US3633451A

US3633451A - Key-cutting machine with coordinated positioning and cutting movements

Info

Publication number: US3633451A
Application number: US12697A
Authority: US
Inventors: Nathan S Lieptz
Original assignee: CURTIS NOLL CORP
Current assignee: Curtis Industries Inc
Priority date: 1970-02-19
Filing date: 1970-02-19
Publication date: 1972-01-11
Anticipated expiration: 1989-01-11

Abstract

A key-cutting device having a vertically and transversely movable key blank support member carrying adjustable gauging elements for presetting the depth of cut to be made on the key blank. The support member is lowered into operative position by a cam operating through a lever or rocker arm having a lost-motion connection with the cam to permit overtravel after the support member has attained the limit of its preselected downward movement. The hand lever which is utilized to operate the cam and lower the support member also serves to advance the cutting tool to traverse the key blank. Spring means engage the support member to both retract it from the anvil surface of the cutting machine and elevate it to an inoperative position in response to completion of each cut on the key blank and retraction of the cutting tool. Traversing movement of the key blank is accomplished through a rack-and-pinion arrangement and appropriately spaced detents.

Description

United States Patent Inventor Nathan S. Lleptz Beachwood, Ohio Appl. No. 12,697 Filed Feb. 19, 1970 Patented Jan. 11, 1972 Assignee Curtis Noll Corporation Cleveland, Ohio KEY-CUTTING MACHINE WITH COORDINATED POSITIONING AND CUTTING MOVEMENTS l 1 Claims, 3 Drawing Figs.

Primary Examiner-Gerald A. Dost Attorney-Isler & Ornstein ABSTRACT: A key-cutting device having a vertically and transversely movable key blank support member carrying adjustable gauging elements for presetting the depth of cut to be made on the key blank. The support member is lowered into operative position by a cam operating through a lever or rocker arm having a lost-motion connection with the cam to permit overtravel after the support member has attained the limit of its preselected downward movement. The hand lever which is utilized to operate the cam and lower the support member also serves to advance the cutting tool to traverse the key blank. Spring means engage the support member to both retract it from the anvil surface of the cutting machine and elevate it to an inoperative position in response to completion of each cut on the key blank and retraction of the cutting tool. Traversing movement of the key blank is accomplished through a rack-and-pinion arrangement and appropriately spaced detents.

PATENTEDJANIHQYZ SHEETIUFZ INVENTOR. NATHAN 5. \-\EPTZ x m TO&NEY5

KEY-CUTTING MACHINE WITH COORDINATED POSITIONING AND CUTTING MOVEMENTS CROSS-REFERENCES TO RELATED APPLICATIONS This application is an improvement upon the subject of my copending application Ser. No. 729,281, filed May 15, 1968, and entitled Key Cutting Machine With Preselected Depth Gauging and now Pat. No. 3,469,636.

BACKGROUND OF THE INVENTION In the field of key-cutting machines there are basically two distinct varieties for the purpose of cutting replacement keys. One of these varieties is broadly denominated as a duplicator" which utilizes an existing cut key as a pattern for reproducing the same sequence of cuts on a suitable key blank. The other variety of key cutting machine can be broadly denominated as a code cutter" which does not require an existing cut key as a pattern, but instead utilizes a key or lock number and coded key cuts information to establish settings on the machine which will provide the desired sequence of cuts on a suitable key blank. Both varieties can be either manually or power operated and can be either partially or fully automated.

In my above-mentioned copending patent application, I have disclosed an improved form of code cutter which utilizes a readout" form of preselected depth gauging by means of which the entire code sequence of cuts for the key blank can be preset on the machine before any cuts are made. The present invention relates to new features and improved operating characteristics on the type of code cutter disclosed in the aforesaid copending application.

SUMMARY OF THE INVENTION A code cutter type of key-cutting machine having a vertically movable key blank support member operable by a lostmotion lever linkage, simultaneously with the actuation of the key cutting tool, to position the key blank support member for a preselected depth of cut as predetermined by adjustable gauging surfaces. Yieldable retraction elements engage the Support member for the multifold purposes of elevating the key blank out of the path of movement'ofthe cutting tool after the cut has been completed, and providing a variable spacing between the key blank and the anvil of the machine to accommodate to variations in the thickness of the key blank, as well as to prevent binding between the cutting tool and the key blank during the retractive movement ofthe cutting tool.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view in elevation of the front end ofa key-cutting machine embodying the features of my invention.

