US3215461A - Knotter lock - Google Patents

Description

B. L. LURIE KNOTTER LOCK Nov. 2, 1965 2 Sheets-Sheet 1 Filed 001:. 2, 1963 INVENTOR BENJAMIN L LURIE 6 MW Wm W, Y.

1965 B. LURIE 3,215,461

KNOTTER LOCK Filed 001;. 2, 1963 2 Sheets-Sheet 2 INVENTOR. BENJAMIN L. LURIE BY 9mm, 09mm, 06mm, (64 dlttgs.

United States Patent 3,215,461 KNOTTER LOCK Benjamin L. Lurie, Chicago, Ill., assignor to B. H. Bunn Company, Chicago, 11]., a corporation of Illinois Filed Oct. 2, 1963, Ser. No. 313,221 Claims. (Cl. 289-18) This invention relates to tying machines and particularly to the construction of the knotter mechanism thereof.

In a tying machine presently commercially available the knotter mechanism includes a twine-holding beak which is mounted on a rotatable shaft driven from an interrupted gear through intermediate bevel gearing. A leaf spring bearing against a cam surface on a lever in continuous contact with the beak is depended upon to hold the beak in a predetermined position relative to the remainder of the tying apparatus during such times as the beak is not in operation. During a tying operation it may occur that the knot is not released at the time it is expected to be free of the beak, and the operator, unaware that he is required to wait a second longer for the release to take place, may jerk the tied bundle to tear it free of the machine. The unsevered twine exerts a severe pull on the beak and rotates it out of the position intended for it by the leaf spring and cam. Due to the construction of the cam, the beak may remain in its turned position andbe as much as 45 out of phase with its drive gear in the subsequent operation of the machine. This in turn results in a malfunction of the machine and in a possible destruction of the drive for the knotter.

It is an object of this invention to provide means for ensuring a predetermined phase relation between a knotter beak and its associated apparatus in a tying machine of the type described above, such that the beak will be unaffected by forces extraneous to those used to drive it.

More specifically, it is Within the purview of this invention to provide an automatically operated latching mechanism for the beak of a knotter which will become effective to hold the knotter against rotation immediately upon the release of the knotter beak drive by the interrupted gear of such drive.

These and other objects of this invention will become apparent from the following detailed description of the preferred embodiment thereof described below and shown in the accompanying drawings in which:

FIG. 1 is a perspective view of a knotter of the prior art and of an interrupted gear by which the knotter is driven;

FIG. 2 is a fragmentary perspective view corresponding to FIG. 1, showing the knotter locking mechanism of this invention applied to the prior art knotter;

FIG. 3 is an enlarged, exploded perspective view of the locking mechanism;

FIG. 4 is a side elevational view of the knotter locking mechanism about to be released by a portion of the gear which drives the knotter;

FIG. 5 is a side elevational view corresponding to FIG. 4, showing the locking mechanism released;

FIG. 6 is a plan view of the locking mechanism, and

FIG. 7 is an end elevational view of the locking mechanism of FIG. 6.

The problem to the solution of which this invention is addressed is best illustrated in FIG. 1, wherein that portion of a well known tying machine incorporating the knotting mechanism and the drive therefor is shown. Said knotting mechanism is comprised of a frame 10, which may be a machined casting having a bearing 11 adapted to swing about a fixed pivot 12 in response to reciprocating motion imparted to the end 13 of an arm 14 thereof by an appropriate camming mechanism (not shown) forming part of the said well known tying machine. Frame 10 supports a shaft 15 rotatable about an axis disposed generally transversely to the axis of pivot 12 and driven by a pinion 16 secured to one end of said shaft 15. At the opposite end of said 15 is a bevel gear 17 meshing with another bevel gear 18 secured to a shaft 19 rotatable about an axis generally perpendicular to the axes of shaft 15 and pivot 12, and also supported for such rotation in frame 10.

Shaft 19 drives a knotter shown generally at 20, said knotter including a knotter beak 21, which, in the operation of forming a knot, is adapted to hold and manipulate a section of twine 22. Rotative movement of beak 21 is restrained by a lever 23 pivoted at 24 to frame 10 and provided with a cam portion 25 adapted to contact the stem 26 of beak 21, and with a second cam 27 which is continuously contacted by a leaf spring 28 secured at 29 to frame 10. Lever 23 is normally maintained by leaf spring 28 in a position to hold beak 21 in the dotted position shown in FIG. 1. In such position beak 21 is at the commencement of a cycle of operation and it is important that the cycle of operation commence with the beak in this position to ensure a proper phase relation between the beak and the remainder of the tying mechanism of the machine.

