US2710681A - Page end indicators and paper table extension means for typewriters or like machines - Google Patents

Description

June 14, 1955 H, LAMBERT 2,710,681

' PAGE END INDICATORS AND PAPER TABLE EXTENSION y MEANS FOR TYPEWRITERS 0R LIKE MACHINES Filed Feb. 16, 1953 2 Sheets-$11961'. l

g fwkmmlvlauo LI/lllllllllllllllllll'illll H. l. LAMBERT IJune 14, 1955 2,710,681 PAGE END INDICATORS AND PAPER TABLE EXTENSION MEANS FOR TYPEWRITERS OR LIKE MACHINES Filed Feb. 16. 1953 2 Sheets-Sheet 2 INVENTQR HARRY L Anfnr aPr/Lln- ,@ATTOR United States atent PAGE END INDICATORS AND PAPER TABLE EXTENSION MEANS FOR TYPEWRlTERS OR LIKE MACHINES Harry L. Lambert, West Hartford, Conn., assignor to Royal McBee Corporation, a corporation of New York Application February 16, 1953, Serial No. 336,935

9 Claims. (Cl. 197-189) This invention relates to page end indicators and paper table extension means for typewriters or like machines, and more particularly to such mechanism adapted operatively to be associated with the rotatable sheet feeding platen or cylinder of such an invention.

An object of the invention is to provide page end indicator mechanism of simple construction and which may easily be incorporated in known or conventional typewriters or like machines with a minimum of changing of the basic machine.

Another object of the invention is to provide mechanism of the class referred to which is adapted to be co-operatively related to fractional line spacing mechanism.

A further object of the invention is to provide mechanism of the kind referred to including or in combination with a new and improved rear paper table extension device, especially suitable for use in connection with portable typewriters.

A further object of the invention yis to provide a new and improved paper table extension device for typewriters.

Other objects of the invention will become apparent from a reading of the following detailed description, the appended claims, and the accompanying drawings in which:

Figure l is a front, elevational view of a typewriter carriage equipped with mechanism embodying the invention;

v Figure 2 is a developed view of an indicator scale device positioned alongside a development of a toothed line spacing ratchet wheel;

Figure 3 is a detailed perspective view of a relatively stationary indicator member;

Figure 4 is a fragmentary perspective view illustrating a work sheet with its bottom or trailing edge or end registering with a datum mark; v

Figure 5 is a fragmentary horizontal sectional view of the left end portion of a typewriter platen or sheetfeeding cylinder, and page end indicator mechanism associated therewith, parts being shown in elevation and being drawn on an enlarged scale;

Figure 6 isa fragmentary detailed sectional view on the irregular line 6-6 0f Figure l; and

Figure 7 is Va view from the right end of Figure l, some'parts beingshown in section'and others in elevation.

The invention is illustrated as being embodied in a portable typewriter having many of the standard or known parts and arrangements of parts as those of Royal portable typewriters. The construction illustrated includes a carriage base or rail 1 adapted to travel in letter spacing and return directions on a stationary or frame rail 2. Antifriction balls 3 are interposed between the carriage rail 1 and the frame rail 2. The carriage frame includes end plates 4 and 5, the latter being equipped with a bearing 6 for rotatably mounting a shaft 7 which carries a work sheet feeding platen or cylinder 8. -An operating knob 9 is secured to the right end of the shaft 7 by set screws, one of which is shown at 10 in Figure l.

The shaft 7 extends through a bore l1 in the cylinder 8, the left end of the shaft passing through a sleeve 12 having a flange 13 secured to the cylinder 8 by screws, one of which is shown at 14. In assembling or disassembling the shaft 7 and cylinder 8, the shaft can be slid through the bore 11 and sleeve 12. In order to hold the shaft and cylinder in assembled relation, set screws 15 carried by a boss 16 secured to the right end of the cylinder 3 are tightened. The boss 16 cooperates with the right end plate 5, with the bearing 6, and with the hub of the knob 9 to hold the shaft 7 against axial movement relative to the carriage.

