US 3548444 A
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Dec. 22, 1970 o. w JACOBUS ETA!- 3,548,444 DOOR CLOSURE DEVICE WITH TIME DELAY MEANS Filed Feb. 28, 1969 SN w mm .a m m CL A o c T- N T IW A w, m M W E United States Patent 3,548,444 DOOR CLOSURE DEVICE WITH TIME DELAY MEANS Dwight W. Jacobus and Eugene N. Callahan, Louisville,
Ky., assignors to General Electric Company, a corporation of New York Filed Feb. 28, 1969, Ser. No. 803,315 Int. Cl. E05f 1/08 US. Cl. 16--78 Claims ABSTRACT OF THE DISCLOSURE A door closure device for both slowing the closing movement of a door and thereafter holding the door in its closed position includes a spring biased cable drum closure means designed to provide a positive latching force when the door is closed and an inertia wheel operatively connected to the drum by a one way clutch for slowing the initial closing movement of the door.
BACKGROUND OF THE INVENTION In its simplest form, a door closure device including a spring biased cable comprises a cable or similar flexible member wound on a drum with its free end connected to the door. The energy stored in the spring during opening of the door provides the force necessary to close the door. A disadvantage of such a device is that the wound spring may cause an initial closing movement of the door which is quite fast While the available energy remaining in the spring when the door reaches its closed position may be too small to assure complete closing of the door. In addition the force required to open the door increases with the degree of door opening due to the increasing resistance of the spring as it becomes wound or stressed.
Various means have been used or proposed for modifying the action of such cable drum closure devices. However, the improved cable drum closure devices have generally been designed for specific applications or in other words to meet particular closure requirements. For example, it has been proposed to incorporate a brake band in the device to brake, or in other words slow, the closing movement of the door as described in Pat. 3,332,638, Jessup et al. A structure of this type must be accessible for periodic adjustment of the brake and is not suitable for use under moist or wet ambient conditions.
A specific application of a door closure device in which the device must provide rather unique operating characteristics is the application to the door employed for closing an ice passageway in a household refrigerator of the type described and claimed in the copending application Ser. No. 669,234, filed Sept. 20, 1967 in the names of D. W. Jacobus and W. C. Bodong and assigned to the same assignee as the present invention. Such a door must be openable by the application of a small or minimum force and the closure device should close the door to completely seal the passageway upon the removal of that force. A major requirement is that the device operate in such a manner that the door will not close before the dispensed ice pieces enter the passageway serviced by the door.
SUMMARY OF THE INVENTION The present invention has as its primary object, the provision of a door closure device of the cable drum type designed to require a minimum force for opening the door, to provide a substantial sealing force when the door is closed and-to provide a slow initial closing movement of the door.
More specifically, there is provided in accordance with the present invention a door closing device comprising a cable drum including a first cable winding surface and a second cable winding surface spaced a greater distance from the drum axis than the first surface. A cable having its free end connected to the door is trained over the first surface and then over the second surface and other end secured to the drum. A spiral spring is provided for rotating and biasing the drum to the cable wound position in which the cable is in engagement with the first surface to provide a maximum sealing force on the door when the door is in its closed position. For the purpose of delaying or slowing the initial closing movement of the door, the device includes inertia means operably connected to the cable drum only when the drum is rotating in its cable winding direction.
BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing:
FIG. 1 is a vertical sectional view of a portion of a refrigerator incorporating the present invention;
FIG. 2 is a horizontal plan view, partly in section, illustrating certain details of construction of the closure device of the present invention, the section being taken generally along line 2-2 of FIG. 3;
FIG. 3 is a vertical sectional view of the device along line 33 of FIG. 2; and
FIG. 4 is a sectional view taken along line 44 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT While the closure device of the present invention may have other applications, it will be specifically described in its preferred application to the operation of an ice passage door of the type described in the aforementioned Jacobus and Bodong application. Such a door indicated by the numeral 1 in FIG. 1 of the drawing is provided for closing an ice passageway 2 in a main freezer door 3 forming part of a household refrigerator. The door 1 is pivotally mounted by hinge means 4 on the inner surface of the main door 3 and when the door is opened by application of pressure to a push rod 5 to the dotted line position as illustrated in FIG. 1, a chute 6 movable with the door 1 and normally positioned within the ice passageway 2 is in a position to receive ice pieces discharged from an outlet 7 forming part of a motor driven ice dispenser of the type more fully described and claimed in Pat. 3,422,994, Alvarez, issued J an. 21, 1969.
More specifically pressure on the push rod 5 operates through a crank arm .member 9 engaging the outer surface of the door 1 to move it to its open position. Further, as described in the aforementioned Jacobus and Bodong application rearward movement of the rod 5 actuates a switch 10 which controls the energization of the ice dispensing means for dispensing ice pieces through the outlet 7. For a more detailed description of the elements thus far described, reference is again made to aforementioned Jacobus and Bodong application.
