US 2797591 A
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Description (OCR text may contain errors)
July 2, 1957 M. w. MARRAPl-: 2,797,591 v APPLIANCE xNoBs f Filed July 1953 Igp. s. 'A 17332422 20 1731 I8 Il I 1y lel f 6 8 4' 'q Y J'll 7 our@ 4% g )fm AITURNEKS APBLIANCE "KNOBAS Marius W. Marrapese, ledford, Ghio, assignor to 1`he Patent Button Company of Tennessee, Inc., Knoxville, Tenn., a corporation of Tennessee Application July, 21953Serial No. 366,140
8 laims. (Cl. 74-528) This application is a continuation-inpart of my prior application'for Appliance'lnobs, filed September 3, 1952, Serial No. 307,617.
This invention relates to improvements in appliance knobs, and more particularly to the control knobs for gas and electric stoves and other appliances. Itis well known that young children tend to turn on electric and lgas appliances, which often create real hazards and sometimes serious .injury. Various attempts have been proposed heretofore to provide knobs which will prevent accidental operation of such appliances, or manipulation thereof by small children, but these have depended on threaded connections between the parts, orwother objectionable characteristics thereof, which have not been satisfactory for efficient manufacture and use.
A valve knob generally requires lat least one indication point to show the dierent set positions of the valve or other 'control for the appliance, as the Off position. In some instances, additional legends are desirable thereon, as"O`n, Broih Simmen etc. Such markings must necessarily rotate with the turning of rthe valve stem or control for the appliance.
ln my prior application, such legends were applied to the surrounding rim of the back plate, which required an outward projection thereof beyond the rotatable knob. yIt has been found that such a projection leaves that portion exposed to the possibility of its being gripped for turning the valve or appliance control, whereby that particular construction may not be considered as completely foolproof as is desired.
One object of this invention is to overcome the objections heretofore encountered in prior constructions, including the form of knob set forth in my above-mentioned application, and to improve the construction thereof for controlling various appliances.
Another object of the invention is to provide a surface which is fixed to the appliance control member upon which an indication may be applied and which cannot be grasped for turning of the appliance control except by manipulation of the control knob.
These objects may be accomplished, according to one embodiment of the invention, by confining the back plate of the center post within the outer periphery of the shell of the control knob so as not to leave it exposed for grasping by children or anyone else who may try to turn the appliance control, without the necessity for manipulation and engagement of the control knob. The center post is adapted to be xed to the appliance control unit, such as the valve stem of a gas appliance. A disk is xed to the center post to rotate therewith upon turning of the post, and carries the indicia that indicates the rotated position of the appliance conrol, such as the valve stern. This disk is confined within an axially projecting portion of the outer shell of the control knob, so that it cannot be grasped by a child, for instance, for rotating the control member. Thus, a completely foolproof appliance Patented July 2, 1957 ice knob is provided ,withoutprojectingparts of :the appliance control forrotating thelatter withoutmanipulationtofthe control knobnto'itsengaged position. Thelatter normally is `disengaged by spring means and has suitable clutch meansfor ,engagementfthereoi as set forth morein detailin my above-mentioned application.
One embodiment-of Vthis invention isillustrated in the Laccompanying drawings, in which:
Fig. `l is a Iperspective view of the appliance knob detached;
IFig. 2 is a perspective view of the center post and back Plate;
Fig. 3 is a cross section through the appliance knob, with the control knobinits disengaged position.
4 is a similarview showing the control knob engaged; and
Fig. 5 is a detail plan view of the center portion of the appliance knob with parts removed.
This appliance knob maybe used for controlling Vthe valve of a gas stove or the electric switch of an electric stove, or other electric lappliance that will prevent operation of the valve or switch by young children, or accidental or unintended operation thereof by bodily contact with the Valve orswitch. I have designated a portion ofthe appliance control, either a valve stem or an electric switch shaft, generally by the numeral l, and it will be understood that this is intended merely as an example of thecontrol-,means for the appliance to which the invention may be applied.
The appliance knob includes a center port generally designated at 2,' which is tubular and has a suitable provision for connection with the shaft 1, such as a split D-shaftthat will provide a press-tit or other connection between the post 2 land the shaft 1 or other .control means. The post 2 ,is `partially lClosed at its upper end by an inturned flange 3, provided with a central hole 4 therein, as shown in'Figs. 2 and 3. The holed, through the closed end portion 3 .of the center post, may be provided with a rcounterbore 5,;as shown, to receive the head of a fastening that extends through the central hole 4, as hereinafter described.
At its lowerend,.the center post 2 is provided with a back plate 6, which projects outwardly therefrom in a radial direction, and preferably is formed in one integral piece with the center post Z.
