US3311213A

US3311213A - Latch devices

Info

Publication number: US3311213A
Authority: US
Inventors: Alfred E Amos
Original assignee: Sperry Rand Corp
Current assignee: Sperry Corp
Priority date: 1964-02-28
Filing date: 1964-02-28
Publication date: 1967-03-28
Anticipated expiration: 1984-03-28

Description

March 28, 1967 mos 3,311,213

LATCH DEVICES Filed Feb. 28, 1964 2 Sheets-Sheet l I NVEN TOR. flz Peso E. 4/ 405 4 rroeuzsy A- E. AMOS LATCH DEVICES March 28, 1967 2 Sheets-Sheet 2 Filed Feb. 28, 1964 6? "Mill! INVENTOR. 40-250 E. ml a United States Patent 3,311,213 LATCH DEVICES Alfred E. Amos, Fair-field, Conn, assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed Feb. 28, 1964, Ser. No. 348,216 7 Claims. (Cl. 197186) The present invention relates to new and useful improvements in latch devices, and more particularly to latch devices for pivotable levers of the type employed in typewriting machines.

In typewriting machines, as for example, portable typewriters and carrying cases therefor, pivotally mounted elements or levers are used to perform a variety of functions. Some of these levers are mounted for movement between operative and inoperative positions about their pivots, and means are required to maintain these levers in operative position during use. For example, it is the usual practice to provide a detachably hinged cover member over the typewriter when the latter is not in use or when the machine is to be transported. These covers are provided with various locking devices which, in some instances, include space-d levers pivotally mounted on the cover and which levers are swung into locked engagement with portions of the typewriter to secure the cover thereto.

Another type pivotable lever employed in portable typewriters is the line spacing lever, which is mounted on the typewriter adjacent the platen, and which lever is periodically rocked by the operator in a well-known manner about a vertical axis to rotate the platen a desired increment. These line spacing levers are also pivoted for movement about a horizontal axis to allow the lever to be moved to a lower inoperative or folded position to permit the casing cover to be placed over and secured to the typewriter.

In use of the mentioned mechanisms, problems have arisen in providing adequate and economical latch means to insure that these pivotable levers are not accidentally released from operative to inoperative positions during use. In the use of the casing locking levers, as mentioned, means must be provided to prevent the levers from releasing to inoperative position when the machine is transported, to prevent the cover from opening and subjecting the typewriter to damage. In the use of the line spacing levers, it must be assured that the lever will not be accidentally pivoted on its horizontal axis to inoperative position while the operator is rocking the lever during a line spacing operation.

The object of the present invention is to provide a novel latch device for maintaining a pivotable lever in operative position.

Another object is to provide a novel latch mechanism for maintaining a pivotable lever in operative position, and which latch mechanism includes means to prevent accidental release of the lever from an operative to an inoperative position.

Another object is to provide a novel latch mechanism for pivotable levers of the type used in typewriting machines and covers therefor, and which latch mechanism comprises relatively few parts and provides a positive latching of the levers in operative position thereof without interfering with the normal operation of the levers.

A further object is to provide a novel latch device of relatively few parts which is adapted for use with line spacing levers and cover locking levers of typewriters, and which device is provided with positive means for preventing accidental release of these levers from operative position.

The present invention contemplates novel means for maintaining a pivotable lever in an operative position on its pivot against accidental release to inoperative position. According to the present invention, a lever is pivotably mounted on a fixed support and is movable about its pivot to spaced operative and inoperative positions. A latch mechanism is provided for the lever and which mechanism includes a slidable latch plate on one face of the lever with an operating button therefor on the opposite face. Spring means are provided to maintain the latch plate in engagement with stop means provided on the fixed support when the lever is in operative position. Sliding movement of the button effects release of the latch plate from the stop means allowing the lever to move to inoperative position. In addition, the button member carries a shouldered lug member, movable upon rotation of the button member, in one direction to prevent accidental release of the latch plate. Rotation of the button in the opposite direction allows for unobstructed movement thereof to release the latch plate and lever to inoperative position.

