US1239917A - Pawl-and-ratchet mechanism. - Google Patents

Description

H. N. JOSLEYN.

PAWL AND RATCHET MECHANISM.

APPIICATION FILED JUNE 23.1915- Pzmnted @apt. 11., 1917.

UNITED %TATE@ PAT t1 HUBBARD N. JOSLEYN, OF SYRACUSE, YORK, ASSIGNOR TO REMINGTON TYPE- WRITER COMPANY, OF ILION, NEW YORK, A CORPORATION OF NEW YORK.

' PAWL-AND-RATCHET MECHANISM.

Specification of Letters Patent.

Patented Sept. Ml, 19117.

Application filed June 23, 1915. Serial No. 35,837.

To all whom it may concern:

Be it known that I, HUBBARD N. JosLEYN citizen of the United States, and resident 0 Syracuse, in the county of Onondaga and State of New York, have invented certain new and useful Improvements in Pawl-andinvention has for its object to provide automatic means for disengaging or separating the pawl and ratchet devices which connect two moving or rotating parts or elements so that when one of said elements turns in one direction, the pawl and ratchet devices connect the other element with it but when the direction of movement or rotation is reversed or changed the pawl and ratchet devices are automatically disconnected so that instead of the pawl clicking idly and noisily over the teeth of the ratchet device it is entirely separated from the ratchet device, thus eliminating noise and friction.

To the above and other ends my present invention consists in the features of con' 'machine and the pawl and ratchet devices are those connecting the escapement wheel with the shaft on which it is mounted. In carrying out the invention I mount on the ratchet wheel which is fixed as is usual tothe rear face of the escapement wheel, a circular piece of spring metal which through its inherent tendency to close, grips the ends of the ratchet wheel teeth with suiiicient friction to be carried around with said ratchet wheel when the carriage is moved in letter space direction. The ends of the spring piece are separated so that there is room between them for the pawl to engage with the teeth of the ratchet wheel, the pawl being spring pressed toward the ratchet wheel as is usual and operating in the usual way during movements of the carriage in printing direction to connect the shaft with the escapement wheel. As soon, however, as the direction of rotation of the shaft is reversed, which occurs when the carriage is returned toward the right, the pawl starts to move independently of the ratchet wheel which together with the spring piece remains motionles The end of this spring piece underlyiifg the pawl operates as a cam, causing the awl to disengage from the ratchet wheel tooti and swing or move outward against the constantly exerted and increasing pressure of its own spring. As soon as this pressure overcomes the friction exerted between the spring piece and the ratchet wheel or as soon as the swing of the pawl is otherwise arrested, it will operate to overcome the friction of the spring piece on the ratchet wheel and will force said spring piece to turn or rotate on the ratchet wheel as the return movement of the carriage continues. After the carriage is arrested and as soon as movement in printing direction again begins, the pawl will drop automatically into engagement with the ratchet wheel, again connecting the shaft with the escapement wheel. It will be seen that the invention may be carried out by applying a single device, viz., the circular sprin metal piece, to the usual construction of the escapement mechanism without in any way altering any of the parts of the latter. The invention will be more particularly described in connection with the accompanying drawings, wherein Figure 1 is a front to rear vertical sectional view of a Monarch typewriting machine embodying my invention, only so much of the machine being shown as is necessary to a complete understanding of said invention.

Fig. 2 is a vertical sectional View taken on a plane indicated by the dotted line 00-00 in Fig. 1 and looking forward.

Fig. 3 is a vertical sectional view taken on a plane indicated by the dotted line y in Fig. 2 and looking in the direction of the arrow.

Fig. 4 is a view corresponding to Fig. 2 but omitting the dog rocker and showing some of the parts indifferent relations from those in which they appear in Fig. 2.

Fig. 5 is a detail view illustrating some of the parts shown in Figs. 2 and 4: in different relations from those shown in the last named figures. As illustrated in the drawings the main frame of the machine comprises a base 1, posts 2 and a top plate 3 above which are oppositely grooved fixed track-ways A that llll cotiperate through anti-friction balls 5 with the slide bar of a carriage 6 on which is mounted a platen 7 Cooperative with the base. Comprised in said frame is a rear wardly extending arm 16 that is connected by a link or device 17 with a dog rocker 18 mounted on stationary pivots 19 (Fig. 2) and having pivoted near its upperend two escapement dogs 20 and 21 that cooperatewith a toothed escapement' wheel 22. Rigid with the escapement wheel is an elongated hub 23 (Fig. 3) that bears in a bracket 24: fixed to the top plate. The hub is bored out to fit over a shaft 25 which has fixed to its forward end a feed pinion 26 that normally meshes with a feed rack 27 mounted on arms 28 pivoted to the carriage 6. Said carriage is constantly urged toward the left by a motor or sprin drum 29 that is connected to the carriage by a strap 30.

