US 2124349 A
Description (OCR text may contain errors)
G. HERBSTER DoR OPERATING DEVICE .July 19, 1,938.
Filed April 15, 1956 A2 Sheets-Sheet l QATTORNEY.
July 19, 1938. A yG HERBSTER 2,124,349
DOOR OPERATING DEVIE y Filed April l5, 1956 2 Sheets-Sheet 2 i ATTORNEY.
! parent froml Patented July 19, 1938 UNITED STATES PATENT OFFICE 8 Claims.
This invention relates to a device for opening and closing doors and the like and particularly to a treadle operated mechanism for both opening and closing doors of compartments such as cooking ranges, ovens and iceboxes by an voperator while. the operator is supporting in his hands articles to be placed within or removed from the compartment.
Specific additional problems are solved and advantages obtained by the use of the present invention in connection with downwardly swinging oven doors of domestic ranges, such as gas cooking ranges, or other relatively heavy doors having considerable inertia wherein problems other than those presented by the compartments in general are present. Accordingly, to more clearly present the problems, the present invention will be described speciiically in connection with a domestic gas range cooking oven wherein the oven door swings downwardly about its lower edge to a horizontal position to permit access to the in-v terior of the oven.
VOne of the objects of the present invention is to provide a treadle operated mechanism by which the oven door can be opened and closed selectively more conveniently so that the hands of the operator are free for other use and are not subjected to contact withl the heated parts of the range.
A correlativeobject is to effect rapid and free movement of the door from either an open or closed position almost to the opposite position with"effective buiiing of the movement during final movement into such opposite position so as to prevent excessive shocks and strains and resultant damage to the door and parts of the range which commonly result when oven doors are slammed closed or open.
A more specific object is to accomplish these results with an oven drop door which is spring seated in closed position while at the same time eliminating anyshocks due to rapid movement of the door by the spring.
Another object is to provide a dual treadle device'for thispurpose wherein, as either treadle is moved downwardly Yfor operating the door, the
other treadle is automatically raised to position for `the opposite operation.
.Other objects and advantages willbecome apthe following specification wherein reference yis made tothe drawingsv in which Fig. lis a perspective view of a domestic gas cooking range with the present invention installed for Ause in connection therewith;
Fig. 2`is an enlarged vertical fragmentary sectional v*View of the range with the present device installed and is taken on the plane` indicated by the lines 2-2 in Figs. 1 and 4, respectively;
Fig. 3 is a horizontal sectional view taken on La plane indicated bythe line 3-3 in Fig. 2;
Fig. 4 is a rear elevation of the operating mechanism and is taken on the plane indicated by the line 4-4 in Fig. 2, part of the associated range being shown in section;
Fig. 5 is a diagrammatic end elevation of the range illustrated in Fig. 1, showing the relativey position of the present mechanism and one operating vposition thereof; and
Fig. 6 is an enlarged longitudinal sectional View ofthe dual buffing device of the present invention.
In Fig. l'is illustrated a domestic gas cooking range I having a dual oven compartment, designated generally as 2, and having floors 2d and 2c which are closed at the front by a downwardly swinging 4comparatively heavy drop door 3.
- 'I'he range is supported ona suitable base frame 4 terminating at its lower edge in spaced relation above the floor of the room in which the rangeis located. As better illustrated in Figs. 2 and fi, the oven door 3 is pivotally connected adjacent its lower edge by means of a suitable pivot 5 to the frame of the range. The pivot or hinge 5 extends horizontally, lengthwise of therange, so that the door may swing thereabout from an upright closed position to a horizontal open position substantiallyl on a level with the floor 2c of the oven, the horizontal position being indicated by the dotted lines in Fig. 2. For mounting the door on the pivot 5, there are mounted in the interior of the door, 'at' each end, rigid supporting arms 6 which maybe spot welded to. the associated end walls of the door, internally thereof, the supports 6 receiving the pivot 5 at their lower ends. One' arm B and co-v operating parts are shown but it is to be understood that duplicate parts are used at opposite sides of the door and connected to the same treadle, later to be described.
Carried on and rigid with each support 6 is an arm 1 which is generally arcuate about pivot 5 as a center and provided near its free end with an abutment stop la.; The stop la is positioned so that, when the door is in open horizontal position, the stop will abut the margin oi the inner front wall 2b of the oven so` as to arrest farther downward movement of the door. A coil spring 8 is secured by one of its ends to the arm l; and the opposite end of the spring is connected to one of the frame members 9 of the range `at a point close to the interior wall surface of the front wall of the oven and near the oven floor so that the spring extends at a slight angle to the vertical when the door 3 is closed.
The spring 8 is tensioned suiciently in its normal condition when the oven door is closed to hold the oven door rmly in closed position yet permit it to swing outwardly readily and fully vent any explosive pressure that might occur within the oven. That end of the spring 8 which is connected to the arm 1 is fastened thereto preferably close to the stop 1a so that when the door is in the open horizontal position, the spring 8 is positioned substantially vertically with its ends close to a vertical plane through the pivot 5 as a resultof which its eifective lever arm is too small to permit the spring to overcome the weight of the door from the horizontal position even though the spring is considerably stressed.
