US3257908A - Key cutter clamp hold down - Google Patents

Description

June 28, 1966 w, HAGGSTROM 3,257,908

KEY CUTTER CLAMP HOLD DOWN Filed Sept. 25, 1964 2 Sheets-Sheet 1 F/ G- 2 INVENTOR ATTORNEY June 1966 w. RQG. HAGGSTROM 3,257,903

KEY CUTTER CLAMP HOLD DOWN Filed Sept. 25, 1964 2 Sheets-Sheet 2 INVENTOR F G 6 J muraema/maasmoM,

774 any K34 ATTORNEY United States Patent 3,257,908 KEY CUTTER CLAMP HOLD DOWN Walter R. G. Haggstrom, Westminster, Mass., assignor to Independent Lock Company, Fitchburg, Mass, at corporation of Massachusetts Filed Sept. 25, 1964, Ser. No. 399,209 Claims. (Cl. 90-1305) This invention relates'to a key cutter device or the like, and particularly to an improved key clamp assembly therefor.

More particularly, this invention relates to a key holding clamp for a key cutter or the like of the type shown in United States Patent No. 3,138,999, the clamp serving to secure a key and key blank in fixed position during the cutting and pattern tracing operations.

Still more particularly, this invention relates to a key clamp of the type in which a key is pressed into a predetermined position by hold down means engaging the upper edge of the blade of the key, thus to dispose the key in a desired orientation, the clamp including jaw means for clamping the key in the desired position and mechanism for clearing the hold down member from the key after clamping has been effected.

Still more particularly, this invention relates to an improved key clamp of the type described wherein the insertion and positioning of the key in the key clamp is greatly facilitated.

In the aforesaid United States patent there is described an automatic key cutting device wherein there are provided a pair of key clamps for holding the key and key blank, respectively, during the processing thereof. As will be readily understood by the skilled worker, in a manually operated key cutting device, a key and key blank are placed in predetermined position in individual vises which are tightened to secure the same in the desired position while the pattern key is traced and the key blank is cut to conform to the pattern key.

The above noted patent teaches, inter alia, automatic mechanism for securing the key and key blank in the desired position. While the locating and securing apparatus of the aforesaid patent has proven reliable and efiicient, it has been determined that a more positive and facile preliminary location of the key and key blank in the clamps is desirable, particularly where the operation of inserting the key and th blank into the cutting machine is to be carried out by a person unschooled in the art of locksmithing.

It is a particular advantage of the present invention that the insertion of the key and key blank into the clamps is rendered easy and foolproof to the extent that the automatic key cutter embodying the novel clamp device may be utilized, for instance, in the automatic vending of key blanks, the purchaser being required merely to slide the key to be duplicated and the blank to be cut axially into the appropriate clamps.

It is, accordingly, an object of the invention to provide an improved key clamp.

Still a further object of the invention is to provide an improved held down device for a key clamp of the type described.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, reference is made to the accompanying drawings, forming a part hereof, in which Patented June 28, 1966 FIGURE 1 is a perspective view of a key clamp hold down operating structure such as may be embodied in a key cutting machine or the like, with parts of the key gripping structure eliminated for purposes of clarity;

FIGURE 2 is a vertical section through the clamping assembly in accordance with FIGURE 1, illustrating cer-v tain of the clamp portions;

FIGURE 3 is a plan view of the clamping assembly shown in FIGURE 2;

FIGURES 4 and 5 are sectional views taken on the line 4-4 of FIGURE 3, showing the position of the parts, respectively in the initial entering and fully seated positions of a key in the key receiver slot;

FIGURE 6 is a section through a key clamp showing the position of the parts after the hold down means has been cleared from a position above the key.

In acordance with the invention and as more fully set forth in Patent No. 3,138,999, there is shown in FIG- URE 1 key receiver slots 20, 21 mounted on a portion of the frame of an automatic key cutting machine, such as illustrated in said patent.

The clamping mechanism, as best seen in FIGURE 2, incorporates shiftable jaw portions 22, 23 which are initially spaced a predetermined distance from retainer shoulders 24, 25, respectively, the said jaws being shiftable toward and away from the shoulders by clamp mechanism 26, 27, the operation of which is not germane to the present invention. The clamp jaws 22, 23 serve to secure the key and key blank in their desired position during the tracing and cutting operations.