The left end of the shaft 7 is mounted to rotate in a bearing 17 screwed into the left end plate 4, and held in place by a lock nut 18. A knob 19 secured to the left end of the shaft 7 by set screws 20 may be used alternatively with the knob 9 for rotating the cylinder 8 to feed a work sheet S.

A detent device or mechanism is provided for determining deinite line spacing increments of rotation of the cylinder 8. In the form shown, the detent mechanism includes a movable ratchet wheel element 21 secured to the hub of a fractional line spacing clutch part generally designated 22. The part 22 includes a web 23 and a peripheral shroud part 24 formed on its inner surface with a ring of clutch teeth 25. A cooperating clutch element, generally designated 26, is equipped with pins, one of which is shown at 27, extending through a guide bore 28 in the flange 13 of the sleeve 12 and into an enlarged hole 29 in the body of the cylinder 8. A ange 30 secured to the inner end part of the pin 27 serves as a seat for one end of a compression spring 31, the other end of which is seated upon the bottom or root of the enlarged hole 29. The other pins, not shown but similar to the pin 27, are similarly equipped with anges 30 cooperable with springs 31. The arrangement is such that the springs 31, acting on the pin flanges 30, urge the coupling element 26 axially outwardly so as normally to bring the clutch teeth 32 formed in the element 26, into engagement with the clutch teeth 25 on the coupling element 22. Consequently, the ratchet wheel 21 normally is coupled to the cylinder 8 so as to rotate in unison therewith.

For cooperating with the ratchet wheel 21 to determine definite incremental line spacing movements of the ratchet wheel and consequently the cylinder 8, a pawl or roller 33 is mounted on a lever 34 pivoted at 35 on the left hand plate 4. A spring 36 anchored on the end plate 4 and secured to the rear end of the lever 34 urges the lever upwardly so as to hold the roller 33 resiliently in contact with the ratchet wheel 2l, a stop 36a being carried by the end plate 4 and being engageable by the lever 34 for limiting the upward movement of the roller 33.

A combined line spacing and carriage returning lever of a known kind (not shown) may be used for operating the ratchet wheel through the intermediary of an operating arm 37 pivoted on the bearing 17 and carrying a pawl (not shown) engageable with the ratchet wheel 21. Mechanism may also be provided for selectively determining single or multiple line spacing in response to operation of the combined carriage returning and line spacing lever, and such mechanism may include a control arm, a part of which is shown at 38 as being pivoted on the bearing 17. A spacer washer or shim 39 is interposed between the control arm 38 and the operating arm 37.

At times, it is desirable to effect fractional line spacing movement of the cylinder S, that is, a rotary movement of the cylinder, less than a single line spacing movement corresponding to the spacing of the ratchet wheel teeth. For enabling such operation to be performed, mechanism is provided for uncoupling the clutch parts 22 and 26, thus permitting the cylinder 8 to be rotated relatively to the ratchet wheel 21. For this purpose, the left end of the shaft 7 is hollow, being formed with a slot 4G which receives an operating rod or pin 41 equipped at its outer end with a finger operable control member or button 42. A washer 43 secured to the rod 41 inside the hub of the knob 19 is engageable with the hub at the end of the slot for preventing the rod 41 from being withdrawn completely from the slot 4?. The inner end of the rod 41 is adapted to engage and bear against an ear part i4 secured to the clutch member 26.

In order to effect fractional line spacing movement of the cylinder 8, the button 42 is pushed inwardly, causing the rod 41 to press against the ear 44 and shift vthe clutch member 26 axially toward the right as viewed in Figure 5, thereby disengaging the clutch teeth 32 from the clutch teeth 25. The cylinder 8 may then be turned by the knob 19 and shaft 7 while the ratchet wheel 21 is held stationary by the detent roller 33. After the desired fractional line spacing movement of the cylinder 8 has been effected, the button 42 is released, enabling the springs 31 to return the clutch element 26 to its normal position of engagement with the clutch element 22. The clutch teeth 32 and 25 are so tine that, when they become re-engaged, no appreciable relative rotary shifting between the clutch elements 22 and 26 is effected.