The above and other objects and advantages of the present invention will appear more fully hereinafter from a consideration of the detailed description which follows,

.taken together with the accompanying drawings wherein two embodiments of the invention are illustrated.

In the drawings:

FIG. 1 is a perspective view of a portable typewriter and cover thereof in which is incorporated the present invention with a portion of the cover broken away to show the typewriters line spacing lever in inoperative lowered position;

FIG. 2 is a sectional view taken on the line 2-2 of FIG. 3;

FIG. 3 is a fragmentary elevational view of the cover locking lever as seen at the left in FIG. 1 with portion of the lever broken away to show the latch mechanism therefor;

FIG. 4 is a view similar to FIG. 3 wherein the latch mechanism operating button has been rotated prior to release of the locking lever;

FIG. 5 is an exploded perspective view of the parts and mounting for the casing locking lever latch mechanism;

FIG. 6 is an enlarged perspective view of the line spacing lever of FIG. 1 moved to upper operative position and which lever incorporates another embodiment of the present invention;

FIG. 7 is a fragmentary plan view of the mounting of the line spacing lever with portions of the lever broken away to show the latching mechanism therefor;

FIG. 8 is a sectional view taken on the line 88 of FIG. 7;

FIG. 9 is an exploded perspective view of the principal parts of the latch mechanism of FIG. 7;

FIG. 10 is a side fragmentary elevational View partly in cross-section of the line spacing lever and latch mechanism therefor in released inoperative position.

Referring now to the drawings for a more detailed description of the present invention and, more particularly, to FIGS. 1 to 5 inclusive, wherein one preferred embodiment is clearly illustrated, a portable typewriting machine and dome-shaped cover therefor are generally indicated by the

reference numerals

16 and 11 respectively. Cover 11 (FIG. 1) is fitted over and encases typewriter 10 in a usual manner, and is provided with a separable hinge connection (not shown) at the rear of typewriter 10 in a manner well known in the art, whereby cover 11 is read ily removable from typewriter 10 when desired.

As shown in FIG. 1, spaced locking mechanisms 14 and 15, respectively, are provided on front wall 16 of cover 11 at each side of a carrying handle 18 to lock cover 11 to typewriter 10. Latch mechanisms 14 and 15 are identical at each side of handle 18, and the description hereinafter set forth thereof is to only the locking mechanism 14 at the left in FIG. 1. It is to be further understood that the present invention, which i to be hereinafter described, is not limited to the particular typewriter or cover shown, the drawings having been simplified to show only such conventional parts of typewriter and cover 11 as necessary for a clear understanding of the present invention.

Cover locking mechanism 14 includes an elognated locking lever having a hook-shaped end portion 21 in engagement with the lower edge of cover front wall 16 and a lip 22 formed on the upper edge of typewriter front wall 23 (FIGS. 1 and 2). Means are provided for pivotally mounting the other end of locking lever 2i) to front wall 16 of cover 11 within a recessed portion 25 of handle plate 26; and which means include an L-shaped supporting bracket member 28 (FIGS. 2 and 5). Bracket 28 comprises a leg portion 29 secured to cover 11 in any suitable manner (not shown) and an outwardly projecting foot portion 36. Foot portion 36 is provided with

spaced stop lips

31 and 32 bent at right angles in opposite directions away from foot 36 for purposes to be hereinafter explained.

Spaced ear projections

33 and 34 are provided at opposite side edges of bracket leg 29 and extend outwardly away from cover 11. Lever 20 is provided with spaced sidewalls 35 fitted over bracket 28 and pivotally mounted thereon by a pivot pin 36, which is rotatably disposed in spaced apertures 37 of bracket cars 33 and 34 (FIG. 5), and which pin 36 has opposite ends secured to lever sidewalls 35.