Initially it is necessary precisely to locate the key and key blank in the key slots 20, 21, and for this purpose there are provided hold down members 30, 31, which are initially disposed above and in spaced relation to horizontal base or anvil portions 32, 33, respectively, of the slots 21 and 20. The hold down members 30, 31 are normally urged in a counterclockwise direction as viewed in FIGURE 2, respectively by' the coil springs 34, 35. When a key and key blank are inserted into the slots with the base portions resting against the anvils 32, 33, respectively, the hold down members 39, 31 are cammed or raised by engagement with the key and are thus shifted in aclockwise direction, the biasing force or torque exerted by springs 34, 35, maintaining the parts in the desired position. Subsequently, with activation of the machine, the clamp jaws 22, 23 clamp the keys as previously described and, in timed sequence, the hold down members 30, 31 are pivoted to a position clear of the key and key blank to permit access to the upper surface of the blade portions of the key and blank.

The mechanism by which the foregoing operations are effected is fully disclosed in the aforesaid patent and will not be repeated herein, the present invent-ion being directed merely to improved hold down members for facilitating the insertion and positioning of the key and key blank.

The hold down mechanisms 30, 31 are identical and, hence, a description of one will suffice for an understanding of the invention.

To the pivotally mounted hold down lever 40 of the hold down member 31, there is mounted a pawl member 41. The hold down lever includes an extending block 42, terminating in a substantially planar under surface 43.

The pawl 41 is pivotally mounted in a recessed portion 44 formed on the hold down lever 40, on a pivot pin 45 mounted in an aperture 46 formed in the hold down lever, the pin extending through a corresponding registering aperture 47 formed in the pawl.

The pawl is free to turn about the pivot pin and in the illustrated embodiment is generally L-shapcd. The pawl is proportioned to be unbalanced, to provide a counterclockwise turning moment about the pin 45 as viewed in FIGURE 4, the pawl thus occupying an inclined position wherein the planar under surface 48 of the pawl is downwardly inclined toward the anvil portion 33 of the key receiver slot.

The said under surface 48 forms, in the inclined position thereof, a cam against which the tip and certain upper blade portions of a key K, inserted into the slot, will be engaged. In the initial inserting movements, the key K which is interposed between the. anvil or base 33 and the inclined surface 48 will act to cam the hold down lever 40 clockwise. Further inserting movements of the key K will caus the pawl 41 to rotate about pin 45 from the inclined position illustrated in FIGURE 4 to the horizontal or square position illustrated in FIGURE 5 defined by the rotation limiting engagement between upper surface 49 of the pawl and under surface 43 of the block 42, and hence, the under surface 48 of the pawl will lie substantially parallel with the anvil 33. The outer end 50 of the pawl acts as a stop for positioning locator shoulder 51 of the key K.

From the foregoing it will be observed that during the initial stages of inserting the key, the under surface 48 of the pawl acts as a gradual cam surface, to permit the clockwise shifting of the hold down members with a minimum of effort. After the initial inserting stages, the act of partially inserting the key automatically shifts the stop shoulder 50 into the path of the locator shoulder 51 of the key, to provide an end limit stop and hence to assure a positive axial alignment of the key in the key slot.

It will be understood that after the key and key blank are aligned in their respective slots, the jaw members 22, 23 will exercise their clamping function and the operating mechanism 60 will pivot the hold down members further in a clockwise direction, as shown in FIGURE 6, to permit access to the upper faces of the blade portions of the key and key blank.

The advantages of the novel gravity pawl of the device may be best appreciated by a comparison with the hold down structure of the above noted patent. It will be noted that insertion of a key into the clamp of the patent requires that the nose or tip end of the key be pressed or pried beneath the hold down member, and it may be necessary to resort to progressive canting and levering of the key to secure an initial lift of the hold down members against the relatively stiff springs which urge the hold down members to the seated or locating position.

In addition to the difficulty of inserting the key, where the camming effect of the tip is relied upon, there exists the danger of permanently burring or scarring the upper leading edge of the key, with the result that a subsequent smooth insertion of the key into the plug of a lock may be interfered with. v t

At this juncture it should be observed that any attempts to put a cam surface on the under portion of the hold down as the hold down is illustrated in the aforementioned patent, is likely to cause interference with the aligning function of the outer end of the hold down. Thus, if a cam or bevel were formed on the hold down of the prior device, the insertion of a key having a relatively small shoulder might result in the shoulder of the key engaging against the cam surface, with the result that the key might be shifted an excessive distance inwardly. Since it is necessary for the key and key blank to be precisely axially aligned with respect to each other during the cutting operation, it will be readily appreciated that a positive location of the key and key blank is imperative.

The desired positive location is secured in the present novel hold down herein described and claimed, it is possible to provide a cam surface for facilitating the introduction of a key and key blank without loss of the positive axial locating function which may be achieved only through a perpendicular end portion. The cam surface is, in effect, eliminated after a partial insertion of the key, thus obviating any danger of the key shoulder engaging and lifting the cam surface.

