US 3346992 A
Description (OCR text may contain errors)
A. LODGE Oct. 17, 1967 3,346,992 MECHANISM FOR SWINGING AND LIFTING DOORS AND THE LIKE Filed Aug. 26, 1965 2 Sheets-Sheet l ilbmmhrr Oct. 17, 1967 LODGE MECHANISM FOR SWINGING AND LIFTING DOORS AND THE LIKE 2 Sheets-Sheet 2 INVENTOR.
Filed Aug. 26, 1965 Patented Oct. 17, 1967 3,346,992 MECHANISM FDR SWINGING AND LE TING DOORS AND THE LIKE Alvin Lodge, Erie, Pa, assignor to American Sterilizer Company, Erie, Pin, a corporation of Pennsylvania Filed Aug. 26, 1965, Ser. No. 482,765 13 Claims. (Cl. 49-255) ABSTRACT OF THE DISCLOSURE The mechanism disclosed is made up primarily of a screw and nut arrangement, one of which is attached to a door and the other to a motor. The motor arrangement mounted on the sterilizer drives the screw so that it swings the door until the door strikes an obstruction. Then, the screw raises the door by a jamming action on the threads of the nut.
The lifting mechanism is so designed that when the motor starts to rotate a gear to which the nut is attached, the door will swing open until it strikes the edges of the pit or until a follower strikes the edge of a cam slot. Then the nut mechanism will move up the incline of the threads and thus will lift the door until the door clears the top of the pit or until the follower clears the top of the slot and further rotation of the motor swings the door to full open position.
This invention relates to mechanisms and, more particularly, to mechanisms suitable for lifting and swinging a door, for example, a sterilizer door.
It is, accordingly, an object of the present invention to provide an improved door opening mechanism.
Another object of the invention is to provide a door opening mechanism which is simple in construction, economical to manufacture, and simple and efiicient to use. Still another object of the invention is to provide an improved mechanism for accomplishing a novel combination of rotary and axial motions.
With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawing and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions, and minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention.
In the drawings:
FIG. 1 is a partial isometric view of a door and operat ing mechanism according to the invention shown supported in a pit;
FIG. 2 is a partial front view of the mechanism shown in FIG. 1 with the door in closed position and the locking mechanism actuated;
FIG. 3 is a view similar to FIG. 2 showing the locking mechanism released;
FIG. 4 is a top view of the lifting mechanism showing the door in three separate positions in phantom lines;
FIG. 5 is a partial cross sectional view taken on line 55 of FIG. 2;
FIG. 6 is a view partly in cross section taken on line 6--6 of FIG. 5; and
FIG. 7 is an enlarged view of the cam and follower arrangement taken on line 77 of FIG. 6.
Now with more particular reference to the drawings, a door 10 is shown with a power lift assembly 11 supporting it on a sterilizer 30 or the like. A hinge assembly 12 supports the door for swinging on the sterilizer 3'0 which may be a sterilizer of an ordinary steam chamber design. The sterilizer has the cars 31 fixed to it and they receive a hinge pin 17. The hinge pin 17 is also received in brackets 33 which are fixed to the hinge 34. Thus, pin 17 can slide up and down in the ears 31 when the door 10 is lifted and the door 10 can also swing around the pin 17.
The door 10 has rollers 35 fixed at its lower edge which will engage the edge of a pit 36 when the door is in lowered position and may engage the side walls of the pit when the door is swung upwardly. The door has a locking mechanism 26 having arms 25 which may be operated to lock the door in closed position. This locking arrangement is conventional and may be generally of the type disclosed in patent application, Ser. No. 2,592,705.
The door lifting and operating mechanism is more specifically shown in FIGS. 5, 6, and 7. These figures show the lifting assembly 11 attached to the door 10. A screw shaft 14 has a spiral thread 21 thereon which is in the form of a spiral groove that has a pitch angle that will allow it to operate in the manner desired. A pitch angle of thirty degrees has been found to be satisfactory. The screw 14 is fixed to the bracket 24 and bracket 24 is in turn fixed to the door. The bracket 24 has a downwardly extending leg indicated in which the follower stud 28 is received. Follower stud 28 has a roller 29 on it which is received in the cam slot 40 in the plate 41. The plate 41 is fixed to the frame of the sterilizer.
It will be noted that slot 49 has a generally horizontal portion 42 and a vertical portion 43 so that the roller 29 will first move horizontally and then upwardly to follow the slot and then move along the top edge 44 of the plate 41. Since door 10 is fixed to bracket 24, the door 10 will first swing, then raise, then swing again.