It will be seen that when the door 1 is opened by pressure on the push rod 5 and the ice dispenser energized by the switch 10, the ice pieces discharged from the outlet 7 drop onto the chute 6 and pass through the passage 2 into a glass or other receptacle supported below the outlet end of that passage. In order to prevent ice pieces which are in the process of being discharged from the outlet 7 from being trapped between the door 1 and the inner surface of the main freezer door 3 or from missing the chute 6 due to a too rapid closing of the door 1, it is desirable to provide a time delay in the closing movement of the door 1 followin the removal of pressure on rod 5 and the deenergization of the ice dispensing means.
In accordance with the present invention, this door closure device, generally indicated by the numeral 14,
comprises a metal frame member forming the bottom wall 16 and the front and rear walls 17 and 18 of a housing which is completed by a plastic cover member 19 forming the top wall 20 and the opposed housing side walls 21. The closure member 14 is mounted within the insulated space of the freezer door 3 and is supported on the inner wall 21 of the freezer door by means of a mounting plate 22 secured to the housing front wall 17 and to the inner freezer door wall 21. An axle 24 extends perpendicular to and upwardly from the central portion of the bottom wall 16 with the upper end thereof, as illustrated in FIG. 3 of the drawing, being engaged by the top wall 20' of the member 19.
A cable drum 25 including a cylindrical hub 26 is rotatably mounted on the lower end of the axle 24. This drum includes an upper disc shaped member 27 and a lower disc shaped member 28 with the lower member 28 including a plateau 29 (FIG. 4) spacing the two discs from one another, the two discs being interconnected by means of a rivet 30 extending through this plateau region. The upper disc member 27 is also provided with an arcuate downwardly extending projection 31 passing through a cooperating arcuate slot 32 in the lower disc 28, the surface of this projection 31 being spaced a greater distance from the drum axis represented by the axle 24 than is the outer surface of the symmetrical hub 26.
This arcuate projection 31 and a small arcuate section or segment 33 of the hub 26 define cable winding surface portions of different moment arms for a cable 34. While they are shown as separated surfaces, which facilitate the manufacture and assembly of the device, it will be obvious that they could be interconnected to form a single continuous and somewhat spiral surface. More specifically one end of the cable 34 is anchored, as illustrated by the numeral 35, to one end of the arcuate projection 31, and when the cable drum is in its door closing position the cable is trained over the remaining arcuate surface of the projection 31 and passes over the opposite end 36 thereof into contact with the segment 33 of the hub 26. The cable then passes through an eyelet 38 in the front wall 17 of the housing and has its other end 40 connected, as illustrated in FIG. 2, to the door 1.
A spiral spring 41 surrounding the lower end of the hub 26 has one end anchored to the hub and the other end hooked over a tab 43 on the base 16 in such a manner that the spring biases rotation of the drum in the clockwise direction, that is, in the direction of rotation which winds the cable onto the drum as shown in FIG. 4.
The upper disc 27 of the cable drum also includes an upwardly projecting peripheral flange 45 having gear teeth on the inner surface thereof to form an internal gear 46 which is part of a planetary gear system for providing a one way time delay means controlling the operation of the drum 25.
This time delay means also includes an idler arm '50 rotatably mounted on the axle 24 within the area encompassed by the internal gear 46, and carrying a gear set or train including an idler gear 51 meshing with the interior gear 46. The gear 51 meshes with a small gear 52 coaxial and rotatable with a relatively large gear 53 which in turn meshes with a gear 54 formed on the lower hub portion of an inertia wheel 55 rotatably supported on the upper end of the axle 24.
A spring clutch 56 including, as is shown in FIG. 3 of the drawing, a coiled portion surrounding the axle 24 within the hub portion of the idler arm 50 and having one end 57 secured to the idler arm provides means whereby the idler arm 50 can turn freely on axle 24 in a counterclockwise direction as viewed in FIG. 2 of the drawing when the door is being opened but is prevented from turning freely in the opposite direction when the door is closing.
When the door 1 is in its closed position the cable 34 as shown in full lines in FIG. 4, extends through the eyelet 38 into engagement with the first winding sur- 4 face defined by the arcuate portion 33 of the hub 26 and from there passes over the end 36 of the arcuate projection 31 forming a second cable winding surface having a greater radius than the first surface 33. The surface 33 is relatively short and has an arcuate length of less than preferably about 30. In this position of the drum, the spring 41 provides sufficient tension to the drum to maintain the door 1 in closed sealing engagement with the gasket 60 on the inner surface of the freezer door 3.
As the door is opened by application of pressure to push rod 5, the cable 34 is pulled through the eyelet 38 and rotates the drum 25 in a counterclockwise direction as viewed in FIG. 4. Since the clutch 56 is disengaged, the inertia wheel is disconnected so that the door can be rapidly opened with a minimum force. When the segment 31 moves to a position in which the cable 34 leaves the hub 26, the moment arm is changed from that represented by the radius of the hub 26 to that represented by the distance of the segment 31 from the drum axis further decreasing the force required to overcome the increased tension of the winding spring. The opening movement of the door 1 is limited by engagement of a downwardly extending projection 61 on the drum with a stop 62 on the housing base or bottom wall 16 at which time the spring is wound to store the maximum available spring energy.