The drive for pinion 16 is an intermittent one and is provided by a rack 30 in the form of a gear segment secured to an arm 31 rotatable about an axis 32 during a portion of the knot tying cycle. Thus there are prolonged intervals during which pinion 16 is not in contact with rack 30 and therefore said pinion 16 and shaft 15, bevel gears 17 and 18, shaft 19, and beak 21, are free to turn, except for such restraint as is imposed upon the turning of beak 21 by lever 23. It may be appreciated that the sudden engagement of rack 30 with pinion 16 requires a precise orientation of pinion 16 relative to the teeth of rack 30 so that the first tooth of said rack 30 does not engage an end of a tooth rather than enter between two adjacent teeth. Some slight misorientation is made possible by forming one of the teeth with relief 33 so that the first tooth of the rack 30 may pass through a zone which might otherwise be occupied by a portion of a tooth of pinion 16, and into contact with the tooth adjacent the one having a relief, thereby insuring a proper engagement between pinion 16 and rack 30. It becomes important therefore that pinion 16 always be oriented with respect to rack 30 in a manner to present the increased space provided by the relief at 33 to the first tooth of the rack 30.

During a knot tying operation, a predetermined time interval is required between the initiation of the operation and its termination. The movements of the knotter and its beak 21 are not visible to the operator, so that he may misjudge the time at which the tying cycle is completed and the tied twine is severed from that remaining in the machine. If he should attempt to remove the bundle from the tying machine prior to the completion of the tying of the knot, a sudden pull is exerted upon twine 22, which tends to rotate beak 21 about its shaft 19 against the restraining action of leaf spring 28 upon lever 23, with the result that said beak remains in its turned position. The rotation of beak 21 is accompanied by a similar rotation of shaft 19, bevel gears 18 and 17, shaft 15, and gear 16, so that the tooth having the relief 33 is rotated out of its proper orientation relative to rack 30. The entire knotting mechanism is thus out of phase with the remainder of the machine and serious damage to the knotter can result.

The manner in which the above described problem is solved by the present invention is shown in FIGS. 2 to 6,'

inclusive. In general, I provide a latch which is automatically operable at the proper times to engage a tooth of pinion 16to hold said pinion and the entire train of mechanisms from the pinion to and including the knotter beak 21 against rotation relative to frame 10. The latch is automatically released by a portion of the drive gear for the pinion just prior to the engagement of the pinion by the gear. The proper phasing of the operation of the latch insures holding the beak 21 in its desired starting position after each knot-tying operation, regardless of any unwarranted external forces which may be applied to twine 22, after pinion 16 is disengaged from rack 30. The pinion holding means is shown more clearly in FIGS. 2 and 3, to which reference is now made.

The pinion holding means is comprised, in general, of a latch 34,pivotally mounted on a bracket 35, which is secured to frame 10 in a manner not to interfere with the functioning of any of the remaining mechanisms of the knotter. In the prior art tying machine, rack 30 is formed as a separate gear sector which is then appropriately secured to a rotatable arm 31 provided with a surface 36 having a circular contour disposed adjacent and below, or radially within the teeth of rack 30. The leading edge 60 of surface 36 is chamfered for the purpose of this invention to provide an abutment adjacent surface 36, the function of which will be hereinafter described. It is the rotatable arm of the existing tying machine which is utilized to time the operation of the latch so that it is released when rack 30 engages pinion 16 and is immediately applied when rack 30 disengages said pinion 16.

Latch 34 is comprised of an arm 37 on which is formed a cam 38 having a first cam surface 39 and a second cam surface 40, angularly disposed with respect to cam surface 39 and adjacent thereto, formed on the end thereof. One end of arm 37 is bent at right angles to the general plane of said arm to form a pawl 41 having a tooth 42 adapted to be received between adjacent teeth on pinion 16. Pawl 37 is pivoted at 43 upon a pin 44 secured at 45 to bracket 35.

Bracket 35 has a series of tabs formed thereon, the first of which 46 is provided with an opening 47 through which passes a screw 48 by which the bracket is secured to frame 10. A second tab 49 is similarly provided with an opening 50 through which passes a screw 51 by which tab 50 is secured to another surface on frame 10. The two points of support, namely, screws 48 and 51, additionally provide a means for preventing bracket 35 from turning relative to frame 10.

It is intended that latch 34 be disposed in coplanar alignment with arm 31 and that bracket 35 be disposed beside rack 30, which makes it necessary, therefore, to space latch 34 from bracket 35. The correct, spacing is provided by a bushing 52 mounted on pin 44 between latch 34 and bracket 35. Latch 34 is retained on pin 44 by a snap ring 53.

