US 3432623 A
Description (OCR text may contain errors)
March 11, 1969 4 c. H. BLANCH ET AL 3,432,623
REEL CONSTRUCTION HAVING IMPROVED RATCHET AND- PAWL Filed Jan. 20. 1967 IN VEN TOR 5 Charles H. Blah e 1' BY enrq F Olzdk z a zmsv United States Patent 3,432 623 REEL coNsrRUcTroN HAVING IMPROVED RATCHET AND PAWL Charles H. Blanch, Maple Heights, and Henry F. Olzak,
Independence, Ohio, assignors to Alert Stamping and Mfg. Co., Inc, Redford Height, Ohio, a corporation of Ohio Filed Jan. 20, 1967, Ser. No. 610,573 US. Cl. 19112.2 Claims Int. Cl. H02g 11/02 ABSTRACT OF THE DISCLOSURE Background of the invention and summary Although the following description refers principally to a reel and cord structure, it is understood that the improved ratchet and pawl structure of the invention is adapted as well for all types of drums, spindles, sheaves, or the like designed to pay out and receive a cord, rope, strand, cable, or other like members.
Cooperating ratchet and pawl structures have been suggested to arrest the turning of a reel at one of several selective rotary stations when the length of the cord released or paid out reaches a desired length. The ratchet and pawl are subsequently disengaged to release the reel at such an arrested station when it is desired to return or rewind the cord back onto the reel. One type of structure that has been used for this purpose includes the so-called gravity-operated pawl. More particularly, to stop a rotating reel, a pawl pivotally mounted on the reel engages a relatively stationary ratchet carried by a shaft around which the reel turns. Upon later break ing this connection between the ratchet and pawl and rewinding the cord or the like back onto the reel, the reverse rotation of the reel causes the pivotally mounted pawl to swing away from the ratchet (said to be due to gravity and hence the name but more accurately due to centrifugal force), thereby insuring that the pawl does not interfere with the rewinding step by inadvertent engagement with the ratchet until the reel again comes to rest.
While such a ratchet and pawl construction has in general been satisfactory, problems in operation arise when the pawl over-rotates or is thrown through too great an angle. I
The pawl literally flips out of position and thereafter is unable normally to engage and/ or disengage the ratchet as desired. To prevent this, some ratchet and pawl structures of the gravity-operated type have included additional parts and equipment, such as a retaining cup, designed to hold the pawl in a reasonably captive position. Such additional parts naturally increase the manufacturing costs of the reel and still may notguarantee satisfactory performance of the pivoted pawl.
. In accordance with the present invention, the problems of over-pivoting the pawl are solved solely by the design of the pawl itself. The present pawl is so constructed that it can assume substantially only two positions, either engagement or limited disengagement with the ratchet. As a result, no additional protective parts or external equipment is needed for holding the pawl relatively captive.
It is, therefore, a primary object of the present in- Patented Mar. 11, 1969 vention to provide an improved ratchet and pawl structure for a reel or the like.
, Another object is to provide a ratchet and pawl structure of so-called gravity-operated type wherein a pivotally mounted pawl cannot over-pivot to an inoperative position where subsequent engagement with the ratchet is difficult if not impossible to realize.
A further object is to provide a ratchet and pawl structure wherein over-pivoting of the pawl is prevented by the design of the pawl itself and without the need for auxiliary parts for this purpose.
Other objects and advantages will be apparent from the following disclosure and drawing wherein:
FIGURE 1 is a radial cross-sectional view of a reel embodying the present invention;
FIGURE 2 is a right hand side view of FIGURE 1 with a cover plate removed, the pawls illustrating different possible positions with respect to a ratchet;
FIGURE 3 is a radial cross-sectional view of an electric cord reel assembly embodying the present ratchet and pawl structure;
FIGURE 4 is a fragmentary right hand side view of FIGURE 3 with the outer housing removed; and
FIGURE 5 is a fragmentary view of a contact block for maintaining a constant electrical connection between an alternating current supply and an electric cord of the reel of FIGURE 4.
In one form, the present invention embodies a reel construction or the like having a shaft member and a reel member mounted with respect to each other for relative rotation. Ratchet means carried by one of the members has at least one recess and a riding surface.
Pawl means carried by the other of such members is provided with a lock portion to engage such recess, and thereby fix the members one to the other, and a riding portion to engage the riding surface of the ratchet means when the lock portion of the pawl and recess are disengaged. The resulting riding action limits the extent of the disengagement between the pawl and ratchet.
Referring initially to the embodiment of FIGURES 1 and 2, a reel or sheave 10 is mounted to turn freely about a shaft 11 which, if desired, may be suitably supported with respect to a stand, wall, etc., by conventional means. The reel 10 has a laterally projecting handle 12 by which manually to turn the reel about the shaft and carries a cord 13 or the like wound about the core of the reel 10.