FIG. 2 is a view in elevation of the side of the aforesaid keycutting machine, with portions thereof broken away to show detail.

FIG. 3 is an enlarged fragmentary cross-sectional view taken as indicated on line 3-3 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, there is shown a key-cutting machine having a frame or body 11 which has, at one end thereof, an upwardly projecting portion or block 12 and at the other end thereof a depending handgrip portion 13. Secured to the rearward face of the block 12 is a wear surface or anvil 14 having a longitudinally extending aperture 15 therein which also extends through the block 12. Projecting upwardly from the body 11, rearwardly of the anvil 14 is a pillar or post 16 which is surmounted by a finger or upwardly projecting abutment 17.

A sleeve or saddle member 18 is slidably mounted on the post 16 for vertical movement relatively to the body 11. A toothed rack 19 is fixedly secured to the saddle member 18 and serves as a guide rail or track for traversing movement ofa key blank support member 20 which is slidably mounted on the rack 19. The support member 20 carries a pinion 21 which operatively engages the toothed rack 19 and is manipulated by a hand wheel 22 to effect transverse movement of the support member relatively to the rack 19.

The upper portion of the support member is provided with a depth gauge assembly 23 which can be adjusted to establish a predetermined depth of cut for each transverse position of the support member. The depth gauge assembly overlies the abutment or finger 17 which is disposed in the path of downward movement of the support member and engages the depth gauge assembly to limit the extent of downward movement of the support member 20. The forward face of the support member is provided with suitable means, such as the apertures 24, for detachably receiving and positioning any one of many different types of key blank carriages S, depending upon the nature and characteristics of the style of key blank K which is mounted on the carriage and is to be cut in the machine 10. A screw-operated clamping element 25 is mounted on the support member 20 to releasably retain the carriage S and the key blank K in a fixed position on the support member. A detent spring 26 serves to engage appropriately spaced notches on the carriage S to designate the incremental transverse spacing of the cuts on the key blank.

A cutting tool in the form ofa punch 27 is mounted in the body for slidable longitudinal movement through the post 16 and into the aperture 15 so that its cutting edge 28 transverses a portion of the key blank K which is positioned in its path of movement. The punch is provided with a forward extension 29 which rests in the aperture 15 and serves as a guide for the for ward end of the punch during its cutting movement. The rearward end of the punch traverses an upstanding block 30 on the rear of the body 11, which serves as a guide or bearing for that end of the punch. A coil spring 31, which bears against the rear face of the post 16 and bears against a diametrical pin 32 on the punch 27, serves to yieldably maintain the punch in a retracted position with its rearward end bearing upon the upper end of a force-compounding hand lever 33 which is pivotally secured to the body 11 as at 34.

The details and function of the depth gauging assembly, the key blank support member, the anvil, the cutting punch and the hand lever are more fully described in my aforesaid copending patten application, the disclosure of which is incorporated herein by reference.

A rocker arm 35 is pivotally secured to the body 11 rearwardly of the saddle 18, as at 36. The forward end of the rocker arm is bifurcated to provide spaced fingers 37 which are movably accommodated and retained in recesses 38 defined by spaced pairs of projections 39 provided on opposite faces of the saddle member. A flexible element 40 has one end thereof fixedly secured to the rocker arm 35, as at 41, to provide a cantilever which extends rearwardly and whose free end is provided with depending ears 42 in which is jour naled a friction-reducing roller 43. The roller 43 engages a cam surface 44 provided on the upper end'of the hand lever 33. The cam surface has a notch or dwell 45 in which the roller is received and rests when the cutting tool 27 is in its retracted position. An adjustable set screw 46 is threadedly mounted on the top wall of the rocker arm 35 and projects downwardly into engagement with the upper surface of the flexible element 40 at a point intermediate the ends thereof. By rotating the set screw in one direction or the other to vary its effective length and, correspondingly, the extent of force or thrust it exerts upon the flexible element, the degree or extent of stiffness or relative rigidity of the flexible element can be adjustably regulated.

