraulic cylinder, a reciprocable piston in the cylinder, a cam rotated by door movement and having a pair of angularly spaced lobes separated by a valley, said lobes successively actuating the piston to move the piston in one direction and then in the other direction during either opening or closing movement or the door, a spring urging the piston in said one direction, a one-way valve for admitting hydraulic fluid into the cylinder during movement of the piston therein in said one direction, a reciprocable slide, means to move said slide in said other direction during opening of the door, a spring urging the slide in said one direction, a first escape port in said cylinder located in front of said piston at its extreme extended position, a second escape port in said cylinder located intermediate the ends of the piston stroke, a fluid escape passage connected to said ports, an adjustable flow metering valve in each of said escape ports for selectively regulating flow therethrough to said escape passage, a discharge control valve for said escape passage operated by movement of said slide in said other direction to block said escape passage, an auxiliary escape passage by-passing said discharge valve, and a second adjustable llow metering valve in said auxiliary escape passage.

15. In a door check, a hydraulic cylinder, a reciprocable piston in the cylinder, a cam rotated by door movement and having spaced lobes, said lobes successfully actuating the piston to control movement of the piston rst in one direction and then in the other direction durng either opening lor closing movement of the door, a

one-way valve for admitting hydraulic fluid into the cylinder during piston movement in said one direction, a reciprocable slide, means to move said slide in said other `direction when the door Vis opened, a spring for returning the slide in said one direction as the door closes, a fluid escape or discharge passage connected to said cylinder and open at one end for releasing pressurized iiuid therefrom, an adjustable flow metering valve in said escape passage, a discharge control valve engageable by said slide and insertable into the open end of said discharge passage to shut off tlow therein responsive to movement of said slide in said other direction, said discharge control valve having a tapered bleed oriiice progressively covered by said discharge passage during insertion of said valve therein to throttle flow in said discharge passage gradually, an auxiliary escape passage by-passing the end of said discharge passage, and a second adjustable flow metering valve in said auxiliary escape passage.

16. In a door check, a hydraulic cylinder, a reciprocable piston in the cylinder having a cam follower, a doordriven rotatable cam engageable with said follower having a pair of angularly spaced lobes separated by a valley, a spring biasing said cam follower toward said cam, whereby said piston is moved rst in one direction and then in the other direction during either opening or closing movement of the door, a one-way valve for admitting hydraulic iluid into the cylinder during movement of the piston therein in said one direction, a reciprocable slide, means to move said slide in said other direction during opening of the door, a spring urging the slide in said one direction, a rst escape port in said cylinder located in front of said piston at its extreme extended position, a second escape port in said cylinder located intermediate the ends of the piston stroke, a uid escape or discharge passage connected to said port and open at one end, an adjustable flow metering valve in each of said escape ports for selectively regulating iiow therethrough to said escape passage, a control valve engageable by said slide and insertable into the open end of said discharge passage to shut oif iiow therein responsive to movement of said slide in said other direction, said control valve having a tapered bleed orifice progressively covered by said discharge passage during insertion of said valve therein to throttle ow in said discharge passage gradually, an auxiliary escape passage by-passing said control valve, and a second adjustable flow metering valve in said auxiliary escape passage.

17. In a door check, a hydraulic cylinder, a reciprocable piston in the cylinder, a rotatable cam driven by door movement and displacing the piston to effect piston movement in one direction during the initial phase of door opening and in the other direction during the final phase of door closing movement, a reciprocable slide, means to move said slide in said other direction during opening of the door and in said one direction during closing of the door, said slide being engageable with the piston to eiect piston movement in said other direction during the iinal phase of door opening movement and in said one direction during the initial phase of door closing movement, a one-Way valve for admitting hydraulic iluid into lthe cylinder during piston movement in said one direction, a rst escape port in said cylinder spaced in said other direction from the limit of movement of said piston in said other direction, a second escape port in the cylinder at an intermediate point inthe piston stroke, a uid escape passage connected to said ports, an adjustable flow metering vaive in each of said ports `for regulating flow to said escape passage, a flow control valve operated by movement of said slide for blocking said escape passage responsive to opening movement of the door, an auxiliary escape passage by-passing said flow control valve, and an adjustable flow metering valve in said auxiliary escape passage.