Acontrol knob is provided on the post 2 and comprises an outer shell generally indicated at 7, which is somewhat cylindrical in form but may have peripheral ribs 8 thereon to facilitate grasping of the shell, or other suitable means that will provide a friction surface thereon to facilitate rotation of the control knob by hand. The outer shell 7 is shown as having a depending skirt portion at its lower edge, as indicated at 9, that extends to the lower face of the back plate 6, and encloses the latter completely, thus confining the back plate at its periphery againset accidental grasping by a child who might try to turn the appliance control thereby.
The control knob has a hub lll vofcylindrical form surrounding the post 2 and journaled thereon for rotation and' axial sliding movement relative thereto. The hub 10 is spaced radiallyrfrom the outer shell 7 and is connected therewith by a radially extending rib 11 that extends circumferentially around the hub vl() therebetween. The` web llis o frset axially of the outer shell 7 with a portion of the web spaced from thehub 1t) to provide a circumferential channel 12 therearound, forming a lspring seat in the underside of the control knob.
Provision is made for clutchv connection between 4the control knob 7,-11 and `the hub. 2 upon axial Yshifting of the control` knob relative Athereto to engage the clutch mepans,.-while.permitting free turning movement of the control knob relative to the center post upon disengagement of the clutch means. Several forms of clutch engagement means are shown in my application referred to above, any of which may be used, as desired, for this purpose. However, I have illustrated in this embodiment a clutch connection provided with interengaged teeth 13 and 14 formed, respectively, on the outer edge portion of the back plate 6 and on the otfset portion of the web 11 just inside the outer shell 7. These teeth are formed in respective rows, spaced apart circumferentially in each row, and so disposed as to interengage with each other 'to form a positive jaw clutch upon inward movement of the control knob relative to the post 2.
Yieldable means should be provided for normally maintaining the control knob in its outer position with the clutch means disengaged, except when it is desired to positively turn the appliance control. I have shown a coiled compression spring interposed between the back plate 6 and the web 11, surrounding the hub 10 and seated within the recess 12 of the control knob. This spring 15 normally will disengage the clutch teeth 13-14 when the control knob is released, and yet will permit engagement thereof uponaxial shifting of the control knob relative to the center post 2.
The outer end portions of the center post 2 and hub 10 are overlapped by a Washer 16 which is seated upon the outer end of the post 2 and centered by projecting `pins 17 on the post, preferably formed integral therewith, The washer 16 thus 30 as illustrated in this embodiment. limits the outward sliding movement of the control knob 7-11 axially along the center post 2 under the influence of the spring 15. v
The washer 16 is retained inplace by a central disk, generally indicated at 18. The disk 18 extends over the outer face of the center post 2 and the control knob throughout the major portion of the area thereof with an `inturned peripheral flange 19 that is spaced from the surrounding wall formed by the outer shell 7, so as to allow freedom of rotary andaxial movement of the control knob relative to the central disk 18, and yet closing the outer end of the control knob by said central disk. The central disk 18 has a corrugation 20 formed ltherein at the outer end of the post 2, providing an edge portion 21 that bears upon the periphery of the washer 16 to reduce the area of contact therewith, and yet to vconfine the washer in place on the post 2. The central disk 18 also has inturned ears 22 on opposite sides of its center, beside the axially projecting pins 17 on the post 2 to center the disk 18 with respect thereto.
The central disk 18 is confined by a rivet or other fsuitable fastening, generally indicated at 23, having a head 24 overlying the outer face of the central disk 18 at the center thereof, while a head 25 on the rivet 23 engages the countersunk portion 5 of the centerbore of the post 2 to confine the parts in secure relation thereto without the use of screw means.
Provision is made for holding the central disk 18 against rotation relative to the center post 2 and to cause it to rotate therewith. In this embodiment of the invention, the washer 16 is provided with an elongated slot l28, as shown in Fig. 5, through the opposite ends of which the pins 17 project. The ears 22 on the central Vdisk 18 are also turned downinto the opposite ends of nthe slotr28 beside the pins 17, while the center of this slot 28 is enlarged to accommodate the rivet-23. The projecting pin .17 and ears 22 act as keys to the washer 16, while the latter connects the central disk 18 with the center post 2 through these key connections, thereby eliminating any independent turning of the washer `16 on the central disk 18vwith respect to the center post 2; The central disk 18 also serves to carry suitable indicia thereon, as generally indicated at 26,tbeing illustrated by 'the word fOff. Any other suitable indicia maybe used Cthereon such, for instance, as On, Broil, Simmer,n
nknob and post engageable upon rearward movement of 1f" without manipulating the control knob, which normally is disengaged by the spring 15, thus providing an effective foolproof control. As noted above, the disk which carries the indicia or legend is recessed within the free r rotatable outer shell and confined entirely by the sur- 0 rounding wall thereof, when the control knob is in its outermost position, which prevents grasping of this disk by hand.
