US 3416513 A
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Description (OCR text may contain errors)
Dec. 17, 1968 FlSCHER ETAL 3,416,513
DEVICE FOR SECURING A HEATING PLATE To THE TOP PLATE OF A RANGE Filed Sept. 1, 1967 2 Sheets-Sheet 1 INVENTORS Kdf/ firz'z'er ATTORNEYS,
Dec. 17, 1968 K. FISCHER ETAL DEVICE FOR SECURING A HEATING PLATE TO THE TOP PLATE OF A RANGE 2 Sheets-Sheet 2 Filed Sept. 1, 1967 ATTORNEYS,
United States Patent Office Patented Dec. 17, 1968 E 32,48 9 Claims. (Cl. 126-215) ABSTRACT OF THE DISCLOSURE A device for securing a heating plate having an annular flange to the top plate of a range having a hole into which the flange is inserted by means of several spring clamps which are applied from the lower side of the range plate and each of which has one part resiliently pressing against the inner side of the range plate'and another part resiliently pressing in a downward direction against the flange, whereby an overflow or facing ring surrounding and secured to the upper end of the flange adjacent to the heating plate is pressed tightly upon the upper side of the range plate.
The present invention relates to a device for securing a flanged heating plate which is provided with an overflowor facing ring to the top plate of a range by resilient clamping means which are applied from below so as to engage upon the annular flange of the heating plate which is inserted into a hole in the range plate, and so as also to press against the lower side of this range plate, whereby the outer edge of the facing ring will be tightly pressed upon the upper side of the range plate.
For clamping a heating plate upon the area of the top plate of a range which surrounds the range hole, it is conventional to employ a bracket which bridges the range hole underneath the heating plate and through which a threaded bolt is passed which is secured to the heating plate, and to clamp the ends of this bracket against the lower side of the range plate by tightening a nut on the end of the bolt. In addition, this clamping bracket is usually prevented from turning by a pin which is secured to the heating plate. In order to prevent excessive stresses from being exerted upon the dilferent parts when the clamping nut is tightened, suitable spring means are inserted between the clamping bracket and the clamping nut or the clamping bracket itself is provided in the form of a spring.
Such securing means have the disadvantage that their production as well as their installation is rather expensive. Furthermore, since the clamping bracket is secured to the center of the heating plate, it interferes with the installation of a thermistor which should extend through a central aperture in this plate and engage with the bottom of a cooking vessel. In such a case it is necessary to secure the clamping bolt to the heating plate by special means which may, for example, bridge the central aperture.
It is an object of the present invention to secure a heating plate to the top plate of a range in a new and more inexpensive manner and by suitable clamping means which are applied to outer parts of the heating plate and leave its central part unoccupied. For attaining these objects the present invention provides these clamping means in the form of spring clamps or brackets which are applied on at least two points of the range plate adjacent to the upwardly drawn rim surrounding the hole in the range plate which is covered by the heating plate, and press with one side resiliently against the lower side of the range plate and with another side against the outside of the flange of the heating plate near the free lower end thereof.
These spring clamps or brackets may be made very inexpensively and of various designs and each of them may be stamped and bent of a single piece of sheet metal.
According to one embodiment of the invention, each of the spring clamps comprises a U-shaped part which is adapted to be'fitted from below upon the downwardly extending annular flange of the heating plate and has an extension on one of its arms which is bent outwardly and the end of which engages with a resilient pressure against the lower side of the range plate, while locking detents on the same arm engage into corresponding locking recesses or with locking projections on the flange of the heating plate.
In this embodiment of the invention it is advisable to provide the locking recesses for the spring clamps in thicker sections of the flange of the heating plate. The outer surface of each of these sections is either cylindrical or tapers slightly toward the free end of the flange and projects radially over the main outer surface of the flange. In this manner it is possible to provide the main part of the flange. with a thin wall, while the short thicker sections of the flange are provided with relatively deep and effective locking recesses. These sections on which the spring clamps are applied are made of such a thickness as to permit the locking recesses to be cut to a sufficient depth but without touching the main outer surface of the flange. These recesses may thus be easily cut into a relatively soft material, whereas thin walls of cast iron generally have very hard surfaces and are therefore hard to cut. The total weight of the heating plate is practically not increased by the thicker sections since they only extend over a fraction of the periphery of the flange.
