US2976959A

US2976959A - Ratchet device

Info

Publication number: US2976959A
Application number: US655613A
Authority: US
Inventors: Lawrence E Husted
Original assignee: American Machine and Metals Inc
Current assignee: American Machine and Metals Inc
Priority date: 1957-04-29
Filing date: 1957-04-29
Publication date: 1961-03-28
Anticipated expiration: 1978-03-28

Description

March 28, 1961 L. E. HUSTED RATCHET DEVICE 4 Sheets-Sheet 1 Filed April 29, 1957 all 1 FIG.

INVENTOR.

LAWRENCE E. HUSTED BY Awmvfju- ATTORN EYS March 28, 1961 L. E. HUSTED 2,975,959

RATCHET DEVICE Filed April 29, 1957 4 Sheets-Sheet 2 INVENTOR.

LAWRENCE E. HUSTED ATTORNEYS March 28, 1961 E. HUSTED 2,976,959

RATCHET DEVICE Filed April 29, 1957 4 Sheets-Sheet 3 FIG. l5. Fl G. l6. INVENTOR.

LAWRENCE E. HUSTED EWMMWL ATTORNEYS March 28, 1961 E. HUSTED 2,976,959

RATCHET DEVICE Filed April 29, 1957 4 Sheets-Sheet 4 Fl G. 22.

INVENTOR.

LAWRENCE E. HUSTED BY FIG. l8.

2 O 4 mm 2 l P G W, Lu, F

ATIORNE'Ys RATCHET DEVICE Lawrence E. Hosted, Fairhill, Pa., assignor, by mesne asslgmnents, to American Machine and Metals, Inc., New York, N.Y., a corporation of Delaware Filed Apr. 29, 1957,. Ser. No. 655,613

3 Claims. (Cl. 188-82.7)

This invention relates to a ratchet device. More particularly, it relates to such a device having a toothed ratchet member and a pawl on separate relatively movable members. Particular utility for the device of this invention is found in connection with a member which is biased to move in one direction and which is free to be moved in the opposite direction.

The ratchet device of this invention, for example, can be controlled to act as a stop preventing the movement of a member in the direction in which it is biased or, alternatively, to freely permit such movement, the action of the ratchet device being entirely controlled through the movement of the said member. I

The device in accordance with this invention is highly advantageous due to the fact that it is very sensitive to control, avoids complex mechanisms and is inexpensive to fabricate. p

Further, the device of this invention is highly advantageous due to the shortness of travel of a movement member required to efiect the desiredjcontrol.

The ratchet device of this invention can be employed with a wide variety of devices having relatively movable members of, for example, a rotary or linear nature.

The invention will be made clear by a study. of the following description in conjunction with the drawings in which: 7

Figure 1v is a front elevation of a self-retracting reel. embodying a ratchet device in accordance with this invention.

Figure 2 is a section taken on the planes indicated by the line 22 in Figure 1. j I h Figure 3 through 14 are schematic views showing the various relative positions of the pawl supporting the pinand ratchet wheel of thereel of Figure 1 in various steps of the operation of the reel. j Y Figures 15 through 1'] are schematic views showing the relative positions of the pawl mounting pin, ratchet wheel and pawl camming pin of the reel of Figure l during the operation of the pawl camming pin.

Figure 18 is an elevation of the ratchet-pawl mechanism in accordance with this invention applied to a window sash and frame.

Figure 19 is a horizontal section taken on theplane indicated by the line 19l.9 in Figure l8.

Figure 20 is an alternative ratchet-pawl mechanism adapted to be used with members having relative linear movement showing the mechanism in the locked position. I Figure 21 is a view of the ratchet-pawl mechanism of Figure 20 showing it in the unlocked position.

Figure 22 is a side'elevation of the ratchet-pawl mechanism shown in Figure 20. l 1

Figure 23 is a front elevation of. analt'ernative ratchetpawl mechanism in accordance with this invention. Figure 24 is a s ection taken on theplanes indicated by. the line- 24 -24 in Figure 23. 3

' Figure :25 is a front'elevation of the ratchet-pawllrnechf -140mm. p, 'Alth'ougb'not essential tothe'proper operation of th'e Meat 0 anism of Figure 23 showing the mechanism in the lockedv position.