The gear 18 is received between the brake linings 19 which are, in turn, fixed to the brake shoe arrangement 46 to provide a safety slip clutch arrangement to protect the mechanism in case of overload. The brake shoes are themselves rotatably received between anti-friction bearings 20 and they freely rotate therein. These brake shoes are keyed to the lifting nut 22. The motor 23 drives the shaft 48 and, from it, the gear 49 and thence through the shaft 50 to the worm gear 51 which, in turn, drives the gear 18.
In operation, when the door is in the closed position, the motor 23 will be started. This will drive gear 18 and will rotate the nut 22 with the screw 14 and will swing the door out until the roller 29 strikes the edge of the vertical part 43 of the slot or until the wheel 35 strikes the edge of the pit. The nut will then jam against the spiral threads on the shaft 14 and will force the nut 22 to move up along the threads until the roller 29 rides above the surface 44. Then the nut will again turn with the screw and swing the door to open position.
The foregoing specification sets forth the invention in its preferred practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood i broadly novel as is commensurate with the appended claims.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A mechanism for rotating a work member and for swinging said member in a predetermined sequence comprising a rotatable screw member,
a spiral groove in the outer periphery of said screw member,
a nut member,
means to rotate said nut member,
thread means conecting said nut member to said screw member,
a fixed member,
cam means on said fixed member,
cam means on said screw in operative engagement with said cam means on said fixed member for guiding said screw in a predetermined sequence of axial and rotary motion,
and means on said screw for connecting said Work member thereto.
2. The mechanism recited in claim 1 wherein said thread means comprises a spiral groove in said nut member,
balls in said grooves,
each said ball being disposed half in one said groove and half in the other said groove.
3. In combination, a door and opening means on said door,
tached to said chamber, and an opening mechanism for said door,
said door being attached to said chamberby means of a vertically extending hinge pin,
hinge members slidably supported on said pin,
said door being fixed to said hinge members,
and means connected between said door and said chamber to swing said door toward open position until it engages an obstruction, then to lift said door until said door clears said obstruction, then to swing said door to full open position.
5. The combination recited in claim 4 wherein said means to swing said door and to lift said door comprises a motor,
a nut connected to said motor,
a screw threadably received in said nut,
means on said screw to connect to a member to be moved in a predetermined path,
and guide means for guiding said member in said predetermined path as said screw is forced to rotate and move axially by said nut, driven by said motor.
6. In combination, a sterilizer chamber, a door swingably supported on said chamber, and opening means to swing said door partly open, then move saiddoor upwardly, and then swing said door fully open,
said opening means comprising a screw,
nut means on said screw,
means to drive said nut,
means attaching said door to said screw,
fixed cam means having a contour,
and follower means on said screw engaging said cam means,
said screw rotating and moving axially when driven by said nut whereby said door is moved upwardly and swung in accordance with said contour of said said door being attached to said screw,
said nut means being adapted to move said screw axially so that said door will move up to clear obstructions,
swing means on said door, said nut being further connected to said swing means on said door to swing over said obstructions.
8. In combination, a chamber, a door on said chamber, and opening means on said door to swing said door into engagement with an obstruction, then lift said door over said obstruction, and then swing said door fully open,
said opening means comprisingv a screw connected to said door and driven nut means on said screw,
said screw having means to move axially when said door is held against swinging and being adapted to swing said door when said door is free to swing.
9. In combination, a sterilizer chamber mounted in a shallow pit, a door swingably supported on said cham: her with the lower edge of said door below the top surface of said pit, and opening means for said door,
said opening means comprising a vertically extending screw attached to said door,
and a driven nut on said screw,
said nut connected-to said screw to move said screw axially to lift said door over said top surface of said pit when said door engages said pit,
said nut being adapted to swing said door therewith when said door is moved above said pit top surface.
10. The combination recited in claim 9 wherein said door has roller means on its lower edge adapted to engage the inside surface of said pit whereby said.
said follower means slidably engaging said slot whereby 1 said swinging member is urged to swing when said follower means moves in one said part of said slot,
said swinging member being urged to be lifted when said follower means moves in another part of said slot.
12. The mechanism recited in claim 11 wherein said means for supporting said member comprises a bracket having a part attached to said shaft and a part extending generally parallel there-to,
said follower being attached to said part of said bracket that extends parallel to said shaft.
13. The mechanism recited in claim 11 wherein said nut has a gear attachedzthereto and motor means is connected to said gear to rotate it.
References Cited UNITED STATES PATENTS 2/1943 Simpson 7489.15 4/ 1963 Linderfelt 49-317 X FOREIGN PATENTS 23,564 10/1902 Great Britain.
DAVID J. WILLIAMOWSKY, Primary Examiner.
J. K. BELL, Assistant Examiner.