US 3176488 A
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Description (OCR text may contain errors)
E. N. JACOBI 3,176,488
TUMBLER SPRING RETAINER FOR PIN TUMBLER CYLINDER LOCK April 6, 1965 2 Sheets-Sheet 1 Filed Feb. 6. 1963 JmJpwf L .MM W. d
A ril 6, 1965 E. N. JACOB] 3,176,488
TUMBLER SPRING RETAINER FOR PIN TUMBLER CYLINDER LOCK Filed Feb. 6, 1963 2 Sheets-Sheet 2 United States Patent ice iwws Patented Apr. 6, 1965 l. 2 3 176 483 general objectof the present invention toprovidea tumi bler spring retainer for a pin tumbler cylinder lock, which PIN retainer can be. formed as asimple stamping and is. ca.-
Edward N. Jacobi, Milwaukee, Wis, assignor to Briggs &
Stratton Corporation, Milwaukee, Wis., a corporation This invention relates generally to cylinder locks of the pin tumbler type, and'more specifically concerns a tumbler spring retainer or cover for such a lock.
In pin tumbler cylinder locks the tubular casing in which the cylinder of the lock is rotatably housed is usually made as a die casting having an integral, ridge-like, radially projecting tumbler chamber xtending along one side thereof. Through the tumbler chamber portion of the casing there are a number of parallel tumbler bores, radial to the casing axis and spaced along its length, which open at their opposite ends to the cylinder bore in th casing and to the radially outwardly facing surface of the tumbler chamber. A pin tumbler is slidable in the inner portion of each of the tumbler bores, and a coiled compression spring, housed in the outer portion of each tumbler bore, biases the tumbler radially inwardly. The outward reactions of the several tumbler springs are received by a substantially channel-shaped cover or tumbler spring retainer which straddles the ridge-lik tumbler chamber with its legs or flanges overlying the opposite circumferentially facing sides thereof and with its web portion flatwise overlying the radially outer surface of the tumbler chamber and covering the mouths of the tumbler bores.
It has heretofore been conventional to make the tumbler spring retainer as a thin metal stamping, and to form the die cast casing with a pair of narrow radially outwardly opening grooves, one along each side of the tumbler chamber ridge, in which the longitudinal edge portions of the flanges of the retainer were received when the retainer Was assembled onto the casing. The retainer was secured in place on the tumbler chamber by staking metal from the casing die casting into the grooves just mentioned, over suitable abutments formed on the leg or flange portions of the cover. The usual practice in fastening the retainer to the casing was to hold the retainer in place on the tumbler chamber while four punches, operating simultaneously, struck metal from the edge portions of the grooves in the casing die casting inwardly over the flanges of the retainer.
The practice of securing the cover or retainer in place by staking had several disadvantages which made it objectionable both from the standpoint of production expediency and from the standpoint of the quality of the finished lock. It was essential to have the four staking punches penetrate into the metal of the casing die casting by a very closely held distance. If any one of the staking punches did not penetrate far enough into the metal, it would not stake over enough metal to provide proper anchoring of the retainer. If any one of the punches penetrated too far, it tended to chip ofi the part of the metal that it was engaging. Proper staking action of each punchdepended upon accurate adjustment of the punch press ram, upon the accuracy and sharpness of the staking punches, and upon uniformity of diameter of the casing die castings being staked, and since there were four punches, there were four chances forimperfect staking on each lock assembly.
But even when the staking operation was accomplished successfully, it was troublesome to make repairs on a lock having its tumbler spring retainer thus secured by stakings because of the difiiculty of removing the retainer to gain access to the tumblers and their springs and the necessity for restaking the retainer when the lock was reassembled.
With the foregoing considerations in mind, it is the pableoi being securely fastened in. place on the tumbler chamber of a lock casing by its mere assembly onto the casing, without the need. for any staking or. similar fastoningv operation.
It is thus another general object of this. invention to provide means, ina pin tumbler cylinder lock,.for securinga tumbler spring retainer on the casing of the. lockwithout necessity for astaking or other fastening operation.
during assembly of the. lock, to thus simplify andexpedite the assembly of such locks andtherebyreduce their cost without, however, in any wise comprising. their quality.
It is also an object of this invention to provide asnap action securement means ona pintumblercylinder look by which a tumbler spring retainer is fastened to the lock casing in such amanner that the retainer is readily removable from the casing without likelihood of damage thereto, to permit repairs to be made to the lock, and is easily replaceable on the casing without special tools.
Another and more specific object of this invention is to provide securement means for fastening. the channelshaped tumbler springtretai'ner of a lock of the character described to the ridge-like tumblerchamber on the lock casing, which securement means comprises a pair of integral ledges on the tumbler chamber, one at each side thereof near its radially outer face, each facing radially inwardly relative to the casing, and integral spring tangs on the legs or flanges of the retainer that snapunder the ledges when the retainer is assembled onto the tumbler chamber to ,thussecure the retainer to the casing.