The movable or rotatable elements, 2'. e., the escapement wheel 22 and its shaft 25, are disconnectibly connected by connecting devices through which one element is moved or driven by the other. Said devices comprise a ratchet wheel 31 which is fixed by rivets or otherwise to the rear face of the esca ement wheel 22. Engageable with the ratciiet wheel or device is a pawl device 32 which is pivoted on a pin 33 fixed within a cap or housing 34: Said cap has a hub 35 which is fixed by a set screw 36 to the rear end of the shaft 25. The cap covers or houses the pawl andratchet driving devices and provides for the pawl a support which is rigid with the shaft 25. The outer face of the cap 34 may be provided with teeth 37 with which cooperate back spacing devices (not shown). Fixed to the inner circular wall of the cap as by arivet 38 is a leaf spring 39 the free end whereof cooperates with the pawl 32 and constantly presses it toward the ratchet wheel 31. Normally the ratchet wheel is engaged by the pawl as shown in Fig. 2 so that during leftward or letter spacing movements of the carriage the motion is transmitted through the rack 27 to the feed pinion 26, the latter being caused to rotate in the direction of the arrow in Fig. 2. This rotarymotion is transmitted through the shaft 25 to the pawl 32 and from it through the ratchet wheel 31 to the escapement wheel 22 so that when the escapement dogs 20 and 21 cooperate with it during the printing operations in the usual way the escapement wheel arrow and permits letter space advance movements of the carriage. The construction hereinbefore described is essentially the same as that found in the ordinary Monarch machine.

Heretofore when the carriage has been returned toward th right, the pawl 32 has revolved backward about the axis of the shaft 25, as said shaft has rotated in a direction opposite to the arrow in Fig. 2, and as a result the pawl-has clicked idly over the teeth of the ratchet wheel 31 which with the escapement wheel has remained stationary. This results in noise and friction. Primarly to do away with the noise I provide means comprising a device or curved piece of spring metal 40 which surrounds the ratchet wheel 31 and bears lightly or against the ends of the teeth thereof but with sutlicient friction that when not obstructed the spring device will be carried around with and on said ratchet wheel as it rotates. The spring device or clip is carried or supported wholly by the ratchet wheel which in turn is fixed to the escapement wheel or element 22. The ends of the spring device are separated, leaving a space indicated in Fig. 4 by the numeral 41 through which the tooth of the pawl may pass to cooperate with the ratchet wheel. As viewed from the rear the left-hand free end of the spring 40 is turned out slightly and underlies the pawl 32 between its tooth end and its pivot. This sprlng end is contiguous to the under face of the pawl when the pawl is engaged with the ratchet wheel as shown in Fig. 2. The opposite end of the spring device is curved or bent outward away from the ratchet teeth so as not to catch on them. When the return movement of the carriage begins, parts are as in Fig. 2, the pawl will, as its support begins to rotate in a direction opposite to the arrow, move bodily downward and will engage with the left end of the spring 40 which at this time is stationary. The result is that the spring will act somewhat like a cam and will automatically cause the pawl to turn on its pivot 33 overcoming the spring 39 and rendering the pawl inoperative on the ratchet wheel. This pivotal movement of the pawl will continue as its bodily movement around the axis 25 continues and will not cease until the spring 39 has been flexed to such an extent that it will become strong enough to overcome the friction of the automatic means or sprin 40 against the ratchet wheel 31. When this occurs, the parts will be in the position shown in Fig. 4. Subsequently as the pawl support or cap 34 contmues to rotate the pawl will move bodily but will no longer turn on its own axis and consequently the curved under edge of its tooth acting against the free left-hand end of the spring 40 will force the spring to turn or rotate on and relatively to the ratchet wheel 31. This will be clear from a comparison of Figs. 4 and 5. It will be apparent that after the pawl has been swung automatically to the inoperative or Fig. '4. position, said pawl will, during the subsequent rightward movement of the carriage, be entirely separated from the ratchet wheel. Assuming that when the carriage is arrested at the end of its return or rightward movement the parts will be in the positions shown in Fig. 5, then when the next leftward movement of the carriage begins the pawl will be in position to be forced by its spring 39 int-o engagement with the ratchet wheel 31, only a slight movement of the shaft 25 being necessary to carry the pawl forward far enough past the end of the spring 40 to permit of this.