The thicker sections of the flange of a heating plate of the type to which the invention relates, wherein this flange is pressed tightly into an overflow or facing ring which, in turn, is to be tightly pressed upon the upper side of the range plate around the range hole, are preferably designed so that, before the casting of the heating plate is machined, the outer surfaces of these sections are in alignment with and of the same diameter as the upper part of the flange upon which the facing ring is to be pressed so that, when the casing is turned on a lathe so as to cut this part to its accurate diameter for receiving the facing ring, these sections will be likewise cut to this diameter with the exception of the free end of each section which by remaining uncut then forms a radially projecting edge portion for supporting one of the spring clamps. Although these edge portions project radially over the part of the flange which serves as a seat for the facing ring, they do not prevent this ring from being passed over them so as to be pressed upon this seat since the inner wall of this ring will then elastically expand between the sections sufliciently so as to slide over these edge portions.
According to another embodiment of the invention, each of the spring clamps which are stamped and bent of sheet metal comprises a U-shaped part which is hooked over the upwardly drawn rim of the range plate surrounding the hole into which the flange is inserted. One side of this U-shaped part has at least one spring arm thereon which is bent outwardly so as to engage resiliently upon the inner side of the range plate and at least one further spring arm which is bent inwardly and at an oblique angle downwardly and presses resiliently against the outer side of the flange of the heating plate which is inserted from above into the range hole. This outer side of the flange may also be provided with a locking recess into which the last mentioned extension of each spring clamp may engage. When this embodiment of the invention is employed, the heating plate may be inserted in any desired rotary position into the range plate.
These and other features and advantages of the present invention will become further apparent from the following detailed description thereof which is to be read with reference to the accompanying drawings, in which- FIGURE 1 shows a radial section of a part of a heating plate and range plate and of one of the spring clamps which is applied from below over the flange of the heating plate;
FIGURE 2 shows a cross section which is taken along the line II-II of FIGURE 1;
FIGURE 3 shows a perspective view of one of the spring clamps;
FIGURE 4 shows a radial section of a part of an unmachined casting of a heating plate, the section being taken between two points on which the spring clamps are to be mounted;
FIGURE 5 shows a radial section similar to FIGURE 4, but taken at a part of the flange on which after being machined one of the spring clamps is to be mounted;
FIGURE 6 shows a radial section of a part of the finished heating plate between two points on which the spring clamps are to be mounted;
FIGURE 7 shows a radial section similar to FIGURE 6, but taken at a part of the finished flange on which one of the spring clamps is to be mounted;
FIGURE 8 shows a bottom view of a part of the finished heating plate;
FIGURE 9 shows a radial section similar t FIGURE 1 of a modification of the invention;
FIGURE 10 shows another radial section similar to FIGURE 1 of a further modification of the invention; while FIGURES 11 to 13 show perspective views of three different spring clamps according to the invention as may be applied, for example, in the embodiments according to FIGURES 9 and 10.
In the drawings, the heating plate is indicated at 1, its annular flange at 2, the range plate at 3, the upwardly drawn rim surrounding the hole for receiving the heating plate 1 at 4, a shoulder on range plate 4 which extends into the rim 4 at 5, the overflow or facing ring of the heating plate 1 which overlaps the rim 4 of the range plate at 6, and the spring clamps or brackets which clamp the heating plate 1 upon the range plate at 7.
The overflow or facing ring 6 of the heating plate 1 which surrounds the flange 2 and supports the heating plate on the shoulder of range plate 3 is formed in the conventional manner by a stamped sheet-metal part of an inverted trough-shaped cross section, the inner wall portion 6a of which is tightly pressed upon the flange 2 and against an outwardly projecting shoulder of the heaing plate itself. The upper part of the relatively thin flange 2 has a larger diameter and wall thickness than the lower part so as to form a seat 2a for the inner wall portion 6a of the facing ring 6.
In the embodiment of the invention so illustrated in FIGURES l to 8, flange 2 of heating plate 1 is reinforced on at least two, but preferably three points underneath the seat surface 2a by sections 2b which serve as points of connection for the spring clamps 7 and the upper outer surface of each of which is formed by the seat surface 2a, while underneath this surface the outer surface of each of these sections 2b projects radially over the adjacent outer surface 20 of the main part of flange 2. Near its free edge, each reinforced section 2b is provided with a recess 18 into which a part of the spring clamp 7 may engage in the manner as subsequently described.