A wire-form U-shaped spring 47 is suitably affixed to the rear block 30, as by plate 48, and has its legs extending forwardly into biasing engagement with the undersurface of the rocker arm 35, so as to urge its forward end upwardly. An ex pansion coil spring 49 extends between the plate 48 and an car 50 on the saddle 18 to normally urge the rack 19 into abutment with the front surface of the post 16. When this abutment condition exists, the opposing surface 51 of the saddle 18 is spaced from the rear face of the post 16 to provide a predetermined clearance on the order of 0.025 inches. The function and purpose of this clearance is to accommodate the support member 20 to variations in the thickness of the key blanks, as will be more fully described hereinafter.

The operation of the cutting machine will now be described. In its normal or inoperative position, the punch 27 is retracted and yieldably maintained in such retracted position by the compression coil spring 31 to the extent limited by the abutment of the hand lever 33 with the body 11, as at 52. The hand lever is in its forwardmost position. In this fully retracted position of the punch, its cutting edge 28 is disposed rearwardly of the key blank carried by the carriage S on the support member 20, so that the key blank K is positioned forwardly of the cutting edge 28 between it and the plane of the anvil 14. It will be understood that, in this inoperative position, the key blank K is not disposed in the path of cutting movement of the cutting tool 27, as the support member 20 is in its fully elevated position where it is yieldably maintained by the urging of the U-spring 47 acting on the rocker arm 35. The engagement of the roller43 of the flexible element 40 in the dwell portion 45 of the hand lever 33 serves to limit. the extent of upward movement of the rocker arm fingers 37 and the support member 20 on the post 16. In this inoperative position, the expansion coil spring 49 yieldably maintains the saddle 18 in itsrearmost position to provide the previously described clearance between it and the rearward face of the post 16.

It is assumed that the multiple adjustable elements of the depth gauging assembly 23 have been prepositioned for the desired sequential depths of cut and the hand wheel 22 has been rotated to cause traversing movement of the support member 20 to the first detent position of the carriage S which represents the first cut to be made on the key blank. In this position, the abutment finger 17 is disposed in registry with the path of movement of the depth gauging element for the first cutting position.

As the hand lever 33 is drawn toward the hand grip 13, it displaces the cutting tool 27 to advance it in opposition to the spring 31 and simultaneously cams the roller 43 to displace the free end of the cantilever arm 40 upwardly to cause downward movement of the rocker arm fingers 37 in an arcuate movement about the pivot point 36, in opposition to the urging of the spring 47. This causes relative downward movement of the saddle 18 and the support member 20 until the depth gauge assembly comes into abutment with the upstanding finger 17. As this point of abutment defining the lowermost position of the support member will vary with the desired depth of cut on the key blank, continued camming displacement of the roller 43 will occur as the hand lever 33 is retracted to the limit of its rearward position. However, the lost motion permitted by the flexibility of the cantilever member 40 allows for this overtravel of the end of the flexible element, even though the pivotal movement of the rocker arm has been arrested prior to the completion of the full stroke of the hand lever.