Latch means are provided to maintain locking lever 20 in operative position with hook portion 21 in engagement with lip 22 of typewriter 10 (FIGS. 1 and 2), and which means include a release button 38 and a latch plate 39 arranged on the opposite faces of lever 20. Button 38 is slidably mounted on the front face of lever 20 and is provided with a stub shaft 49 which extends through an elongated slot 41 in locking lever 20 and then through an aperture 42 in latch plate 39, and which plate 39 is slidably disposed on the other face of locking lever 20. Latch plate 39 is provided with a step portion 43 in engagement with stop lip 32 of bracket 28. In addition, a rotatable lug member 44 is secured to the end of shaft and, as seen in FIGS. 3 and 5, is provided with a shoulder portion 45 abutting against an inturned flanged portion 46 on bracket ear 34. Resilient means are provided to maintain step 43 of latch plate 39 in engagement with stop lip 32, and which means include a spring member 47 having one end attached to shoulder 45 of lug 44 with the opposite end fixed to foot 30 of supporting bracket 28. Spring 47 urges button 38 and latch plate 39 in the direction designated by the arrow A in FIG. 3, whereby step portion 43 is maintained in engagement with stop lip 32. In addition, spring 47 urges locking lever 20 in a counterclockwise direction (FIG. 2) with the said counterclockwise movement prevented by the engagement of step portion 43 with stop lip 32.

From the above description, it will be apparent that locking lever 29 is securely held in operative position by latch plate 39. Accidental movement of step portion 43 of latch plate 39 out of engagement with stop lip 32 is prevented by shoulder 45 of lug 44, which abuts against flanged portion 46 of ear 34. If it is desired to release locking lever 20 from operative position to inoperative position, one rotates button 38 in the direction designated by arrow B in FIG. 3, moving shoulder 45 of lug member 44 clear of flanged portion 46 to the position shown in FIG. 4 without effect on latch plate 39. Button 33 is then moved in the direction designated by arrow C (FIG. 4) moving latch plate 39 and permitting step portion 43 to move clear of stop lip 32. As step portion 43 is moved clear of lip 32, spring 47 operates to pivot locking lever 20 counterclockwise (FIG. 2) to an inoperative position shown in broken lines in FIG. 2. As locking lever 20 reaches inoperative position, an end lip portion 48 of latch plate 39 engages lip 32 preventing further movement of locking lever 29.

In order to restore locking lever 20 to engaged position with typewriter 10, the locking lever 29 is pivoted clockwise from the position shown in broken lines in IG. 2, to re-engage hook portion 21 with lip 22 of typewriter 19 with the rear face of lever 20 abutting lip 31 of bracket 28. As hook portion 21 thus re-engages lip 22, latch plate 39 is cammed against the edge of stop lip 32 moving step portion 43 of latch plate 39 into re-engagement with lip 32. In order to prevent accidental release of latch plate 39, operating button 38 is rotated to move lug 44 into abutment with flange 46 of bracket ear 34 (FIG. 3) to thereby obstruct movement of latch plate 39 to an unlatched position.

In FIGS. 6 through 9, inclusive, another embodiment of the present invention is disclosed in which the novel latch mechanism is adapted for use with a line spacing lever St) for typewriter 10. Line spacing lever 50 is adapted in a well-known manner to line space a rotat able platen 51 (FIG. 6) by rotating platen 51 a predeter mined increment through operation of a ratchet and pawl mechanism generally indicated by the reference numeral 52 in a manner well known in the art through the rocking of line spacing lever 50 about a vertical axis designated by the line V--V in FIG. 6. Line spacing lever 50 is further pivotable about a horizontal axis designated by the line H-H in FIG. 6 in a manner to be hereinafter fully described to lie adjacent a sidewall of typewriter 10 (FIG. 1) whereby cover 11 is readily mounted over the machine. The present invention contemplates means to secure the line spacing lever 50 in operative position and prevent accidental release thereof to the lower inoperative position (FIGS. 1 and 10).

To this end, a supporting bracket 54 is mounted on typewriter 10 adjacent platen 51 by means such as screw and nut arrangement '56 (FIG. 8) with bracket 54 freely rotatable about the unthreaded portion of the screw. Bracket 54 is provided with spaced upright cars 58 (FIG. 9), each of which ears 53 is provided with a pointed stop projection 59 extending outwardly from a side edge of cars 58. Spaced forward sidewalls 60 and 61 of lever 50 (FIG. 7) are mounted over bracket 54 and secured thereto by a pivot pin 62. Pivot pin 62 is ro-' tatably disposed in spaced aperture 63 of bracket ears 58 with the opposite ends of pivot pin62 secured to spaced sidewalls 60-61 of lever 50. Rocking movement of lever 50 about vertical axis V-V (FIG. 6) causes bracket 54 to pivot about screw 56 to effect operation of the ratchet and pawl mechanism 52 to line space platen 51 in a manner well known in the art.