As shown in Figures 1 andy2, a self-retracting reel 2 is provided with a drum 4 formed from

members

6 and 8 which are welded together. tia-lly coiled on drum 4.

Member 6 of drum 4 is brazed to a hub 10 which is secured by a pressed fit to a bearing 12 which rotates on arbor 1'4. Arbor 14 has a nut 16 which is threaded over.

threaded end 18 in order to secure arbor 14 fixedly to any. desired supporting structure, arbor 14 thus being malintained against rotation during the operation of the tee The reel 2 is provided with a spring motor to provide for the automatic rewinding of cable 9. Any conventional motor can be employed such as, for example, a spiral type spring motor which is widely used in connection tion with self-retracting reels and which is illus-.

and is merely illustrative of a rotary structure in connec tion with which the ratchet-pawl device in accordance with this invention can be usefully employed. The'novelv aspects of the reel 2 embodying a device in accordance. with this invention will now be described.

A'ratchet wheel 36 is fixedly secured to arbor 14 at 38 and is providedwith teeth 40. A bracket 42 is' secured to member 6 and carries a pin 44having an enlarged head 46. A pawl 48 lying in substantially the same plane as ratchet teeth 40 is provided with a slot 50. engaged by pin 44. Pawl 48 is maintained on pin 44 by a clip 52 secured in channel 54 in pin-44.

The center "of pawl 48 is biased downwardly by a' torsion spring 56. Spring56 has an end 58 which passesthrough opening 60 in bracket 42 and its other end 62 passes through an openingv 64 on the center line of pawl 48 It will, of course, be apparent that spring 56 is twisted prior to the insertion of the

ends

58 and 62 into their respectiv Openings so that the spring will, at all times, exert a substantialforce. It will be evident I from Figure l.that, when pawl 48 is moved off center; with respect-to pin 44, spring 56 will' actto pivot pawl' 48 so that oneend or theother of the pawl, depending upon the direction or the movementof pawl 48 01f cer ter, will be moved downwardly' into engagement with the ratchet wheel 36. Similarly the spring will urge of end 62 of spring 56.

The trailing end of pawl v 68-which is adapted to fit under the undercut portion 70 ofteeth 49 which prevents the spring 56 from raisingv pawl 48 out of engagement with a tooth 40. when the ratchet-pawl mechanism: is. functioning to prevent i re-.

winding of the reelas willbe-apparent from the; subsequent'description or theloperation of the reel. The leading end of pawl 48 isgpr'ovide'd with a squared face 72 to permit ready disengagement fromthe squared faces reel 2jthere canbe provideda pin 76.secured to bracket 42 and extending outwardly to a position whereit can engage 'pawl 48. .In theevent of the weakening of spring 56 so that it is unable to disengage the leading end of pawl from; a, ratchet teeth 40 during unreeling, the move- Patented Mar. 28, 1961 A cable 9 is shown par-.

48 is provided with a nose ment of pin 76 will act to cam pawl 48 to efiect the release of its leading end from a tooth 40.

I The, ratchet-pawl mechanism is protected by a cover plate 78 secured to ratchet wheel 36.

Operation The operation of the ratchet-pawl mechanism of the reel 2 will be made readily apparent by consideration of the schematic showings in Figures 3 through 14 studied in conjunction with Figures 1 and 2. It should be pointed out that the pawl 48 would not normally be in the position shown in Figures 1 and 2 which was selected to facilitate a clear showing in the drawings. To place, the reel 2 in operation, pawl 48 would first be manually shifted so that pin 44 was up against'either end of slot 50. This, of course, is accomplished during the manufacturing of the reel prior to the securing of cover plate 78 in position.