In some cases, as will later be described, a spring sufiiciently strong for such swinging of the door from horizontal to upright position may be provided, but the structure above described is customary in some of the newer types of domestic cooking ranges and the present invention is adaptedfor utilizing these existing parts as part of its own structure.
. In this structure, the door 3 is held in upright closed position by the spring 8 when moved into that position but remains horizontal when moved to the latter position. Obviously, however, a spring of suflicient strength to hold the door firmly closed will, if the door is given a` slight upward swing, continue the swinging of thedoor to closed poistion so forcefully that severe shocks and strains on the door and adjacent parts of the range will result. Likewise, since the spring preferably is `too weak to raise the door from horizontal position, it is not sufficiently strong to relieve the shock in event the door is given a quick or forceful swing downwardly. In both cases, there is considerable inertia developed. Here again, the abutment 1a would be apt to damage the inner wall of the range or the door itself might be broken by the resultant shock. To overcome these objections and at the same time make possible the opening and closing of the door by foot operated mechanism so that the operator has both hands free to insert or withdraw articles from the oven, the mechanism now to be described is provided.
A link I0 is pivotally connected by one of its ends to the arm 1 so as to swing in a plane parallel to the arm, the pivotal connection thereof to the arm 1 being indicated at II. The link I0 preferably extends rearwardly from the plane of the oven door, andis pivotally connected at its opposite end by a pivot I2 to a lever I3. The
vlever I3, in turn, is pivotally connected by a pivot I4 to a stationary bracket I5 secured to the frame of the range, the pivot I4 being disposed rearwardly from the plane of the oven door. The opposite end of the lever I3 extends forwardly of the range substantially to the plane of the oven door but is positioned below the door, this end of the lever I3 being pivotally connected by a suitable pivot I6 to a tension rod or strip I1. The rod I1 extends downwardly from the pivot I 6 below the level of the oven ioor 2a.
At its lower end the tension rod I1 is pivotally connected by a pivot I8 to a treadle I9 which extends normal to the plane of the oven door andis connected at the end which is remote from the on the frame of the range.
plane of the oven door by a pivot 20 to a bracket 2l, the bracket being xedly secured in position The treadle I9 eX- tcnds forwardly from its pivotal connection with the rod and the outer end of the treadle is shaped to provide a pedal portion 22, the treadle extending in front of the forward face of the range at one side of the oven door and is positioned preferably near the center of the range so as to be readily accessible to the foot of the operator and in position to be operated without danger of the door striking the operator.
4Upon depressing the treadle by the foot of the operator, the treadle I9 swings about the pivot I3 downwardly and inwardly, thus drawing the rod I1. downwardly and rocking the lever I3 about the pivot Ill so that the upper end thereof is moved forwardly, The link l is suflciently .rigid to transmit this forward motion to the door 3 so that when the pedal 22 is fully depressed, the door 3 is swung downwardly to fully openY horizontal position.
In order to close the door, a suitable treadle means is provided and comprises a tension rod 2.4 which is pivotally connected at its upper end to the arm 1, preferably adjacent the stop 1a, as indicated at 25. The rod 24 extends downwardly below the floor level of the oven and passes between two guide rollers 2E which are mounted on the underside of a frame portion of the stove; At its lower end the rod 24 is ,turned outwardly toward the front of the range and extends beyond the front plane of the range alongside of the treadle I9 and pedal 22, the extending portion being formed to provide a pedal 21. Between the pedal V1 and the upper portion of the rod 24, the rod has a cam portion 28, this cam, in the form illustrated, being provided by suitably bending the rod 24. In the form illustrated, the cam portion 28 is shaped so that the pedal 21 travels in a vertical path, though by changing the cam the pedal 21 can be made to move into substantially concealed position when the door 3 is closed. This is accomplished where desired, by coaction ofthe rollers 26 and cam 28 such that the rod 24 is swung rearwardly as it moves downwardly so that when the oven door is closed the pedal 21 is onlyv slightly exposed,
but when the oven door is open the pedal 21 is readily accessible for foot operation.
Obviously, if an operator should apply his entire weight forcefully on either pedal, the movement of the relatively heavy door 3 would be so rapid that it would slam in extreme positions and probably break the hinges or damage the range dueveither to the continued application of the weight or the inertia of the door even after the weight was removed. At the same time it is necessary that the door move very freely only under the influence of the spring 8 at and ne'ar its closed position so that it may be held firmly but yieldably in closed position only by the spring 8. f
In order that the door may swing very rapidly and freely throughout the greater portion of its path of travel and yet be cushioned near the ends of its path of travel so that substantially no shock results and yet be capable of free and slower movement, into iinal position, a two-way buffer means is provided. In the form illustrated, the buffer means comprises a cylinder 30 i'lxedly secured to the frame of the range. As better illustr'ated in Fig. 6, a piston 3I is reciprocable in the cylinder and is operatively connected by a piston rod 32 to the door of the oven. In the form of the upper end of the rod is connected, as indi cated at 33, to a suitable pin 34 on the lever, a slight relatively pivotal movement being provided between the rod 33 and pin 34 to compensate for the slightly misaligned movement of the piston 3| and rod.