Each spring clamp 7 is made of sheet metal and has a substantially U-shaped cross section with two arms 11 and 13. Arm 11 is provided on each end with an inwardly projecting prong 12 which is adapted to engage upon the inner side of flange 2, while the other arm 13 has an outwardly bent extension 14 with prongs 15 on its opposite ends which are adapted to engage upon the inner or lower side of shoulder 5 of range plate 3. This arm 13 of spring clamp 7 is further provided near both ends with detents 16 which are stamped out of the material of the clamp and are adapted to engage into the recess 18 in one of the reinforced sections 2b of flange 2.
Each spring clamp 7 is made of such dimensions that,
when fitted like a clip from below over one of the thicker sections 2b of flange 2 in the direction of the arrow 17, as shown in FIGURE 1, after this flange has been inserted into the range hole, the prongs 12 will press against the inner surface of flange 2, while the detents 16 will snap resiliently into the recess 18 after the prongs 15 are pressed resiliently against the inner side of shoulder '5 of range plate 3. The outwardly bent extension 14 of arm 13 is hereby elastically deformed which causes the spring clamp to be firmly supported by the prongs 15 on the inner side of range plate 3 and by the detents 16 in the recess 18 in one of the thicker sections 2b of flange 2. The heating plate 1 will thus be securely pressed down upon and locked to the range plate 3.
Before the raw casting of heating plate 1, as shown in FIGURES 4 and 5, is machined, the upper part of its flange 2 which is intended to serve as the seat 2a for the supporting ring 6 has a diameter D1 which is slightly arger than its final diameter D3, as shown in FIGURE 6, after it is machined. Before and after the casting of heating plate 1 is machined, the free edge of its flange 2 intermediate the thicker parts 2b has a diameter D2 which is smaller than the diameter D3 of the finished seat surface 2a. Before the casting is machined, the thicker parts 2b of flange 2 have the same outer diameter D1 and also substantially the same thickness as the upper flange part. When this upper part is turned on a lathe to the diameter D3 so as to form the seat surface 2a for the supporting ring 6, the thicker parts 2b are also turned with the exception of a noselike edge portion 20 on each of these parts which defines the recess 18 for receiving the detents 16 of one of the spring clamps 7. The outer surfaces of these lower edge portions 20 therefore remain uncut and retain their original outer diameter D1. The recesses 18 are cut to such a depth that the thinner parts 20 between the thick parts 2b will not be touched by the cutter which will therefore cut only into the thicker parts which are relatively soft any maybe easily machined.
In the modification of the invention as shown in FIG- URE 9, the facing ring 6 of the heating plate 1 rests on a conical surface of the range plate 3 which ascends at a relatively steep angle to the rim 4 of the range hole, while in the modification according to FIGURE 10, the supporting ring 6 rests on a shoulder 5 of the range plate.
The spring clamps 7 according to FIGURES 9 and 10 are fitted over the rim 4 of the range plate surrounding the range hole before the heating plate is inserted. These spring clamps 7 may be of different designs as shown, for example, in FIGURES 11 to 13. They have in C0111- mon that the strip of spring steel of which each of them is made comprises a U-shaped part 26 which is to be hooked over the rim 4 of the range hole, at least one spring arm 27 which engages with the lower side of the range plate, and at least one spring arm which projects into the range hole and is downwardly inclined and pressed like a barb against the flange 2 of the heating plate when the latter is applied from above. The heating plate 1 will thus be tightly clamped by the spring clamps 7.
In the embodiment according to FIGURE 9, in which the range plate has a conical surface extending to the rim 4 of the range hole, the end parts of this surface on which the spring clamps 7 are mounted are split so as to form tabs 30 which are bent upwardly and each of which has a width equal to the width of a spring clamp 7. The spring clamps 7 according to FIGURE 9 will in this manner be as firmly supported at those according to FIGURE 10.
The spring arm 27 of the spring clamp according to FIGURE 11 which is adapted to engage with the lower side of the range plate 3 is formed by a loop-shaped part on the end of one arm of the U-shaped part 26. The extension of this loop shaped part forms the spring arm 25 which is downwardy inclined and adapted to engage upon the flange 2 of heating plate 1.