With the above and other objects inview which willappear as the description proceeds, this invention resides in the novel construction, combinaton and arrangement.
of parts substantially as hereinafter describedand more particularly defined by the appeeded claims, it being.
understood that such changes in the precise embodiment of the hereindisclosed invention may be made ascome within the scope of-the claims.
The accompanying drawings illustrate one completeing the principles of this, invention, the retainer being,
shown in disassembled relation to the casing;
FIGURE 2 is a side view of the casing with the retainer in place thereon; and
FIGURE 3 is a view partly in rear elevation and partly in cross section of the casing with the retainer inplace thereon.
Referring, now more particularly to the accompanying.
drawings, the numeral 5 designates generally the tubular casing of a pin tumbler cylinder lock, having anaxial. V bore 6 inlwhicha cylinder 7 is rotatable, and formed with an integral ridge-like tumbler chamber 8"that extends lengthwise along the exterior of the casingatone side thereof. The casing, which is preferably made as a i die casting, has a number of parallel, small diameter tumbler bores 10 through its tumbler chamber, locatedat spaced intervals along the casing axis andextending.
radially thereto, with their inner ends opening to the cylinderbore .6 in the casing" and their outer ends opening through the radially outer surface 11 of the ridge 8 that provides the tumbler chamber.
A pin tumbler 12 is slidable in each of the tumbler.
bores 1t? and is biased radially inwardly by a coiled compression spring 13 which is housed in the outer portion of the tumbler bore. A generally-channel-shaped cover or tumbler spring retainer 14 of this invention closes the tumbler bores at their outer ends to confine the several tumbler springs 13 in their respective bores and receive their outward reactions.
The retainer 14 is preferably formed as a one piece stamping of relatively thin, resiliently flexible metal having an elongated substantially rectangular web or body portion 16 which flatwise overlies the radially outer sur face 11 of the tumbler spring chamber, and leg or flange portions 17 which are bent from opposite longitudinal sides of the web portion and which both extend in the samerdirection therefrom to overlie the opposite circumferentially facing side faces 18 of the tumbler chamber.
Each flange portion of the cover has a substantially wide outwardly opening notch 19 therein, intermediate its ends, by which it is divided into two lengthwise spaced apart legs 20, each capable of substantial flexing independently of the other. Each of the legs 20'has a U- shaped .cut 21 therein that defines an integral tang 22 which is connected with the leg near the free outer edge of the latter and which projects obliquely inwardly, toward the web portion of the retainer and toward the leg opposite that from which the tang is struck.
The retainer is secured in place on the tumbler spring chamber by the engagement of the free edges of the tangs V 22 under integral ledges 23 on the casing which project in opposite circumferential directions from the tumbler chamber near its-radially outer surface, and which define lengthwise extending abutment surfaces 24 on the chamber that are radially spaced from the cylindrical external surface of the casing and face inwardly toward the same. Those skilled in the art will recognize that the abutment surfaces 24 can be formed on the casing by die casting mold members that are drawn off in the axial direction of the casing, along with the core that forms the cylinder bore 6, so that the provision of the ledges 23 on the casing does not substantially increase the cost of die casting it.
To prevent lengthwise displacement of the retainer 01f of the casing, the tumbler chamber is preferably formed with small lug-like shoulders 25 near its ends, adjacent to its radially outer surface 11, projecting circumferentially beyond the ledges 23 and defining axially facing abutments that oppose one another and are engaged by the end edges of the flange portions 17 of the retainer.
It will be apparent that the shoulders 25 can be formed by die casting mold members which extend along 'most of the length of that portion of the mold cavity that de fines the tumbler chamber, and which can be withdrawn radially relative to the casing along with the cores that define the tumbler bores.
It will be evident that the retainer can be assembled onto the tumbler chamber by moving the retainer in the directionaflatwise of its web portion, with a substantially translatory motion, until the tangs 22 snap inwardly toward one another and engage under the ledges 23 as the web portion 16 of the cover comes into fiatwise engage-- ment with the radially outer surface 11 of the tumbler chamber. To facilitate such assembly, the free outer end portions of the legs can be bent obliquely outwardly, as at 27, so that the legs tend to be cammed outwardly by the ledges as they pass over the latter. The oblique inclination of the tangs 22, of course, also enables them to be cammingly flexed outwardly by the ledges as the cover is installed on the tumbler chamber. Although the tangs are relatively short, they are nevertheless capable of a substantial amount of resilient flexing motion because they are in effect arranged in tandem with the,
U-shaped leg portions that surround them and which are also capable of resilient flexing It will be apparent that the cover of this invention can be readily removed from the casing by prying its legs apart with a screwdriver or the like, to disengage the tangs from under the ledges 23. Insertion of a screwdriver under each leg is facilitated by the outwardly bent free edge portions 27 on the legs.