In the lower end of the cylinder 30 is a check valve 35 operable to admit air through a duct 36 into the cylinder at that end and to substantially prevent any movement of air in the opposite direction. A small spring seated check valve 31 is provided at the other end of the cylinder and is operable to admit air as indicated by the arrow 38 into the cylinder at the opposite end of the piston 3|. The piston preferably fits the cylinder with a loose fit, slight clearances, as indicated by 39, being provided between the piston and cylinder wall. Consequently, the air cannot pass around the piston rapidly. Thus, throughout the initial portion of its path of travel in either direction, the door operates the piston against air at normal pressure and no compression of the air results until the door is moved both rapidly and an appreciable distance along its path. Upon extremely rapid or forceful movement of the door, and especially toward the end of its path of travel, the air between the piston and the particular end of the cylinder cannot escape rapidly enough and becomes compressed so as to eliminate shock and cushion the door. Since this air can leak past the piston, slower movement of the door is not resisted in any way. Due to the operation of the valves, both ends of the cylinder are assured of a supply of air at all times. Thus the cushioning effect is in a direct proportional relationship to the speed of travel of the door and permits substantially free initial movement of the door either slowly or rapidly.
As heretofore stated, the spring 8 is connected close to the plane of the door and the pivot so that it acts so nearly through the pivot when the door is horizontal and `oilers substantially no resistance to the movement of the door. When the door is near upright position, however, the spring is disposed at a greater angle to a line from the point of connection 9 to the pivot 5 and may be capable of closing the door once it is swung partially toward closed position. With a buffer such as herein described utilized, this spring may be made much stronger for the purpose of closing the door once it is swung part way toward closing position.
Having thus described my invention, I claim:
1. In an apparatus having a compartment, a door hinged along one of the margins of the door for swinging about a horizontal axis to open and closed positions respectively, means yieldably urging the door to one of said positions, and pneumatic buffer means for resisting movement of the door in a direct proportional relationship to lthe speed of swinging of the door for preventing slamming thereof and operative to offer substantially no resistance to the swinging of the door when the door is moved more slowly toward said position, and operative during movement of the door along an intermediate portion of its path of travel to offer substantially no resistance to the movement thereof.
2. The combination with an apparatus having a compartment and a door hinged along one of its margins for swinging about a horizontal axis to open and closed positions respectively relative to `said compartment, and means yieldably urging the door to one of said positions, of buffer means` resisting movement of the door in a direct proportional relationship to the speed of. movement of the door to check toorapid movement of the door and operative to offer Ysubstantially no resistance to the swinging of the door when the door is moved more slowly toward said position.
3. The combination with an apparatus having a compartment and a door hinged along one of the margins of the door for swinging about a horizontal axis to open and closed positions re- Spectively, of buffer means for yieldably resisting movement of the door by force in a direct proportional relationship to the speed oi swinging of the door whereby too rapid swinging thereof is prevented, and operative to offer substantially no resistance to the swinging of the door when the door is moved more slowly toward one of said positions, and operative during movement of the door along an intermediate portion of its path of travel to offer substantially no resistance to the movement thereof. y
4. The combination with an apparatus having a compartment and a door mounted on a horizontal pivot for swinging about the pivot to open and closed positions, and means to urge said door to open and closed positions selectively, of double acting buffer means operative to resist movement of the door into iinal position in either direction when the door is moved rapidly toward such position and to permit free movement of the door to such positions consequent upon a reduced speed of travel ofthe door to said positions.
5. In an apparatus having a compartment open at one upright face, a door pivoted about a horizontal pivot for swinging movement upwardly to upright position in closing relation to the oven face and downwardly to horizontal position for permitting access to the interior of the compartment, a spring urging the door to closed position, treadle means for closing said door, and buier means yieldably opposing movement of said door to closed position near the end of its path of travel.
6. In an apparatus having a compartment open at one upright face, a door pivoted about a horizontal pivot for swinging movement upwardly to upright position in closing relation to the open face and downwardly to horizontal position for permitting access to the interior of the compartment, treadle means for opening thedoor, and buffer means yieldably opposing movement of the door rapidly along the final portion ci its path of travel toward open position and permitting substantially unopposed movement of the door more slowly to fully opened position. 7. In an apparatus having a compartment open at one upright face, a door pivoted about a horizontal pivot for swinging movement to upright position in closing relation to the open face and to horizontal position for permitting access to the interior of the open compartment, a spring urging the door to closed position, treadle means for closing said door, and buffer means opposing movement of said door to closed position near the end of its path of travel when the door is moved rapidly therealong toward such position and offering substantially no resistance to the door when the door is moved more slowly to said finalI position.
the door more slowly toward said "one of said positions, said buffer means comprising a cylinder member, a piston member reoiprocable therein,V one of said members being operatively connected to the door for movement thereby relative to the other member, and restricted passage means for permitting escape of air from one end of the piston member to the other during relative movement of the members.