The carriage shown in the drawings also includes a paper pan 45 which extends under the cylinder 8, and

feed rollers 46 and 47. A rear paper table 48 is pivoted on the carriage frame as at 49. A paper bail generally designated 59 includes arms 51 and 52 pivoted at 53 on the carriage, and a front rod or bar 54 equipped with paper holding rollers 55.

The construction described so far, considered generally or basically, is known, and does not, itself, constitute the present invention. The invention is embodied in other parts to be described, and combinations of other parts with each other and with the parts already described, Indeed, one of the advantages of constructions embodying the present invention is that they may be incorporated in known typewriter constructions with a minimum of changing of the latter.

Page end indicator mechanism embodying the invention includes an indicator device displaying indicia enabling the operator to be kept advised as to how many line spaces remain available for typing on a work sheet. The device shown is constituted in part by the outer sur face 56 of the clutch element 22, which bears indicia Set and the numerals 8 6 4 2 with accompanying scale lines, and intervening lines for enabling ready interpolation of numerals 7 5 3 l, not actually displayed. The spaces between the lines on the scale correspond to line spacing increments of work sheet feeding, that is to say, correspond to the spaces between adjacent teeth on the ratchet wheel 21 as indicated in Figure 2. The indicator scale lines are adapted to be read in connection with a relatively fixed pointer or scale member 57 carried by the paper bail Sil. The circular indicator device 56 enshrouds the clutch parts 25 and 32.

Normally, when the button 42 is not pressed inwardly, so that the clutch members 22 and 26 are engaged by the springs 31, rotation of the cylinder 8 will be accompanied by conjoint rotation of the indicator device 56. When, however, the fractional line spacing button 42 is pressed inwardly so as to uncouple the releasably engaged clutch elements 22 and 26, the cylinder S may be rotated freely while the indicator device 56 remains stationary.

A paper table extension arm 58 is pivoted at 59 on a mounting plate part 60 secured to the paper table 48 by screws 61, the arm 53 being thus rockable about an axis fixed with respect to the paper table. A companion extension arm 62 crosses the arm 5S and is pivoted at 63 on the arm 58 at a point spaced from the pivotal mounting 59 of the arm 58. A spring friction washer 64 is interposed between the arm 62 and the head of the pivot member 63 as shown in Figure 6. At the lower end of the arm 62 and spaced from the pivot 63 is a pin 65 which extends into an elongated slot 66 in the plate 60 and is movable both pivotally and slidably in the slot. The slot 66 extends generally parallel to the axis of the shaft 7, and the arrangement is such that, when either arm 58 or 62 is moved from a retracted or inoperative lower position as indicated in dotted lines in Figure l to an extended or operative upper position shown in full lines in Figure l, the companion arm will be moved correspondingly. Conversely, when one arm is moved to its retracted position, the other arm will follow. A slot 67 is formed in the rear part of the paper table 48 for cnabling the arms S8 and 62 to extend upwardly from their mounting on the plate 60. The arm 58 is formed with a pressed-out button 68 adapted to snap into a hole 69 in the mounting plate 6i) for releasably retaining the arms 5S and 62 in their raised or extended positions. When the arms are in their extended positions, they conjointly provide, in effect, a continuation or upward extension of the paper table 43 for supporting a work sheet, as shown in Figure 7, so as to prevent the work sheet ends trom sagging down behind the typewriter and coming into contact with the edges of a carrying case (not shown).