It will be observed that by the present invention there are provided two rotatableelements, each comprising a rotatable member and also a connecting device; that the members aforesaid in the present instance are the escapement wheel 22 and its shaft 25 carrying the feed pinion 26; that the devices aforesaid are in the present instance the pawl and the ratchet; that said elements are connected during rotation in one direction; that traveling means, in the present instance the part 40, is provided for automatically disconnecting said devices when the direction of rotation is reversed, said means being rotatively supported on one of said rotatable elements alone independently of the other of said elements, the means in the present case being supported on the ratchet device, which together with the escapement wheel 22 comprise one of said rotatable elements.

As a result of the entire separation of the pawl from the ratchet wheel during the carriage return movement the usual disagreeable noise due to the pawl clicking and scraping idly over the successive ratchet teeth will be entirely eliminated as will also be the sliding friction. If my present invention be combined with an anti-noise device for the spring drum disclosed and claimed in my co-pending application, Serial No. 35,838, filed June 23, 1915, it will be found that the greater part of the noise incident to the return movements of the typewriter carriage has been done away with.

It will be understood that while my in vention has been shown applied to the pawl and ratchet connections between parts of the escapement mechanism, it is, of course, applicable to other connections in typewriting and other machines, and it will also be understood that while my invention is shown applied to the Monarch typewriting machine it may readily be adapted to other styles of writing and other machines, and that various changes may be made without departing from my invention.

What I claim as new and desire to secure by Letters Patent, is

1. In mechanism of the character described, two disconnectible rotatable elements provided with devices effective to connect said elementsduring rotation in one direction, in combination with traveling means for automatically disconnecting said devices when the direction of rotation is reversed, said traveling means being rotatively supported on one of said rotatable elements.

2. In mechanism of the character described, the combination of two rotating elements, pawl and ratchet devices for connecting said elements, a spring tending constantly to maintain said pawl and ratchet devices in engagement,and a cam device independent of said pawl device and mounted'on and partly surrounding and frictionally engaging said ratchet device, so as to be rotatable with said ratchet device, said cam device operating on said pawl device to disengage it from said ratchet device when the direction of rotation of one of said elements is reversed.

3. In mechanism of the character described, the combination of two rotatable elements, pawl and ratchet devices for connecting said elements, a spring tending constantly to maintain said pawl and ratchet devices in engagement, and a C-shaped spring surrounding and frictionally gripping said ratchet device, one end of said 0- shaped spring, when the direction of rotation of said elements is reversed, engaging said pawl device and throwing it out of the ratchet device, after which during further movements of rotation said pawl device forces said C-shaped spring ahead of it.

4. In mechanism of the character described, the combination of a wheel ashaft on which said wheel is mounted, disconnect-- ible pawl and ratchet devices for connecting said wheel with said shaft, and a spring clip mounted on the ratchet device and effective to throw said pawl out of engagement therewith.

5. In mechanism of the character described, the combination of a wheel, a shaft, a ratchet wheel connected with said wheel, a pawl pivotally mounted and supported from said shaft, a spring for pressing said pawl into engagement with said ratchet wheel, and a device partly surrounding and frictionally engaging said ratchet wheel, said device operating on said pawl to disengage it from said ratchet wheel when the shaft is turned backward.

6. In mechanism of the character described, the combination of a wheel, a shaft,

a ratchet wheel connected with said wheel,

a pawl pivotally mounted and supported from said shaft, a spring for pressing said pawl into engagement with said ratchet wheel, and a C-shaped spring surrounding and frictionally gripping said ratchet wheel, one end of said C-shaped spring, when the direction of rotation of the shaft is reversed, engaging said pawl and throwing it out of the ratchet wheel after which said pawl forces said C-shaped spring ahead of it.

7. In mechanism of the character described, the combination of a wheel, a shaft supporting the same, a ratchet wheel fixedly vconnected with said first recited wheel, a

housing for said ratchet wheel fixed to said shaft, a pawl pivoted within and to said housing, a spring constantly pressing said pawl toward said ratchet wheel, and a second spring partly surrounding said ratchetwheel and frictionally engaging therewith,

one end of said second spring acting as a cam to force said pawl out of engagement I with said ratchet wheel when the direction of rotation of said shaft is reversed.

8. The combination of a driving member, a pawl pivoted to rotate therewith, a driven member including a ratchet wheel with which said pawl normally engages, and an interposed device rotating normally with said ratchet wheel and adapted on reversal of the movement of the driving member to disengage the pawl from the ratchet wheel, and adapted also to be moved by said pawl in reverse direction while said ratchet wheel direction, in combination with traveling means for automatically disconnecting said devices when the direction of rotation is reversed, said traveling means being under the control of said devices and directly supported by one of them alone.

Signed at Syracuse, in the county of Onondaga and State of New York, this 21st day of June, A. D. 1915.

' HUBBARD N. J OSLEYN.

Witnesses:

RAYMOND L. WILLIAMS,

CHAS. PRA'I'I.

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