When the support member 20 and the key blank K have attained their preselected lowermost position, the cutting edge 28 of the punch 27 has not yet been moved forwardly sufficiently to engage the key blank, although the key blank is now disposed in the path of advancing movement of the cutting edge. Theoretically, each general style of key blank has a uniform thickness and its specific carriage S is so dimensioned as to position the key blank on the support member 20 in such forward position as to bring it into a plane coincident with the plane of the surface of the anvil 14, so that the key blank will be in full surface abutment with the face of the anvil when the cutting action occurs. Such full contact or abutment of the key blank with the anvil is desirable in obtaining a clean and accurate cutting action of the cutting tool 27, as well as avoiding or minimizing cocking of the key blank and binding interference with the punch during its retractive movement. However, as a practical matter it has been found that there are manufacturing variations in the thickness of the key blank stock which may increase or decrease its thickness by as much as 0.010 inches from its nominal or standard dimension. For this reason, the specific carriages S cannot be dimensioned to dispose the key blank in the desired plane of abutment with the anvil face, as allowance must be made for an increase in the stock thickness of the key blank resulting from the aforesaid manufacturing variations. Therefore, the carriage must be dimensioned so that even the key blanks which are overly thick will not interfere with the anvil when the support member is lowered to its operative position. Thus the dim ensional arrangement is such that the key blank which is of maximum oversize in thickness will have the most effective abutment with the anvil. Conversely, those key blanks which are of lesser thickness, such as the standard thickness or the undersized key blanks will be disposed in a plane spaced from he surface of the anvil and will not have satisfactory abutment contact, thereby resulting in a poor and inaccurate cut as well as creating the possibility of the cocking of the key blank due to the pressure of the punch with the resultant binding effect and jamming of the punch during its retractive movement. These practical considerations and undesirable consequences are avoided and eliminated by the spring loading of the saddle 18 to provide the above-described clearance between the saddle and the post 16.

With the spring-loaded arrangement of the saddle the key blank is normally maintained rearwardly of the plane of the anvil face regardless of the manufacturing variations of the range normally encountered in the thickness of the key blank. The clearance space of 0.025 inches between the saddle and the post 16 is large enough to compensate for the maximum thickness variation from normal which can be expected in any key blank. It will be noted that when the fingers 37 pivot downwardly to lower the support member 20, they also have a forward vector of movement which, to some extent, displaces the saddle forwardly toward the rear face of the post 16 as the support member reaches its lower limit of position. However, the primary forward displacement of the saddle element 18 occurs as a result of the advancing engagement of the cutting edge 28 with the key blank K which forces the key blank into full surface abutment with the anvil 14 in opposition to the action of the spring 49. The yieldably maintained clearance between the saddle and the post is sufficient to permit this forward displacement.

As soon as the hand lever is initially released, the coil spring 31 causes the cutting member 27 to retract and simultaneously the spring 47 urges the saddle and support member upwardly out of the path of retractive movement of the punch while the spring 49 urges the saddle l8 and support member 20 rearwardly. This movement of the key blank, though initially only light, is sufficient to prevent any binding or jamming between the key blank and the retracting punch. In this manner, the yieldable clearance provided by the spring-loaded saddle accommodates to and compensates for the manufacturing variations in the thickness of the various key blank styles and eliminates the disadvantageous consequences which have heretofore been encountered as a result of such variations.

As the hand lever is further released, the cutting tool 27 and the support member 20 are restored to their initial positions at which the described operating cycle was started. The hand I wheel 22 is now rotated to cause traversing movement of the support member 20 to the detent position defining the second cutting position of the key blank and the operating cycle is repeated with the abutment finger 17 now being disposed in the path of movement of another of the adjustable gauging surfaces of the depth gauge assembly 23. The operative cycle is repeated until all the required cuts have been made. If a duplicate second replacement key is to be made, the cut key blank is replaced with another key blank of the same style and the operative cycle is repeated, without the necessity of changing any of the previously set depth gauge settings on the depth gauge assembly 23.

It will be understood that the degree or quality of flexibility of the cantilever element 41 is a matter of critical sensitivity. If the element 41 is excessively flexible. it will not be rigid enough to overcome the action of the U-spring 47 as the roller 43 is displaced by the cam 44, and the element 41 will simply flex or deform without causing the desired downward movement of the rocker arm fingers 37. On the other hand, if the cantilever element 41 is overly rigid or stiff, it will not permit the necessary lost motion or overtravel in relation to the rotation of the rocker arm 35. This will result in an inability to complete the complete rearward stroke of the hand lever 33 to fully advance the cutting tool 27 after the limit of downward movement of the support member has been achieved. if the hand lever 33 were to be forced beyond this point, injury or deformation to one or more of the operating parts would have to occur. Although the cantilever element 41 could be manufactured to strict specifications of desired flexibility for the purpose intended, such a procedure would result in an excessively exorbitant manufacturing cost for the element. Furthermore, even though the degree of flexibility of the element 41 were initially satisfactory and within the critical limits desired, it would eventually become overly flexible through fatigue and wear in use. These problems are overcome by the previously described arrangement of the adjusting screw 46 to 'vary the degree of operative stiffness or flexibility of the cantilever element 40 as conditions warrant. This arrangement permits accommodation to the wear and fatigue which the element 40 encounters through use as well as minimizing the initial manufacturing cost of the element.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the cope of the subjoined claims.