At one end, the shaft 11 is upset to retain a washer 14 which facilitates the relative rotation between the real and shaft. At the other end, the shaft 11 has a circumferential groove 15 to receive and hold a ratchet 16. As shown by FIGURE 2, the shaft 11 has flat sides or lands which fit through a matching opening in the ratchet 16. This mating construction enables the ratchet 16 to resist turning with the reel 10 without the addition of other parts to accomplish this purpose.
The ratchet 16 is generally disc-shaped and has a plurality of recesses 17 on its periphery which are spaced apart by riding surfaces defined by intervening, arcuate, circumferential edges of the ratchet 15. The ratchet can have any reasonable number of recesses 17, including only one, but'normally three provide good performance, even if only one pawl is used.
Pawls 18, 19, and 21'} are pivotally mounted with respect to the side of the reel 16 adjacent the ratchet 16 and may be protected by a cover plate 21 suitably secured to the same side of the reel as by spot welding. Alternatively, tabs stuck from the side of the reel 10 can be used to retain the plate 21. Any reasonable number of pawls can be used, including only one, but usually three pawls are used, one for each indicated recess. Each pawl is pivoted intermediate its ends as by a rivet and has adjacent one end a radially (with respect to the reel) inwardly turned hook or lock portion 22. This lock or heel is designed to engage in a fairly snug fit any of the recesses 17. The other end of each pawl tapers somewhat and has a curved riding portion 23 on a side facing the ratchet of a curvature substantially matching that of a riding surface 24. The hook portion side of each pawl from the pivot point is normally heavier than the riding portion side of the pawl.
In operation, the cord 13 is pulled from the reel 10, thereby rotating the reel with respect to the shaft 11. During this action, the reel turns clockwise as viewed in FIG- URE 2, and centrifugal force pivots each pawl to an outward position free of engagement with any recess 17 of the ratchet 16. At the same time, however, the riding portion 23 of each pawl nests against and rides the surfaces 24 of the ratchet. The length of such riding portion 23 is sufficient to bridge across any of the recesses 17 and prevent untimely engagement with the artchet. At this time, the pawls are substantially in the position shown by pawl 18 of FIGURE 2.
When the length of the released cord 13 reaches a desired extent, the reel slows in its rotation due to a lessening pull. This enables the hook portion 22 of a pawl to rotate toward the ratchet 16. At this time, the pawls are substantially in the position shown by pawl 19 in FIGURE 2. The pawls now enter recesses 17 thereby fiving the reel and shaft 11 with respect to each other. At this time, the pawls are substantially in the position shown by pawl 20 in FIGURE 2.
To rewind the cord 13 onto the reel 10, a slight outward tug on the cord breaks the engagement between the ratchet and pawls, and the reel can then be rotated in a reverse direction (counterclockwise as viewed in FIGURE 2) as by the handle 12. Again the pawls are thrown outwardly by centrifugal force disengaging the ratchet. The riding portions 23 of the pawls smoothly ride over the surfaces 24 of the ratchet and limit the extent of such disengagement.
It is important to note that in either case, whether the cord 13 is being paid out or retracted, the pawls 18, 19 and 20, by their construction cannot be over-pivoted or so thrown outwardly as to prevent subsequent re-engagement with the ratchet 16. Further this is accomplished without the need for auxiliary equipment with respect to the pawls.
The embodiment of FIGURES 3 through 5 illustrates the adaptation of the present invention to an electric cord reel. In this embodiment, screws 26 hold cooperating bowl-shaped outer sections 27 and 28 to the ends of a shaft 29 having stepped axial sections to receive parts hereinafter mentioned. An elastomeric band 31 has grooves along its sides to receive the edges of the sections 27 and 2S and define therein a housing for an electric reel. A commutator block 32 freely rides the shaft 29 and is secured by a rivet 33 to a radially extending web portion 34 of a reel generally indicated by R. The Web portion 34 terminates in a trough portion 36 formed along the outer periphery of the reel R. l
Several turns of an insulated electric cord 37 having dual conductors nest within the trough 36, the outer end leaving the housing through a peripheral opening (not shown) in the sections 27 and 28, An electric potential is supplied to the inner end of the cord 37 through an inlet conductor 38 which enters the section 27 through an offset portion 39 and connects its two leads 40 (FIGURE 5) to contact brushes 41 and 42, respectively, supported on a contact block 43. A rivet 44 secures the block 43 to section 27, the block 43 having an opening freely to pass the shaft 29. The commutator block 32 has inner and outer commutator rings 46 and 47 which engage the contact brushes 42 and 41, respectively, and thereby transfer an electric potential in a conventional manner to the dual co uc f he cord 7, he inner e ds of h ch a e soldered to metal clips 35 contacting the rings 46 and 47.