A latch mechanism is provided to maintain lever 50 in its operative position against accidental release to lower position (FIG. 10), and which latch mechanism includes a release button 64 and a T-shaped latch plate 65 ar ranged respectively on opposite faces of the forward portion (FIG. 6) of line spacing lever 50. Button 64 is slidably disposed on the outer face of lever 50, and is provided with a stub shaft 67 which extends through an elongated slot 68 in lever 50, and then through an aperture 69 in latch plate 65 slidably disposed on the under face of lever 50. In addition, a rotatable lug member 71 is secured to the end of shaft 67 and is provided with a shoulder portion 72 (FIGS. 7 and 8) in engagement with an inturned flange 73 on lever sidewall 61.

As seen in FIGS. 8, 9 and 10, the T-shaped latch plate 65 is provided with spaced leg portions 75 depending from the spaced side edges thereof. Legs 75 are provided with surfaces designated x and y, with surface x of each leg 75 seated on the upper edge of a stop projection 59 of bracket 54. A spring 77 is provided to maintain legs 75 in latched engagement on projections 59. Spring 77 has one end secured to shoulder 72 of lug member 71 with the opposite end of spring 77 fixed to pivot pin 62, whereby latch plate 65 and operating button 64 are urged in the direction designated by the arrow F in FIG. 8 to prevent accidental disengagement of legs 75 from stop projections 59 during use of lever 50.

If it is desired to release line spacing lever 5-9 to lower position, button 64 is rotated clockwise (FIG. 7) moving shoulder 72 of lug member 71 clear of flange 73 on lever sidewall 61. As lug 71 is thus moved clear of flange 73, operating button 64 is then moved in the direction designated by arrow G against the bias of spring 77, moving latch plate 65 to release legs 75 from projections 59 and allowing lever 50 to move and pivot about horizontal axis HH (FIG. 6) to inoperative position as shown in FIG. 10. As lever 50 moves to inoperative position, surfaces x of spaced legs 75 rides off projec tions 59 and allowing lever 50 to move and pivot about of projections 59 (FIG.

In order to restore lever 50 to upper operative latched position, an operator need only lift lever 59, whereby surfaces y of spaced legs 75 ride along the bottom edges of spaced projections 59. As lever 50 assumes operative position, surfaces x of legs 75 are moved into position on top of projections 59 under the urging of spring 77, relatching the lever 50 in operative position. Accidental release of latch plate 65 is then prevented by rotating button 64 to move shoulder 72 of lug 71 into abutment with flange 73 (FIG. 7) to obstruct movement of latch plate 65 in the direction of arrow G (FIG. 8).

It will be apparent from the foregoing description that the novel latching device of the present invention has many advantages in use. One advantage is that positive means are provided to maintain a pivotable lever in operative position against accidental release to inoperative position. Further, the latch mechanism requires rela tively few and economical parts and requires a relatively small area of operation, whereby normal operation of the levers is not hindered.

It is to be expressly understood that the present invention is not limited to the embodiments illustrated and described. Various changes can be made in the design and arrangement of parts without departing from the spirit and scope of the invention, as the same will now be understood by those skilled in the alt.

What is claimed is:

1. A latch device of the class described comprising (a) a support member,

(b) a lever ivotally mount-ed on said support member for movement between operative and inoperative positions,

(c) a latch plate slidably mounted for movement with movement of said lever,

(d) stop means for said latch plate,

(e) spring means urging said latch plate into engagement with said stop means to maintain said lever in operative position,

(f) means for releasing said latch plate to provide for movement of said latch plate out of engagement with said stop means to allow said lever to move to said inoperative position,

(g) means for connecting said release means to said latch plate,

(h) a lug member operably associated with said connecting means, and

(i) a flange on said support member,

(j) said lug member being movable in one direction by said release means into engagement with said flange in said operative position of said latch plate to prevent slidable movement of said release means to release said latch plate.