From the foregoing description taken together with the accompanying drawings it will be apparent that this invention provides a tumbler spring retainer for a cylinder lock of the character described which comprises a simple stamping that is secured to the ridge-like tumblerchamher one lock casing by the mere act of assembling it thereto; and it will be further apparent that the snap action tumbler spring retainer securement means of this invention reduces the cost of producing a lock which incorporates it and facilitates repair of such a lock, without in any wise compromising the quality of the look.
What is claimed as my invention is:
1. In a lock of the type having a tubular casing with a ridge-like tumbler chamber extending lengthwise along one side thereof that has a radially facing outer surface and opposite circumferentially facing side surfaces, and which casing has parallel, axially spaced radial tumbler bores that open to said outer surface of the tumbler chamber, in each of which there is a tumbler and a coiled compression spring that biases the tumbler radially inwardly, means for holding the tumblers and springs in said bores and for receiving the outward reaction forces of the springs, said means comprising:
(A) means on the casing providing a pair .of ledges,
one extending along each side of the tumbler chamber near its outer surface and each having a radially inwardly facing surface that extends circumferentially beyond its adjacent side surface of the tumbler chamber; and
(B) a resiliently flexible unitary retainer that straddles the tumbler chamber, said retainer having (1) an elongated body portion which flatwise overlies the outer surface of the tumbler chamber,
(2) integral leg portions bent from opposite sides of the body portion and which overlie the side surfaces of the tumbler chamber, and
(3) an integral tang on each of the leg portions, defined by a U-shaped slit in the leg portion that has its bight portion adjacent to the body portion of the retainer, each of said tangs being bent out of its leg portion to project obliquely inwardly and toward the body portion from near the outer free end of its leg portion and to be engaged under one of said ledges, said tangs on opposite sides of the retainer being flexible away from one another to permit installation of 2. As an article of manufacture, a unitary tumbler retainer for a lock of the type having a tubular casing along one side of which there extends a ridge-like tumbler chamber that has a radially facing outer surface, opposite circumferentially facing side surfaces, and parallel, axially spaced, radial tumbler bores that open to said outer surface of the tumbler chamber, in each of which bores there is a tumbler and a coiled compression spring that biases the tumbler radially inwardly, said tumbler retainer being made of resiliently flexible material and comprismg:
(A) an elongated substantially'flat body portion;
(B) integral legs on the body portion, projecting in one direction from its opposite longitudinal side edges; and
(C) integral tangs on said legs, each definedby a substantially U-shaped slit in the leg that has its bight portion near the body portion, each tang being bent out of the plane of its leg near the free outer end of the latter to project obliquely inwardly toward the opposite leg and the body portion, said tangs being engageable under radially inwardly facing ledges along the opposite sides of the tumbler chamber of a casing on which the retainer is installed to hold the retainer in place on the tumbler chamber with its body portion flatwise overlying the outer surface thereof and covering the mouths of the tumbler bores and with its legs overlying the opposite side surfaces of the tumbler chamber, said tangs being flexible away from one another to enable assembly of the retainer onto the tumbler chamber by substantially translatory motion of the retainer radially inwardly relative to the casing.
3. In a lock of the type comprising a tubular casing having a ridge-like tumbler chamber extending along one side thereof and having a plurality of parallel, radially extending, axially spaced tumbler bores, each opening through a radially facing outer surface on said tumbler chamber, a tumbler in each tumbler bore, a spring for each tumbler by which the same is biased inwardly in its bore, and a substantially channel-shaped tumbler spring retainer, means for holding the retainer in place on the tumbler chamber, straddling the same, with the flange portions of the retainer overlying circumferentially facing side surfaces on the tumbler chamber and its web portion overlying said outer surface to confine the tumblers and tumbler springs in their bores and receive the reactions of the tumbler springs, said last named means comprising:
(A) means on the casing defining a pair of ledges, one extending along each side of the tumbler chamber near its outer surface and each providing a radially inwardly facing surface that projects circumferentially beyond its adjacent side surface of the tumbler chamber; and (B) a resiliently flexible tang projecting from each flange of the channel-shaped retainer, near the outer free edge thereof, each of said tangs being defined by a substantially U-shaped slit in its fiange that has its legs extending toward the free edge of the flange, and each of said tangs being bent inwardly out of the plane of its flange to project obliquely inwardly toward the other and toward the web portion of the retainer, said tangs being engaged under said ledges and by their flexibility enabling the retainer to be assembled onto the casing by translatory motion of the retainer radially relative to the casing. 4. The tumbler retainer defined by claim 2 wherein there are a pair of legs projecting from each longitudinal side edge of the body portion, which legs are spaced from' one another along the length of the body portion; and wherein said legs and their tangs are arranged in laterally opposite pairs to cooperate with one another in preventing twisting of the body portion when the retainer is in place on a tumbler chamber.
References Cited in the file of this patent UNITED STATES PATENTS 1,487,307 Best Mar. 18, 1924 1,707,643 Segal Apr. 2, 1929 2,877,638 Muttart Mar. 17, 1959