The center post and control knob may be molded of plastic or otherwise constructed of suitable material.
This construction also eliminates the requirement of lappliance knobs proposed heretofore which used threaded connections between the parts. Thus, a practical unitary Ystructure is provided, with the part fully enclosed and r.without danger of disconnection as a result of such threaded connections, as were required therein. An ef vfective appliance control which is completely foolproof is thus provided.
While the invention has been illustrated and described in one embodiment, it is recognized that variations and 'changes may be made therein without departing from `the invention as set forth in the claims.
l. An appliance knob comprising a center post adapted A to be connected with an appliance control member, a control knob mounted on the center post for rotary and 'axial movement relative thereto, clutch means between the knob and post engageable upon rearward movement of said knob and a disk carried by the center post and fixed 40 thereto and substantially covering but received in the front the knob and post engageable upon rearward movement of said knob and a disk carried by the center post and fixed thereto and substantially covering the outer portion of the knob, means yieldably urging control knob outwardly relnative to the center post, said control knob having an outer 'rim portion surrounding the disk. 3. An appliance knob comprising a center post adapted to be connected with an appliance control member, a control knob mounted on the center post for rotary and axial movement relative thereto, clutch means between the said knob and a disk carried by the center post and fixed thereto and substantially covering the front of the knob, and means yieldably urging the control knob to an outer position relative to the center post, said control knob having an outer rim portion therein with the periphery of the disk inwardly of the outer edge of said rim portion in said outer position.
4. An appliance knob comprising a center post adapted to receive therein an appliance control member, a control knob mounted on the center post for rotary and axial movement relative thereto, said knob having an outer recess providing an internal hub wall portion and a spaced Y external rim wall portion, means yieldably urging the control knob outwardly relative to the center post, a member carried by the center post and fixed thereto, overlapping and providing a lstop for the hub wall portion, and a disk I overlapping the center post and extending between the rim portion of the knob and the member.
5. An appliance knob comprising a center post adapted to be connected with an appliance control member, a control knob mounted on the center post for rotary and axial movement relative thereto, clutch means between the knob and post engalgeable upon rearward movement of said knob, said control knob having a hub portion journaled on the center post and having an annular recess therein surrounding the hub portion, and a coiled spring surrounding the center post and having one en'd seated in said recess, saitl control knob having an outer shell spaced from the hub portion with a radial web therebetween having the annular recess formed in said web.
6. An appliance knob comprising a center post a'dapted to be connected with an appliance control member, a control knob mounted on the center post for rotary and axial movement relative thereto, means forming a clutch connection ltherebetween the control knob and the center post for engagement upon axial movement of the control knob in one direction relative thereto, a central disk covering the outer end portion of the control knob and having indicia thereon to represent a position of the center post, and means `forming a key connection between the center post and the central disk locking these parts together.
7. An appliance knob comprising a center post adapted to be connected with an appliance control member, a control knob mounted on the center post for rotary and axial movement relative thereto, meansv forming a clutch connection between the control knob and the lcenter post for engagement upon axial movement of the control knob in one direction relative thereto, a central disk covering the outer end portion of the control knob and having indicia thereon to represent a position of the center post, a washer overlapping adjacent portions of the control knob and center post and having an elongated slot therein, key means iixed to the center post and projecting into the slot, said central disk overlapping the washer, and key means connected with the central ydisk and projecting into the slot beside the first-mentioned key means and cooperating therewith to form a locked vconnection between the central disk and the center post for maintaining these parts in secure relation to each other.
8. An appliance knob comprising a center post adapted to be connected with an appliance control member, a control knob mounted on the center post for rotary and axial movement relative thereto, clutch means between the knob and post engageable upon rearward movement of said knob, a disk carried by the center post and fixed thereto and substantially covering, but received in, the front of the knob, said -post having a back plate at the rear end thereof, said knob having a rearwardly projecting rim at the rear end thereof enclosing the adjacent periphery of the back plate.
References Cited in the file of this patent UNITED STATES PATENTS 409,100 Hall Aug. 13, 1889 600,849 Brown .Man 15, 1898 893,184 Mercer July 14, 1908 1,100,286 Cornelius June 16, 1914 1,113,613 Goozey Oct. 13, 1914 1,527,617 Tuska Feb. 24, 1925 1,575,410 Bradley Mar. 2, 1926 2,262,667 Datorn et al Nov. 11, 1941 2,427,310 Shumaker Sept. 9, 1947 2,501,008 Schramm Mar. 21, 1950 2,602,351 Ringler et al. July 8, 1952 2,660,904 Hilsinger Dec. 1, 1953 FOREIGN PATENTS 14,680 Great Britain July 17, 1899