Referring now particularly to Figures 3 through 14, the dscription will be, facilitated by assuming the ratchetpawl' mechanism to be acting to prevent the reel from rewinding as shown in Figure 3. As seen in Figure 3, nose 68 is in engagement with undercut portion 70 of a tooth 40 and pin 44 is against the left-hand end of slot 50 as viewed in Figure 3. Spring 56 is attempting to pivot the leading end of pawl 48 downwardly so as to free nose 68 from tooth 40 but is prevented from doing so by the undercut portion 70 of tooth 40.

Bearing in mind that ratchet wheel 36 is fixed, that pin 44 is secured so as to move with drum 4 which contains cable 9 and that pawl 48 has a slot 50 permitting relative movement betweenpawl 48 and pin 44, if cable 9 is now pulled outwardly so as to unreel, which causes drum 4 to move clockwise as viewed in Figure 1, this will, in turn, (Figure 4) cause pin 44, spring 56 and pawl 48 to move clockwise as viewed in Figure 4 withdrawing the trailing end of pawl 48 from tooth 40 and permitting spring 56 to pivot the leading end of pawl 48 downwardly. As shown in Figures 5 and 6, further rotation in this direction causes face 72 on the leading end of pawl 48 to be forced into engagement with face 74 of the next tooth which arrests the motion of-pawl 48. Pin 44 continues to move clockwise as viewed in Figures 7 and 8 until it passes beyond the center line of pawl 48; permitting spring 56 to pivot pawl 48 so that the leading end is moved upwardly out of engagement with tooth 40, pin 44 moving to the.

end of slot 50.

As shown in Figures 9 and 10, as thecable 9 continues to be unreeled, the trailing end-of pawl 48 follows the contour of ratchet wheel 36 while theleading end is maintained' clear of the ratchet wheel to permit the free unwinding, of cable 9.

I It is now desired to stop unreeling cable 9 and yet retain substantially the sameamount of cableunreeled. The spring motor is permitted to reel in a short length of cable 9 moving drum 4 counterclockwise as viewed in Figure 1. In turn, as shown in Figure 11, pawl 48 and pin 44 are moved counterclockwise with spring 56 continuing to force the nose- 68 of pawl 48 downwardly, the nose 68, as shown in Figure 12, thus coming into engagement with the next tooth 40. As the reeling in continues, pin 44 continues to movecounterclockwise, as shown in Figures 13 and 14, until it abuts against the lefthand end of slot 50. It will now be. understood that the ratchet-pawl mechanismlhas'been returned to precisely the starting point shown in Figure 3, namely, where it prevents the spring motor from reeling in any more of cable 9.

If it is now desired to permit the spring motor to reel in all, or a substantial. portion of: cable 9, a length of cableis unreeled, to permit. pawl 48 .to bepositioned, as shown inv Figure ,4, Let, with nose68 having just, been freed from to oth 40. The spri-ng motor is th cn permitted to over and: reel, in before the position, of pawl 48' with respect topin 44jsjchangedjhytheengagernent.of theleath ing end of pawl 48 with the. nexttooth 40. Thus; with the pin '44 remaining in the position shown in Figure 4,

spring 56 continues to keep the nose 68 of latch 48 pivoted upwardly so that it will not engage the teeth 40. If it is then desired to reel out more cable, the sequence will be precisely as previously described in connection with Figures 5, 6 and 7 etc.

Figures 15 through 17 illustrate the action of pin 76 in the event of a weak spring 56. Figure 15 is comparable to Figure 6 and shows the reel going in the unreeling direction with the leading end of pawl 48 engaging the adjacent tooth 40. Figure 16 shows pin 44 having advanced clockwise well beyond the center line of pawl 48 with the spring 56 having failed ,to pivot pawl 48. Figure 17 shows pin 76 in engagement with the upper surface of pawl 48 and having cammed the leading end upwardly out of engagement with the adjacent tooth 40. As indicated pre viously, pin 76 is not necessary for the proper operation of the reel 2, It is desirable where in extended usage spring 56 might become weak or in the event that it is desired to use-, =at the outset, a; relatively weak spring 56.