Having thus described my invention, I claim:

1. In a key-cutting device, the combination of a body, a movable cutting tool carried by said body, a vertically and transversely movable key blank support member mounted on said body for positioning a key blank in selected cutting relationship to said cutting tool, first means yieldably maintaining said support member in a position out of said cutting relationship, second means for actuating said cutting tool, and third means responsive to operation of said second means for mov ing said support member into said cutting relationship in opposition to said first means.

2. A combination as defined in claim 1, wherein said second means comprises a hand lever, and said third means comprises a lever assembly engaging said support member and actuated by said hand lever.

3. A combination as defined in claim 2, wherein said cutting tool is slidably movable on said body into and out of said cutting relationship.

4. A combination as defined in claim 3, wherein said first means displaces said support member in response to movement ofsaid cutting tool out of said cutting relationship.

5. A combination as defined in claim 2, wherein said lever assembly comprises a rocker arm pivotally secured to said body and having one end thereof engaging said support member, cam means provided on said hand lever, and a lostmotion connection provided on said rocker arm and engaged by said cam means to effect displacement thereof.

6. A combination as defined in claim 5, wherein said lostmotion connection comprises a flexible element secured to said rocker arm and defining the other end thereof.

7. A combination as defined in claim 6, including means carried by said rocker arm and engaging said flexible element for adjusting the stiffness of said element.

8. A combination as defined in claim 5, including adjustable gauging means carried by said support member for selectively limiting said rocker arm induced movement of said support member. I

9. A combination as defined in claim 8, wherein said first means maintains said support member in a vertically elevated position, and said rocker arm induced movement is vertically downward.

10. In a key-cutting device, the combination of a body, an anvil provided on said body, a cutting tool mounted on said body for movement into and out ofsaid anvil, a key blank support member mounted on said body for selective movement of a key blank into the path of advancing movement of said cutting tool, whereby said cutting tool presses said key blank into coplanar abutment against said anvil, and means for withdrawing said key blank support member from said anvilengaging position in response to retractive movement of said cutting tool.

11. A combination as defined in claim 10, wherein said means is a spring element engaging said support member and yieldably maintaining said support member in spaced retracted relationship to the plane of said anvil.

Claims

1. In a key-cutting device, the combination of a body, a movable cutting tool carried by said body, a vertically and transversely movable key blank support member mounted on said body for positioning a key blank in selected cutting relationship to said cutting tool, first means yieldably maintaining said support member in a position out of said cutting relationship, second means for actuating said cutting tool, and third means responsive to operation of said second means for moving said support member into said cutting relationship in opposition to said first means.

4. A combination as defined in claim 3, wherein said first means displaces said support member in response to movement of said cutting tool out of said cutting relationship.

5. A combination as defined in claim 2, wherein said lever assembly comprises a rocker arm pivotally secured to said body and having one end thereof engaging said support member, cam means provided on said hand lever, and a lost-motion connection provided on said rocker arm and engaged by said cam means to effect displacement thereof.

6. A combination as defined in claim 5, wherein said lost-motion connection comprises a flexible element secured to said rocker arm and defining the other end thereof.

8. A combination as defined in claim 5, including adjustable gauging means carried by said support member for selectively limiting said rocker arm induced movement of said support member.

10. In a key-cutting device, the combination of a body, an anvil provided on said body, a cutting tool mounted on said body for movement into and out of said anvil, a key blank support member mounted on said body for selective movement of a key blank into the path of advancing movement of said cutting tool, whereby said cutting tool presses said key blank into coplanar abutment against said anvil, and means for withdrawing said key blank support member from said anvil-engaging position in response to retractive movement of said cutting tool.