2. A latch device of the class described, comprising (a) a supporting bracket member,

(b) a lever pivotally mounted on said bracket member for movement a predetermined distance between operative and inoperative positions,

(c) spring means urging said lever about said pivot to said inoperative position,

(d) stop means on said supporting bracket member,

(e) a latch plate slidably mounted on one face of said lever for movement with movement of said lever,

(f) said latch plate having spaced first and second latch portions provided on one end of said latch plate,

(g) said spring means maintaining said first latch portion of said latch plate in engagement with said stop means on said bracket to maintain said lever in 0perative position, and

(h) means on said lever operable to effect movement of said first latch portion of said latch plate out of engagement with said stop means to allow said spring means to move said lever said predetermined distance about said pivot connection to said inoperative position, whereat said second latch portion of said latch plate engages said stop means to prevent movement of said lever beyond said inoperative position.

3. A latch device of the class described, comprising (a) a fixed support member,

(b) a lever pivotally mounted on said support member for movement a predetermined distance between operative and inoperative positions,

(c) a latch plate slidably mounted on one face of said lever,

(d) stop means formed on said support member,

(e) spring means maintaining said latch plate in engagement with said stop means to maintain said lever in said operative position,

(if) means for releasing said latch plate to eflect movement of said lever said predetermined distance to said inoperative position,

(g) said release means including a rotatable button slidably mounted on the other face of said lever,

(h) means connecting said button to said latch plate,

(i) a lug member carried by said connecting means,

and

(j) a flange on said supporting member,

(k) said lug member being movable in one direction by said button into engagement with said flange in said latched position of said latch plate to prevent slidable movement of said button to release said latch plate.

4. In a typewriter having a rotatable platen and means for rotating said platen,

(a) a support member movably mounted on said typewriter adjacent said platen,

(b) a line spacing lever mounted on said support member for movement with said support member about a vertical axis to eflect operation of said platen rotating means,

(c) pivot means on said support member to allow for movement of said line spacing lever about a horizontal axis from said operative position to an inoperative position,

(d) latch means for maintaining said line spacing lever in said operative position,

(c) said latch means including a latch plate mounted for movement with movement of said line spacing lever,

(f) stop means for said latch plate,

(g) spring means urging said latch plate into engagement with said stop means to maintain said line spacing lever in operative position for movement about said vertical axis, and

(h) release means carried by said line spacing lever operable to provide for movement of said latch plate out of engagement with said stop means to allow said lever to move on said pivot means about said horizontal axis to said inoperative position,

(i) and means operable by said release means movable into and from abutting engagement with a part on said lever for blocking and freeing said release means.

5. In a typewriter having a rotatable platen and means for rotating said platen,

(a) a support member movably mounted on said typewriter adjacent said platen,

(b) a line spacing lever mounted on said support member for movement with said support member about a vertical axis to eifeet operation of said platen rotating means,

() pivot means on said support member to allow for movement of said line spacing lever about a horizontal axis from said operative position to an inoperative position,

(d) a latch plate carried by said line spacing lever,

(e) stop means formed on said support member,

(f) a leg on said latch plate,

(g) spring means maintaining said leg in engagement with said stop means on said support member to maintain said line spacing lever in operative position, and

(h) means for releasing said leg from said stop means to effect movement of said line spacing lever on said pivot means about said horizontal axis to said inoperative position,

, (i) said release means including button means on said line spacing lever operable to move said latch plate leg out of engagement with said stop means,

(j) and means operable by said release means movable into and from abutting engagement with a part on said lever for blocking and freeing said release means.