Alternative embodiments Alternatively, the ratchet-pawl device in accordance with this invention is equally applicable to structures having relative linear movement.

As shownin Figure 18, a ratchet 102 is mounted on a window frame 104. Secured to a window sash 106 having a glass pane 108 is a pawl mechanism indicated at 110. Pawl mechanism 110 comprises a pawl 112 having a slot 114 mounted on aheaded pin 116 secured to sash 186. A, torsion spring 118 is secured on the center line of slot 114 at 120 and is alsosecured at 122 to a block 124 which, in turn, is secured to sash 106. The pawl mechanism 110 is protected by a casing 126. It: is believed that itwill be readily apparent that the operation of the-ratchet-pawl mechanism of Figure 18 is the same as that previously described for the mechanism of Figure l, the; essential difference being simply thatthe weight of the window sash 106 and pane 108 act as the biasing force, i.c., act to move the window downwardly.

A still further alternative embodiment is shown in Figures 2 0,, 21 and 2 2. This embodiment is suitable for a linear. application such as discussed in connection with Figures l8 and 19. Referring to Figure 20, a ratchet 130, which; can: be secured, for example, to a window frame, has teeth 132 with an undercut portion indicated at 134 atv theuppet; end of. each tooth. Cam portion 135 of ratchet 130 acts to cam pawl 14.0 outwardly as it is moved upwardly. A- pawl mechanism indicated. at 136 has a bracket 138, which, for example, can be secured to a.- window sash 139: --A pawl 140- has a slot 142 through which passes a headed pm 144 which is secured to bracket'138. A torsion spring 146 has one end secured to pawl 140m 148 on thecenter line of slot 142 and the otherend secured to bracket 138 as shown at 150. A slot 149 in bracket 138 provides-freedom of movement for the end of the spring 146 secured to the pawl. The lower end of pawl 140 has a nose 152 which is adapted to pass inside and engage the undercut portion 134 of tooth 132.

' Here, again, it is believed obvious that theratchetpawl mechanism of Figures 20-22 operates essentially a as described for the embodimentofFigure l, the major moved off center with respect to resilient means which will cause the pawl to rock clockwise or counterclocka wisedepending upon the direction of its displacement.

This is; accomplished through the use of a link in they acraass embodiment of Figures 23 through 25 rather than through the use of a slot.

As shown in Figures 23-25, a ratchet-pawl mechanism 160 has a ratchet wheel 162 with teeth 164 each having an undercut portion 166. Ratchet wheel 162 is secured against rotation by means not shown. A pawl 168 is pivotally secured to the lever 170 at 172 and lever 170 is, in turn, pivotally secured to a rotating disc 174 at 176. A torsion spring 178 has one end secured to pawl 168 at 180 and the other end secured to a block 182 at 184. Block 182 is secured to rotating disc 174. A pair of stop pins 186 and 188 are secured to disc 174 and extend outwardly to act as stops for lever 170. As shown in Fig. 23, when link 170 is centered between

stops

186 and 188 and when pawl 168 is centered with respect to lever 170, the ends of torsion spring 178 are secured in a plane passing through the pivot points of lever 170.

The embodiment of Figures 23-25 operates fundamentally the same as the embodiment of Figure 1. It will be appreciated that the position of the pawl 168 and lever 170 was selected for purposes of best illustrating the construction involved. However, the structure would never assume the position illustrated in Figures 23 and 24 in actual operation. The structure is shown in Figure 25 in a position to arrest counterclockwise movement of disc 174. In this position tooth 164 has arrested the movement of pawl 168 which, in turn, has caused lever 170 to be shifted to the right as viewed in Figure 25 against stop pin 188. Torsion spring 178 is also urging lever 170 to the right and further is attempting to pivot the right-hand end of pawl 168 downwardly which is prevented by engagement of the undercut portion 166 with the left-hand end of the pawl. A short rotation of disc 174 clockwise, as viewed in Figure 25, would release pawl 168 from tooth 164 and the pawl would then be pivoted so that it would be in a position permitting the free counterclockwise movement of disc 174. If a still further clockwise movement of disc 174 is carried out, the right-hand end of pawl 168 will be biased downwardly into engagement with the next tooth 164. This will result in the shifting of lever 170 to the left over center to a position where spring 178 will act to pivot pawl 168 counterclockwise as viewed in Figure 25 and free of tooth 164. With the pawl in this position, disc 174 can be freely rotated clockwise as much as is desired and, when its rotation is reversed, pawl 168 will return to the position shown in Figure 25.