When pressure on the push rod 5 is removed, the door is free to be returned to its closed position by the tension in the spring 41. It will be seen that in the absence of any means for delaying or slowing down the return movement of the door, the tension in the wound spring 41 and the relatively large moment arm of the cable contacting surface as defined by the arcuate projection 31 would cause the door to move from its open to its closed position very quickly. Under such conditions any ice pieces in the process of being discharged through the outlet 7 may not reach the chute 6 in time to be discharged through the passage 2.
The time delay means for slowing the return movement of the door 1 to its closed position comprises the inertia wheel 55 and the gear drive means connecting this inertia wheel to the drum 25. The spring clutch 56, which is unidirectional in its operation, provides means for connecting the inertia wheel 55 through the gear train to the drum only during rotation thereof in the cable winding direction that is in a clockwise direction. The clutch prevents rotation of the idler arm in this direction so that the drum cannot rotate without driving the inertia wheel 55 through the gear train. In the illustrated mechanism, the gears provide a connection such that the inertia wheel rotates through 36 revolutions for each revolution of the drum. This gear ratio and the weight of the inertia wheel '55 determine the closing rate of the door. It is initially relatively slow due to the fact that the inertia wheel requires some time to come up to speed.
When the cable engages the arcuate segment or surface 33 as the door approaches its closed position, its relatively short moment arm provides an increased latching force to assure sealing engagement of the door with the gasket 60. During this same period the inertia wheel which has come up to speed continues to spin for a short time adding to this latching force since under such conditions the inertia wheel 55 is in effect applying a force driving the drum in its clockwise direction.
From the above description, it will be seen that the Closure device provides door return forces which are sufficient to seal the door against the gasket 60 and which include those provided by the engagement of the cable with smaller moment arm surface 33 during the final period of rotation and the force supplied by the continued rotation of wheel 55. In other words, the initial slowing of the return movement of the door does not materially affect the final available sealing forces. In addition the functioning of the closure device is substantially independent of the environmental conditions and is particular- 1y suited for use in the low temperature and possibly moist conditions prevalent adjacent the inner surface of a freezer door.
While the invention has been described with reference to specific embodiment, it is to be understood that it is not limited thereto and it is intended by the appended claims to cover all such modifications as fall within the scope of the invention.
What we claim as new and desire to secure by the Letters Patent of the United States is:
1. A door closing device for closing a door comprising:
a cable drum including a cable winding surface including a first portion and a second portion spaced a greater distance from the drum axis than said first portion;
a cable having one end secured to said drum and trained over said second portion and then over said first portion with the other end secured to said door;
spring means for rotating said drum in a winding direction to a position in which said cable is wound over said portions for holding said door in its closed position with a portion of said cable engaging said first portion;
an inertia means journalled on the same axis as said drum; and
means for connecting said inertia means to said drum only when said drum is rotating in a winding direction to thereby delay closing movement of said door.
2. The device of claim 1 in which the length of said first surface is substantially less than the length of said second surface. T
3. The device of claim 1 in which both of said surfaces are arcuate surfaces having the same axes as said axle.
4. The device of claim 3 in which said surfaces are separated from one another.
5. The device of claim 4 in which said first surface has an arcuate length of less than 90.
6. The device of claim 5 in which said first surface has an arcuate length of about 30.
7. The device of claim 1 in which said cable engages said first surface only when said door approaches its closed position.
8. A door closing device for closing a door comprising:
a frame member including an axle;
a cable drum journalled on said axle and rotatable about the axis thereof;
said drum including a first cable winding surface and a second winding surface spaced a greater distance from said axis than said first surface;
a cable having one end secured to said drum and trained over said second surface and then over said first surface with the other end secured to said door;
spiral spring means for rotating said drum in a winding direction to a position in which said cable is wound over said surfaces for holding said door in its closed position with said cable engaging said first surface; and
means for slowing the closing movement of said door from an open position comprising an inertia wheel journalled on said axle and clutch means for connecting said wheel to said drum only when said drum is rotating in a winding direction.
9. The device of claim 8 in which said slowing means comprises a planetary gear system interconnecting said drum and said inertia wheel and including an idler arm and gear train assembly journalled on said axle between said drum and said inertia wheel.
10. The device of claim 9 in which said clutch comprises a clutch spring coiled about said axle and having one end fixed to said idler arm for preventing rotation of said idler arm and gear assembly with said drum when said drum is rotating in its winding direction and thereby connecting said drum to said inertia wheel through said gear train.
References Cited UNITED STATES PATENTS 346,296 7/1886 Lewy l6-78 684,742 10/ 1901 Bromley l6-78 1,186,720 6/1916 Westhofi 16-78 DONALD A. GRIFFIN, Primary Examiner US. Cl. X.R.