The spring brackets according to FIGURES 12 and 13 are provided with three spring arms 25 and 27 which are formed by a pair of cuts in the extension of one arm of the U-shaped part 26 and by bending the two outer arms in one direction and the central arm in the opposite direction. Thus, according to FIGURE 12 the central arm forms the spring arm 27 which engages with the lower side of the range plate, while according to FIG- URE 13 the central arm forms the spring arm 25 which acts upon the flange 2 of heating plate 1.
As illustrated in FIGURES 9 and 10, respectively, the free end, of spring arm 25 of each spring bracket which is bent obliquely in the downward direction may either press resiliently against the outer side of flange 2 or it may engage into a locking recess 31 in flange 2.
Although our invention has been illustrated and described with reference to the preferred embodiments thereof, we wish to have it understood that it is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.
Having thus fully disclosed our invention, what we claim is:
1. A device for securing a heating plate having an annular flange projecting from one side thereof to the top plate of a range having an upwardly-drawn part and a hole in the upper end of said part for the insertion of said flange, comprising a facing ring surrounding and tightly secured to the upper part of said flange adjacent to said heating plate and adapted to overlap said upper end and to engage upon the outer side of said upwardlydrawn part to support said heating plate thereon, and a plurality of spring elements peripherally spaced from each other and each having one part resiliently pressing against the inner side of said upwardly-drawn part and another part resilient pressing against said flange near the lower end thereof so as to draw said heating plate downwardly and thereby to press said facing ring tightly upon said upwardly-drawn part of said range plate.
2. A device as defined in cairn 1, wherein each of said spring elements forms a spring clamp consisting of a single piece of sheet metal formed by stamping and bending.
3. A device as defined in claim 2, wherein said flange has at least one looking projection on the outer side of its free end, each of said spring clamps comprising a substantially U-shaped part having two arms adapted to be fitted from below over the free end of said flange, one of said arms having an extension bent outwardly and resiliently pressing against the lower side of said upwardly-drawn part of said range plate, said arm further having detents thereon adapted to engage resilienty into a recess defined by said locking projection on said flange.
4. A device as defined in claim 3, wherein said flan-ge has a plurality of reinforced sections in accordance with the number of said spring elements and peripherally spaced from each other, each of said sections having a substantially cylindrical outer surface and a radial projection near its free end forming said locking projection.
5. A device as defined in claim 4, wherein said heating plate is made of a casting, the upper part of the flange of said casting having a considerably larger outer diameter than its lower part, each of said reinforced sections of said casting having substantialy the same outer diameter as said upper part, said upper part together with said sections then being turned to a smaller diameter but larger than said lower flange part with the execption of an end portion of each of said sections which remains uncut and thus retains its original casting surface, said turned upper part of said flange serving as a seat for said facing ring and said uncut end portion of each of said sections forming said radial locking projection.
6. A device as defined in claim 2, wherein each of said spring clamps comprises a substantially U-shaped part adapted to be hooked in an inverted position over the upper end of said upwardly-drawn part of said range plate surrounding said hole, at least one first spring arm bent in one direction relative to said U-shaped part and adapted to press resilienty against the inner side of said upwardly-drawn part of said range plate, and at least one second spring arm bent in the opposite directionrelative to said U-shaped part so as to extend downwardly at an oblique angle and adapted to press like a barb against the outer side of said flange near its lower end.
7. A device as defined in claim 6, wherein said flange has at least one locking projection on the outer side of its free end, said second spring arm being adapted to engage resiliently into a recess defined by said locking projection.
8. A device as defined in claim 6, wherein said first and second spring arms are formed by an extension of one arm of said U-shaped part, said extension being bent to a loop shape forming said first arm adapted to press resiliently against the inner side of said upwardly-drawn part of said range plate, the free end portion of said extension beyond said loop-shaped part forming said second spring arm.
9. A device as defined in claim 6, wherein said first and second spring arms are formed by an extension of one arm of said U-shaped part, said extension being split in its longitudinal direction so as to form separate tabs which are bent in opposite directions so as to form said spring arms.
References Cited UNITED STATES PATENTS 1,922,420 8/1933 Coulston 126-215 2,664,492 12/1953 Fischer 1262l1 CHARLES I. MYHRE, Primary Examiner.
E. G. FAVORS, Assistant Examiner.