It is contemplated that latch 34 will be continuously urged in a direction to cause tooth 42 thereof to enter between two adjacent teeth on pinion 16. Such bias is provided by a spring 54 which is retained between a tab 55 extending laterally from latch 34 and the third tab 56 on bracket 35 which extends laterally over tab 55 and is provided with a pin 57 for retaining spring 54 thereon. Referring now to FIGS. 4 and 5, the operation of the latch will now be described. In FIG. 4 it may be observed that latch 34 is in its lower position in which tooth 42 is disposed between two adjacent teeth of pinion 16 to hold said pinion against rotation. The tooth having the'relief 33 is immediately adjacent rack 30, and the first tooth 58 of said rack 30 is about to engage the tooth 59 adjacent the one with relief 33. Arm 31 rotates in a counter-clockwise direction as viewed in FIG. 4 and chamfered corner or abutment 60, as shown in FIG. 4, is just contacting the cam surface 39 on latch 34. Said surface 39 is disPOSfid at an angle with respect to surface 36 so that continued rotation of arm 31 causes abutment 60 to cam said surface 39 radially outwardly with respect to rack 30, and the associated latch 34 to be rotated in a counter-clockwise direction about its pivot 43, thereby raising tooth 42 from pinion 16 and disengaging said tooth from the teeth of said pinion.

In FIG. 5 latch 34 is shown in its raised position with cam surface 40 thereof riding on surface 36 to hold said latch on its raised position. In such position, pinion 16 is free to turn as it is driven by rack 30, and in this manner the normal knot-tying functions of knotter 24 may be performed. When surface 36 has passed completely under cam surface 40, spring 54, which has been holding latch 34 down and urging cam surface 40 into contact with surface 36, will cause latch 34 to drop down and engage pinion 36, thereby holding said pinion against further rotation. The disposition of surface 40 relative to surface 36 is such that latch 34 will drop down to have its tooth 42 engage pinion 16 when rack 30 has disengaged itself from said pinion 16. In this position the tooth having the relief 33 will be oriented in the position shown in FIG. 4 and the knotter will be in condition to commence the next knotting operation. If any external force is applied to twine 22 after tooth 42 engages pinion 16, said force can have no effect upon beak 21, nor upon any of its associated drive mechanism to throw said beak or its drive mechanism out of phase with the remainder of the tying machine.

Bracket 35 and latch 34 are preferably made as stampings so as to require a minimum of machine work. The only additional machine work required on the knot-tying apparatus to accommodate latch 34 is the machining of surface 36 which normally would be unfinished, since it previously performed no useful function. It will also be necessary to drill and tap the openings in frame 10 to receive the screws 48 and 51 by which bracket 35 is attached to said frame. The space occupied by the bracket and latch is available on the existing machines and does not require a modification of any of the associated or adjacent mechanisms for its provision. This is true in all phases of the operation of bracket 10 including those wherein it is oscillated about pivot 12 in the further operation of the knotting machine.

It is understood that the foregoing description is merely illustrative of a preferred embodiment of this invention and that the scope of this invention is not tobe limited thereto, but is to be determined by the appended claims.

I claim:

1. In combination, a rotatable knotter beak, intermittent drive means for the beak including a pinion gear and an interrupted gear adapted to engage and drive the pinion gear, and latch means for engaging said pinion gear to hold said gear against rotation.

2. The combination described in claim 1, comprising additionally a surface movable with the interrupted gear, and cam means on the latch adapted to be engaged by the surface prior to the engagement of the pinion by the interrupted gear to disengage said latch from said pinion gear.

3. In combination, a frame, a shaft mounted on the frame, a knotter beak secured to said shaft, means for rotating said shaft, said means including a toothed pinion secured to said shaft, an interrupted gear adapted to engage and drive the pinion, latch means including a latch and a pivot support therefor mounted on said frame, said latch having a tooth adapted to enter between adjacent teeth on the pinion, resiilent means on the pivot support and bearing against the latch to urge the toothon the latch to enter between adjacent teeth on the pinion, and means movable with the interrupted gear for engaging the latch and moving said latch away from the pinion against the action of said resilient means, to thereby withdraw the tooth of the latch from between the teeth of the pinion.

4. The combination as described in claim 3, said pivot support for the latch comprising a bracket rigidly secured to said frame, a pivot on said bracket, said latch being mounted on said pivot and spaced from the bracket, and said resilient means comprising tabs on the bracket and latch and a spring in compression between the tabs urging said tabs apart.

5. The combination as described in claim 3, said latch having a first cam surface, and a second cam surface adjacent the first cam surface, and said means movable with the interrupted gear comprising an abutment rotatable with said interrupted gear to engage and cam References Cited by the Examiner UNITED STATES PATENTS 1,387,051 8/21 Hathaway 289-6 DONALD W. PARKER, Primary Examiner. RUSSELL C. MADER, Examiner.

Claims (1)

1. IN COMBINATION, A ROTATABLE KNOTTER BEAK, INTERMITTENT DRIVE MEANS FOR THE BEAK INCLUDING A PINION GEAR AND AN INTERRUPTED GEAR ADAPTED TO ENGAGE AND DRIVE THE PIN-

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