18. In a door check, -a hydraulic cylinder, a reciprocable piston in the cylinder, a rotatable cam driven by door movement and displacing the piston to control piston movement in one direction during the initial phase of door opening and in the other direction during the final phase of door closing movement, a reciprocable slide, means to move said slide in said other direction during opening of the door and in said one direction during closing of the door, said slide being engageable with the piston to eifect piston movement in said other direction during the linal phase of door opening movement and in said one direction during the initial phase of door closing movement7 a one-way valve for admitting hydraulic iluid into the cylinder during piston movement in said one direction, a fluid escape passage connected to said cylinder and open at one end for releasing pressurized iiuid therefrom, an adjustable flow metering valve in said escape passage, a discharge control valve engageable by said slide and insertable into the open end of said discharge passage to shut off flow therein responsive to movement of said slide in said other direction, said discharge control valve having a tapered bleed orice progressively covered by said discharge passage during insertion of said control valve therein to throttle flow in said discharge passage gradually, an auxiliary escape passage by-passing the open end of said discharge passage, and a second adjustable ow metering valve in said auxiliary escape passage.

19. In a door check, a hydraulic cylinder, a reciprocable piston in the cylinder, a rotatable cam driven by door movement and displacing the piston to control piston movement in one direction during the initial phase of door opening and in the other direction during the final phase of door closing movement, a reciprocable slide, means to move said slide in said other direction during opening of the door and in said one direction during closing of the door, said slide being engageable with the piston to eiect piston movement in said other direction during the final phase of door opening movement and in said one direction during the initial phase of door closing movement, a one-way valve for admitting hydraulic fluid into the cylinder during piston movement in said one direction, a iirst escape port in said cylinder spaced in front of said piston at its extreme extended position, a second escape port in said cylinder spaced intermediate the ends of the piston stroke, a fluid escape or discharge passage connected to said ports and open at one end, an adjustable flow metering valve in each of said escape ports for selectively regulating ow therethrough to said escape passage, a control valve engageable by said slide and insertable into the open end of said discharge passage to shut oi ilow therein responsive to movement of said slide in said other direction, said control valve having a tapered bleed orice progressively covered by said discharge passage during insertion of said valve therein to throttle flow in said discharge passage gradually, an auxiliary escape passage by-passing said discharge valve, and a second adjustable flow metering -valve in said auxiliary escape passage.

20. In a door check for checking the movement of a door during final opening movement and also during iinal closing movement of the door, a hydraulic cylinder, a piston mounted in the cylinder for reciprocal movement, means biasing the piston toward one end of the cylinder', rotatable cam means adapted to be connected to the door for movement therewith, cam follower means for actuating the piston responsive to movement of the cam means with the door against the opposition of said biasing means, said cam means having spaced portions for moving the piston toward the other end of the cylinder during iinal movement of the door in either a closing direction or an opening direction, a fluid reservoir, conduit means communicating with said cylinder and reservoir and including a fluid escape passageway between said other end of the cylinder and the fluid reservoir, and

"11 12 means forrestrctng said passageway during movement 578,084 Lash Mar. 2, 1897 of the piston toward said other end of the cylinder. 1,114,216 Wright Oct. 20, 1914 1,832,699 Garrison Nov. 17, 1931 References Cited in the le of this patent 2,528,904 Ngrbaue Nov, 7, 1950 UNITED STATES PATENTS 5 2,585,625 Carlson Feb. 12, 1952 366,711 Bardsley july 19, 1887 2,603818 Carlson July 221 1952

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