6. In a typewriter having a rotatable platen and means for rotating said platen,

(-a) a support member mounted on said typewriter adjacent said platen,

(b) a line spacing lever mounted on said support member for movement with said support member about a vertical axis to effect operation of said platen rotating means,

"(0) pivot means on said support member to allow for movement of said line spacing lever about a horizontal axis from said operative position to an inoperative position,

(d) latch means for maintaining said line spacing lever in said operative position, 7

(e) said latch means including a slidable latch plate carried by said line spacing lever for movement with movement of said line spacing lever,

(f) stop means for said latch plate,

(g) spring means maintaining said latch plate in engagement with said stop means to maintain said line spacing lever in said operative position, and

(h) means for releasing said latch plate to effect move- .ment of said line spacing lever on said pivot means about said horizontal axis to said inoperative position,

(i) said release means including a rotatable button slidably mounted on the face of said line spacing lever,

( j) means connecting said button to said latch plate,

(k) a lug member carried by said connecting means,

and

' (l) -a flange portion on said line spacing lever,

(m) said lug member being movable into engagement with said flanged portion upon rotation of said button in one direction in said operative position of said line spacing lever to prevent operation of said button to release said latch plate from said step means.

7. In a typewriter having a cover and a pivotable locking lever for securing said cover to said typewriter,

(a) a bracketon said cover member,

(b) said locking lever pivotally mounted on said bracket member for movement a predetermined distance between locked engagement with said typewriter to an unlocked position,

(c) a latch plate slidably mounted on said locking lever for movement with said locking lever,

((1) stop means for said latch plate,

(e) spring means urging said latch plate into engagement with said stop means to maintain said locking lever in said locked position,

(f) means operable to release said latch plate and allow said locking lever to move to said unlocked position,

(g) said release means including a rotatable button slidably mounted on said locking lever,

(b) means connecting said button member to said latch plate,

(i) a lug member carried by said connecting means,

(j) a flange provided on said bracket,

(k) said lug member movable into engagement with said flange upon rotation of said button in one direction to prevent slidable movement of said button to release said latch plate and said lug member being movable clear of said flange upon rotation of said button in an opposite direction.

References Cited by the Examiner UNITED STATES PATENTS 198,861 1/1878 Steller 292129 480,688 8/1892 Bennett 292207 1,184,638 5/1916 Gillen 292207 1,469,477 10/ 1923 Holden. 1,484,317 2/1924 Barney. 1,650,750 11/ 1927 Vergara. 1,930,298 10/1933 Wiley 292129 1,934,105 11/1933 Totty 292-128 FOREIGN PATENTS 747,263 1/ 1945 Germany.

MARVIN A. CHAMPION, Primary Examiner.

RICHARD E. MOORE, Examiner.

Claims

1. A LATCH DEVICE OF THE CLASS DESCRIBED COMPRISING (A) A SUPPORT MEMBER, (B) A LEVER PIVOTALLY MOUNTED ON SAID SUPPORT MEMBER FOR MOVEMENT BETWEEN OPERATIVE AND INOPERATIVE POSITIONS, (C) A LATCH PLATE SLIDABLY MOUNTED FOR MOVEMENT WITH MOVEMENT OF SAID LEVER, (D) STOP MEANS FOR SAID LATCH PLATE, (E) SPRING MEANS URGING SAID LATCH PLATE INTO ENGAGEMENT WITH SAID STOP MEANS TO MAINTAIN SAID LEVER IN OPERATIVE POSITION, (F) MEANS FOR RELEASING SAID LATCH PLATE TO PROVIDE FOR MOVEMENT OF SAID LATCH PLATE OUT OF ENGAGEMENT WITH SAID STOP MEANS TO ALLOW SAID LEVER TO MOVE TO SAID INOPERATIVE POSITION, (G) MEANS FOR CONNECTING SAID RELEASE MEANS TO SAID LATCH PLATE, (H) A LUG MEMBER OPERABLY ASSOCIATED WITH SAID CONNECTING MEANS, AND (I) A FLANGE ON SAID SUPPORT MEMBER, (J) SAID LUG MEMBER BEING MOVABLE IN ONE DIRECTION BY SAID RELEASE MEANS INTO ENGAGEMENT WITH SAID FLANGE IN SAID OPERATIVE POSITION OF SAID LATCH PLATE TO PREVENT SLIDABLE MOVEMENT OF SAID RELEASE MEANS TO RELEASE SAID LATCH PLATE.