It is not desired to be limted except as set forth in the following claims.

What is claimed is:

1. A stationary ratchet member in the form of a disc having formed in the outer periphery thereof at least one radially inwardly extending recess terminating at opposite ends in circumferentially widely spaced opposed ratchet tooth defining shoulders, a member revolvable about the axis of said ratchet member, a pawl having a length exceeding the distance between said shoulders and an elongated opening formed therein, a pivot element mounted upon said revolvable member and freely projected through said opening, said pawl being shiftable relative to said pivot element within the limits of said elongated opening, and being disposed radially outwardly from said ratchet member, and spring means reacting between said revolvable member and said pawl and adapted for pivoting said pawl for urging one end portion of said pawl into engagement with one of said shoulders when said pivot element is accommodated by one end portion of said elongated opening, and for urging the opposite end portion of said pawl into engagement with the other of said shoulders when said pivot element is accommodated by the other end portion of said elongated opening.

2. A stationary ratchet member in the form of a disc having formed in the outer periphery thereof at least one radially inwardly extending recess terminating at opposite ends in circumferentially widely spaced opposed ratchet tooth defining shoulders, one of which shoulders is undercut, a member revolvable about the axis of said ratchet member, a pawl having a length exceeding the distance between said shoulders and an elongated opening formed therein, a pivot element mounted upon said revolvaole member and freely projected through said opening, said pawl being shiftable relative to said pivot element within the limits of said elongated opening, .and being disposed radially outwardly from said ratchet mem* her, and a torsion spring reacting between said revolvable member and said pawl and adapted for pivoting said pawl for urging one end portion of said pawl into engagement with the undercut shoulder aforesaid when said pivot element is accommodated by one end portion of said elongated opening, and for urging the opposite end portion of said pawl into engagement with the other of said shoulders when said pivot element is accommodated by the other end portion of said elongated opening, the undercut shoulder aforesaid being operative for releasably holding the end portion of the pawl engaged therewith against the influence of said torsion spring when said pivot element is accommodated by the firstrnentioned end portion of said elongated opening.

3. A stationary disc having formed in the outer periphe ery thereof at least one radially inwardly extending recess terminating at opposite ends in circumferentially widely spaced opposed ratchet tooth defining shoulders,- a member revolvable about the axis of said disc, a pawl member having a lentgh exceeding the distance between said shoulders, a pivot element mounted upon one of said members and freely projected through an elongated opening formed in the other of said members, said pawl being shiftable relative to said revolvable member within the limits of movement of said pivot element in said elongated opening, and being disposedradially outwardly from said ratchet member, and spring means reacting between said revolvab le and pawl members and adapted for pivoting said pawl for urging one end portion of said pawl into engagement with one of said shoulders when said pivot element is accommodated by one end portion of said elongated opening, and for urging the opposite end portion of said pawl into engagement with the other of said shoulders when said pivot element is accommodated by the other end portion of said elon gated opening.

Reterences Cited in the file of this patent UNITED STATES PATENTS 1,112,771 Cornwell Oct. 6, 1914 1,445,271 Gent Feb. 13, 1923 1,675,579 'Seng July 3, 1928 2,270,283 Ewald Jan. 20, 1942 2,741,930 Montooth et al. Apr. 17, 1956 2,772,576 Ross Dec. 4, 1956 FOREIGN PATENTS 249,695 Switzerland May 18, 1948