US2903895A - Mechanical movement - Google Patents

Description

l l l United States Patent MECHANICAL MOVEll/[ENT Joseph Clarence Larsen, Boulder, Colo., assignor to Gates and Sons Inc., Denver, Colo., a corporation of Colorado Application February 25, 1955, Serial No. 490,451

3 Claims. (Cl. 7454) This invention relates to a mechanical movement useful in wire nicking machines; and more particularly, for ma chines for use for nicking wire concrete form ties.

Wooden concrete forms are commonly held together by Wire form ties which prevent the forms from separting under the weight of the concrete; and also, provide a certain degree of reinforcement for the concrete. After the forms have been removed from the hardened concrete, however, the loops on the end of the wire form ties project beyond the face of the concrete thus making it necessary to clip or break off the projecting loops in most instances.

In order to facilitate removal of the projecting portions of the form tie either the top or bottom of the loop is often provided with nicks in the wire so that the loops may be broken off more easily and closer to the surface of the concrete. However, nicking the loops of the wire form tie on the top or the bottom weakens the tie to such an extent that they often break while they are being fastened to the forms. It has been found in accordance with the present invention that this difliculty can be eliminated by nicking the loop of the wire form tie either on the inside of the loop or on the outside rather than on the bottom or the top. Nicking the loop transversely of the plane of the loop does not weaken the wire sufficiently to cause it to break while the form tie is being placed on the form as the forces exerted generally bend the loops upward and downward rather than side to side in the plane of the loop.

The mechanical movement of the present invention has as its principal object the provision of a mechanism for rapidly and economically placing nicks of the required depth transverse to the plane of the closed loops of a wire concrete form tie.

A second object is the provision of a concrete form tie nicking mechanism which is simple to construct, inexpensive, rugged, simple to operate and readily adaptable to many different sizes of wire form ties.

Other objects will be in part apparent and in part pointed out specifically hereinafter in connection with a description of the drawing which follows, and in which:

Figure 1 is a side elevation of a wire nicking machine embodying the mechanical movement of the present invention with parts thereof broken away to conserve space and to show the details of construction more clearly;

Figure 2 is a section taken along line 22 of Figure 1;

Figure 3 is a section taken along line 33 of Figure 1 showing the nicking mechanism in detail;

Figure 4 is a section of the clutch used in the machine taken along line 6-6 of Figure 1 with a portion of the housing broken away to better show the construction;

Figure 5 is a view of the clutch looking in the direction of arrow 7 in Figure 4 with portions of the housing broken away to better show the construction.

Referring now in particular to Figures 1 and 2 of the drawing, reference numeral 10 represents the frame which carries the motor 12, the single revolution clutch 14 and the nicking mechanism indicated in a general way by Patented Sept. 15, 1959 ICC numeral 16. The motor 12 is preferably a gear motor which turns stub shaft 18 interconnecting the motor and driving member 20 of the single revolution clutch at relatively slow speeds. Shaft 22 is mounted for rotation within bearings 24 carried by the frame. The driven member 26 of the clutch is operatively connected to the driving member 20 thereof in a manner which will be described in detail in connection with Figures 6 and 7 and is rigidly connected to one end of shaft 22. Rotational movement is transmitted from shaft 22 to cam shaft 28 by means of chain and sprocket drive 30. Sprocket 32 is preferably one-half the diameter of sprocket 34 so that cam shaft 28 will rotate one-half revolution or 180 for each complete revolution of shaft 22. Cam shaft 28 is mounted for rotational movement within bearings 36 which are fastened to the frame. Cam 38 is splined to cam shaft 28 for longitudinal adjustment thereon; whereas, cam 40 is keyed to the cam shaft. The function and operation of the cams will be described more completely in connection with Figure 3. Supporting members 42 and 44 are mounted on the frame in spaced substantially parallel relationship to form respectively a. head stock and a tail stock. Supporting member 42 is rigidly connected to the frame by means of brackets 46. Bolts 54 fasten brackets 48 to the frame through the aforementioned slots and openings. Supporting members 44 and 42 carry the nicking mechanism 16 which will be described in detail in connection with Figure 3.

, The gear motor 12 rotates stub shaft 18 and drives member 20 continuously. Driven member 26, shaft 22, earn shaft 28 and cams 38 and 40 are normally stopped as the single revolution clutch 14 is disengaged. Pressure upon foot pedal 56 causes the foot pedal linkage 58 to move into the dotted line position shown in Figure 2 thus moving pawl 60 out of engagement with clutch lever 62. This engages the clutch and permits the driving member 20 to rotate the driven member 26 through one complete revolution before the clutch again becomes disengaged. One full revolution of driven member 26 and shaft 22 causes cam shaft 28 and cams 38 and 40 to rotate one-half revolution.