Having thus described the invention and illustrated its use, what is claimed as new and is desired to be secured by Letters Patent is:

1. In a key cutter device or the like, a key clamp comprising an anvil portion for engaging and positioning the base of a key blade, a locator shoulder adjacent said anvil positioned to engage the side face of said blade, clamp jaw means shiftable toward and away from said locator shoulder into engagement with the other side face of said blade for releasably clamping said key against said shoulder, hold down means disposed above and yieldably biased toward said anvil, a pawl member pivotally mounted on said hold down means including a cam surface portion normally inclined toward said anvil, said cam surface being disposed in the path of upper blade portions of a key inserted into said device, and an axial stop shoulder on the outer end of said pawl, said shoulder being normal to the plane of said cam surface and in the path of the shoulder portion of a key.

2.. In a key cutter device'or the like, a key clamp comprising an anvil portion for engaging and positioning the base of a key blade, at locator shoulder adjacent said anvil positioned to engage the side face of said blade, clamp jaw means shiftable toward and away from said locator shoulder into engagement with the other side face of said blade for releasably clamping said key against said shoulder, hold down means disposed above and yieldably biased toward said anvil, a gravity pawl member pivotally mounted on said hold down means including a cam surface portion normally inclined, under the influence of gravity, toward said anvil, said cam surface being disposed in the path of upper blade portions of a key inserted into said device, and an axial stop shoulder on the outer end of said pawl, said shoulder being normal to the plane of said cam surface and in the path of the shoulder portion of a key.

3. In a key cutter device or the like, a key clamp comprising an anvil portion for engaging and positioning the base of a key blade, a locator shoulder adjacent said anvil positioned to engage the side face of said blade, clamp jaw means shiftable toward and away from said locator shoulder into engagement wth the other side face of said blade for releasably clamping said key against said shoulder, hold down means disposed above and yieldably biased toward said anvil, a pawl member pivotally mounted on said hold down means including a cam surface portion normally inclined toward said anvil, said cam surface being disposed in the path of upper blade portions of a key inserted into said device, and an axial stop shoulder on the outer end of said pawl, said pawl and hold down means including cooperating pivot stop portions limiting upward movement of the inner end of said pawl to a position at which said cam surface is substantially parallel with said anvil.

4. In a key cutter device or the like adapted clampingly to support keys and key blanks of a range of sizes, a key clamp comprising a horizontal anvil portion for engaging and positioning the base of a key blade, a locator shoulder adjacent said anvil positioned to engage one side face of said blade, clamp jaw means shiftable toward and away from said locator shoulder for pressing against the other face of said blade and thereby releasably clamping said blade against said shoulder, hold down means disposed above and yieldably biased toward said anvil, said means being pivotal to a position clear of said anvil, a pawl member movably mounted on said hold down means, said member including a cam surface normally inclined toward said anvil, said surface being disposed in the path of the leading portion of a key inserted into said clamp with the base of the blade resting on said anvil, a stop shoulder on the outer end of said pawl, said pawl and hold down including cooperative abutting portions for limiting upward movement of said cam surface to a posi 6 tion whereat said surface is substantially'parallel with said anvil portion.

5. A device in accordance with claim 4 wherein said pawl is pivotally connected to said hold down and is Weighted eccentrically to provide a turning moment about said pivotal connection, thereby to maintain said cam surface in said normal, inclined position.

No references cited.

WILLIAM W. DYER, JR., Primary Examiner.

G. A. DOST, Assistant Examiner.

Claims (1)

1. IN A KEY CUTTER DEVICE OR THE LIKE, A KEY CLAMP COMPRISING AN ANVIL PORTION FOR ENGAGING AND POSITIONING THE BASE OF A KEY BLADE, A LOCATOR SHOULDER ADJACENT SAID ANVIL POSITIONED TO ENGAGE THE SIDE FACE OF SAID BLADE, CLAMP JAW MEANS SHIFTABLE TOWARD AND AWAY FROM SAID LOCATOR SHOULDER INTO ENGAGEMENT WITH THE OTHER SIDE FACE OF SAID BLADE FOR RELEASABLY CLAMPING SAID KEY AGAINST SAID SHOULDER, HOLD DOWN MEANS DISPOSED ABOVE AND YIELDABLY BIASED TOWARD SAID ANVIL, A PAWL MEMBER PIVOTALLY MOUNTED ON SAID HOLD DOWN MEANS INCLUDING A CAM SURFACE PORTION NORMALLY INCLINED TOWARD SAID ANVIL, SAID CAM SURFACE BEING DISPOSED IN THE PATH OF UPPER BLADE PORTIONS OF A KEY INSERTED INTO SAID DEVICE, AND AN AXIAL STOP SHOULDER ON THE OUTER END OF SAID PAWL, SAID SHOULDER BEING NORMAL TO THE PLANE OF SAID CAM SURFACE AND IN THE PATH OF THE SHOULDER PORTION OF A KEY.

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