The reel R includes means to oppose yieldingly its relative rotation about the shaft 23 in a direction to pay out the cord 37 and thereby also effective to urge the return of the reel to its original position with respect to the shaft. In the form illustrated, the reel is rotated by an outward pull on the cord 37 and against the resistance of a spirally coiled spring 49. A rivet 50 fixes an inner end of the spring 49 to the shaft 29, while another rivet 51 secures an outer end of the spring 49 to the trough 36. A circular separator plate 52 freely fits over the shaft 29 and has an inwardly turned rim which is suitably fixed as by spot welding to an underside of the trough 36.
A series of pawls 52, 53 and 54 are pivotally secured intermediate their ends as by rivets to the plate 52 for engagement with a ratchet 55. The shaft 29 receives and holds the ratchet against rotation by means of flats or lands on opposite sides thereof which match a central opening in the ratchet 55. The pawls 52, 53 and 54 have the same general construction as that described for the pawls of FIGURE 2 including a hook or heel portion 56 and a riding surface 57. As with the previously described embodiment, at a given instant, all pawls occupy substantially the same position relative to the ratchet 55, the different pawl positions in FIGURE 4 being shown for purposes of illustration.
The reel assembly of FIGURES 3 to 5 may be adapted for many applications. For example, the reel may be attached to the end of a tank-type vacuum cleaner. In use, the cord 37 is pulled from the reel assembly, the reel R rotating until a sufiicient length of cord has been paid out. The action of the pawls 52, 53, and 54 is similar to the embodiment previously described. For example, during the paying out of the cord 37, centrifugal force pivots the pawls to an outward position free of engagement with ratchet 55, so that the pawls at this time are substantially in the position illustrated by pawl 52 in FIGURE 4. As the reel slows in its rotation, the hook portion pivots toward a recess 58, so that the pawls at this juncture are substantially in the position shown by pawl 53 in FIGURE 4. Finally, when a pawl has nested within a recess 58, the union between the ratchet and pawl is complete and each is locked with respect to the other. At this time the ratchets are in the position substantially shown by pawl 54 in FIGURE 4. The release of the pawls with respect to the ratchet is accomplished by a short outward tug on the cord 37, after which the energy stored in the tightened coil spring 43 returns the cord onto the reel R. During this time the action of the pawls 52, 53, and 54 is the same as that previously described.
It will now be apparent that the present invention provides an improved ratchet and pawl construction for a reel or the like. The pawl of the present structure cannot be over-pivoted to an inoperative position where subsequent engagement with the ratchet is difiicult or impossible. Moreover, this is accomplished without the need for auxiliary parts to hold the pawl relatively captive.
1. In a reel construction or the like having a shaft and a reel mounted on the shaft for pay-out rotation or reversible receiving rotation, a ratchet carried by the shaft having at least one recess .and a riding surface, pawl means pivotably carried by the reel having a lock portion to en gage said recess, thereby to fix the ratchet and pawl means together, and a riding portion to engage said riding surface when the lock portion and recess are disengaged, thereby to limit thegextent of such disengagement, said riding portion being the leading end of the pawl means during pay-out rotation of the reel and having a length sufiicient to bridge across said recess of the ratchet and prevent inadvertent engagement therewith.
2. The reel construction of claim 1 wherein said riding surface of the ratchet is arcuate, said lock portion of the pawl means is a hook portion, and said riding portion gen- 5 erally matches the curvature of said arcuate riding surface of the ratchet.
3. The reel construction of claim 1 wherein the lock portion of the pawl means is heavier than the riding portion.
4. The reel construction of claim 1 wherein said lock portion normally engages said recess of the ratchet upon receiving rotation of the reel.
5. The reel construction of claim 1 further including mean yieldingly opposing the rotation between the shaft member and reel member in one direction and efiective to urge the return of said members to their original positions.
6. The reel construction of claim 1 wherein the ratchet has a plurality of said recesses and the reel has a pawl means for each of said recesses.
7. The reel construction of claim 1 wherein the ratchet is generally disc-shaped and has a plurality of said recesses on its periphery which are spaced apart by riding surfaces defined by intervening, arcuate, circumferential edges of such disc-shape.
8. The reel construction of claim .1 where said pawl means is pivotally mounted on said reel intermediate the lock portion and the riding portion.
9. The reel construction of claim 1 wherein said reel contains a cord or the like adapted to be paid out and collected on said reel member.
10. The reel construction of claim 9 wherein said cord is an electroconducting cord, and the reel construction further includes electrical input means to impress an electrical potential on said cord.
References Cited UNITED STATES PATENTS WILLIAM S. BURDEN, Primary Examiner.