Figure 3 shows the nicking mechanism in detail. Two identical nicking mechanisms are mounted in opposed relation facing one another on each of the supporting members 42 and 44. The nicking mechanism 16 consists of two jaws 64 attached to each of the supporting members 42 and 44 for rockable movement toward and away from one another about spaced pivots 66. The pivots are placed between the ends of the jaws so that the upper ends will move toward one another as the lower ends move away from one another. Rollers 68 are mounted for rotational movement in the lower ends of each jaw in position to engage the elliptical cam surface 70 of earns 38 and 40. The cams have identical cam surfaces and differ only in the manner in which they are attached to the cam shaft. The position of each cam with respect to the cam shaft in normal position i.e., with the single revolution clutch disengaged, is preferably such that the rollers 68 are tangent to the elliptical cam surface on opposite sides of the cam at the ends of its minor axis. Spring means 72 are connected between the jaws to hold the rollers 68 against the elliptical cam surface of the cams. Lugs 74 may be used on one of the jaws to prevent cam 38 from moving along the splined cam shaft 28 during operation of the machine. Each jaw is preferably provided with an adjustment head 76 in opposed relation to one another. Each adjustment head is shown mounted for pivotal movement within the upper end of the jaws about pivot 78 so that they may be adjusted toward and away from one another by means of set screws 80 threaded into the jaws to vary the depth of the nick. A number of other well known means for adjusting the depth of the nick may be used to replace the one shown. An anvil 82 is rigidly attached to the support members and projecting upwardly between the jaws with the cutting edges 84 thereofsubstantially parallel to one another on opposite sidesjfacingithe adjustment heads. Each adjustment head 76 maybe adjusted independently with respect to the anvil by-means of set screw 80in order to regulate the depth ofthe nick. 'Rotation of the cams through one-half revolution will spread. one end of the jawsapart a distance equal to the major axis of the elliptical camsurface and. move the adjustment'heads on the other end toward the anvil thereby forcing portions of a loop against the cutting edges and causing nicks to'be formedin the loop. As the cams return to normal position, spring means 72 acts to separatetheadjustment headsand free the form tie so that it may be withdrawn from the nickin-g, mechanism.

.Figures 4 and 5 are illustrative of one typeof single revolutionclutch 14 that may be employed in the wire nicking machine of the present invention. It has already been mentioned that driving member 20 is continuously rotated. by the motor acting through stub shaft 18; whereas, driven member 26 rotates only when the clutch is engaged. Driven member 26 carries clutch lever 62 mounted for rockable movement upon pivot 100. The clutch lever projects beyond the periphery of the driven member and normally engages pawl 60. .A roller .102is mounted for rotation on the inner end of the clutch lever and is positioned to roll along the inside-rim of driving member .20. The inside rim of the driving member is provided with teeth 10.4 whichengage the roller 102and .cause the driven member to rotate with, the drivingmemher one full revolution when pawl 60 is retracted by means of footpedal 56. Roller 102 normally occupies .the dotted line position shown in Figure 4 when the .clutch is disengaged which permits the driving member to rotate independently of the driven member. The clutch is disengaged when the jaws rotate in the direction of the curved arrow in Figure 4 and strike pawl 60. This causes .theclutch lever torock about pivot 100 against the action oftension spring 106 and moves roller 102 out of engagement with the teeth 10,4 of the driving member. In

order to engage the clutch the pawl 60 is retracted to permit the tension spring 106 to rock the roller 102 upward where it, will be engaged by the teeth of the driving member.

It is obvious that the modification of Figure 3 may be adapted to place the nick in the form tie either in the outside or the inside.

Having thus described the wire nicking mechanism of the present invention in connection with the drawing it .will thus be seen that the many useful and novel objects for which it was. designed have been achieved; and therefore, I claim:

1. In combination: two elongated jaw members mounted in opposed relation for rockable movement about spaced pivot points located between the ends thereof; a

cam shaft mounted for rotation between adjacent ends of the jaws on one side of the pivot points; drive means operatively connected to the cam shaft for effecting r0- tation thereof; clutch means interconnecting the drive means and cam shaft adapted to effect intermittent cyclic rotation thereof through approximately a single cam means mounted on the cam shaft for conjoint rotation therewith, said cam means being operatively connected to said adjacent ends of the jaws to simultaneouslyspread said ends and close. the opposite ends thereof on a work piece when saidcarn means is cyclically rotated; and spring means interconnecting the jaws to hold said adjacent ends in continual contact with the cam means.

2. In combination: two elongated jaw members mounted in opposed relation for rockable movement about spaced pivot points located between the ends thereof; a cam shaft mounted for rotation between adjacent. ends of the jaws on one side of the pivot points; drive means operatively connected to the cam shaft for effecting rotation thereof; clutch means interconnecting the drive means and said cam shaft; means for engaging said clutch means on command and for automatically disengaging said drive to effect intermittent cyclic operation thereof; a single cam means mounted on the cam shaft for conjoint rotation therewith, said cam means being operatively connected to said adjacent ends of the jaws to simultaneously spread said ends and close the opposite ends thereof on a work piece on each cyclic operation of the cam; and, spring means actively interconnecting and biasing the jaws to hold said adjacent ends in continual contact with the cam means.

3. A device in accordance with claim 2, wherein'the cam means is elliptical-shaped and each cyclic operation of the cam shaft produces a rotation thereof of approximately 180".

References Cited in the file of this patent UNITED STATES PATENTS 252,741 Cross Ian. 24, 1882 276,249 Iope et al. Apr. 24, 1883 466,823 Gendron Jan. 12, 1892 671,330 Clemens Apr. 2,1901 970,702 -Goddu Sept. 20, 1910 977,851 Busfield Dec. 6, 1910 1,198,283 Shira Sept. 12, 1916 1,219,170 Shumann Mar. 13, 1917 1,260,260 Harmon Mar. 19, 1918 1,452,224 Smith Apr. 17, 1923 1,565,148 Hoffman Dec. 8, 1925 1,865,309 Evans et al June 28, 1932 1,866,360 Kranz July '5, 1932 2,177,356 Stone et a1. Oct. 24, 1939 2,289,076 Ryan July7, 1942 2,414,906 Seltzer J an. 28, 1947 2,570,919 Cliflord Oct.'9, 1951

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