In operation, a work sheet S is inserted under and around the cylinder 8 in the usual manner, and, with the clutch members 22 and 26 coupled, i. e. in engagement with each other, the cylinder 8 and consequently the indicator device 56 are turned until the mark Set" on the device 56 registers with the iixed scale marker 57. Then the button 42 is pressed to disengage the coupling members 22 and 26, and the cylinder 8 is rotated until the bottom or trailing edge of the work sheet S registers with a datum line connecting datum marks 70, 70 on the extension arms 58 and 62 and parallel to the axis of the cylinder 8. During the rotation of the cylinder 8 for so positioning the work sheet, the ratchet wheel 21 and hence the indicator device 56 are held against turning by the detent roller 33. The button 42 will then be released, at which time the indicator will register Set, and the bot-v tom edge of the Work sheet will register with the datum marks 70. The cylinder 8 will then be rotated so as to place the work sheet S in the proper position, according to the operators judgment, for the starting of typing at or near the top of the sheet. When the cylinder 8 is rotated to effect line spacing of successive lines, the indicator device 56 will rotate with the cylinder, and, as the bottom of the page approaches the typing line, the numerals 8 6 4 2 O and the accompanying and intervening scale lines will move under the fixed indicator member 57 so as progressively to indicate the amount of space remaining for receiving typing before the bottom of the work sheet reaches the line of typing.

In order that the indicating device may correctly indicate the amount of space remaining for typing, the datum marks 70 are so spaced from the axis of the cylinder 8 in relation to the diameter of the cylinder that, when the operating knob 9 or 19 has been operated with the coupling elements 22 and 26 engaged to set the indicator device 56 in its predetermined starting position, the coupling elements 22 and 26 have then been released or disengaged, and the cylinder 8 has been rotated by the operating knob to bring the bottom edge of the work sheet into registration with the datum marks 70, and the coupling elements 22 and 26 have then been re-engaged, further rotation of the cylinder and consequent incrcmental feeding of the sheet in the line spacing direction will cause the indicator device to indicate the space on the sheet remaining available tor receiving typing as the bottom of the sheet approaches the line of typing. In one example, the necessary relationship of the paris is satisfied when the diameter of the cylinder is approximately one and one-quarter inches, and the distance from the datum marks 70 to the axis of the cylinder is approximately four and one-half inches.

For use with very short work sheets, not long enough to reach from the datum marks 70 to the cylinder 8, the paper pan 45 may be formed with a datum line 71 with which the bottom edges of the short sheet may be caused to register before re-engaging the clutch elements 22 and 26.

The mechanism shown embodies the invention in a preferred form, but it is intended that the disclosure be illustrative rather than definitive, the invention being defined in the claims.

I claim:

1. In a work sheet feeding and positioning mechanism for a typewriter or like machine, the combination of a frame; a sheet feeding cylinder; means mounting said cylinder on said frame for rotation; operating means for rotating said cylinder; detent mechanism including a movable element for determining rotation of said cylinder in predetermined line spacing increments; an indicator device operable conjointly with said detent movable element; releasably engageable coupling means for coupling said detent movable element to said cylinder; a control member for effecting engaging and disengaging of said coupling means; and means providing a datum mark so spaced from the axis of said cylinder in relation to the diameter of said cylinder that when said operating means has been operated with said coupling means engaged to set said indicator device in a predetermined starting position, said coupling means has been released; said cylinder has been rotated by said operating means to bring the bottom edge of the sheet into registration with said datum mark, and said coupling means has been re-engaged; further rotation of said cylinder and consequent incremental feeding of said sheet in the line spacing direction will cause said indicator device, moving conjointly with said cylinder and said detent movable element, to indicate the space on said sheet remaining available for receiving typing as the bottom of said sheet approaches the line of typing.

2. In a work sheet feeding and positioning mechanism for a typewriter or like machine, the combination of a frame; a sheet feeding cylinder; means mounting said cylinder on said frame for rotation; operating means for rotating said cylinder to effect line spacing feeding of a sheet; detent mechanism including, a movable element for determining rotation of said cylinder in predetermined line spacing increments; fractional line spacing mechanism interposed between said operating means and said detent movable element and includinga part operable by said operating means, a part connected to said detent movable element, means for urging one of said parts into coupling engagement with the other of said parts for normally causing said detent movable element to be moved conjointly with said cylinder, and a control member for moving said one of said parts out of engagement with said other of said parts to enable said detent movable element to remain stationary when said cylinder is rotated fractional line spacing amounts; an indicator device operable conjointly with said detent movable element; and means providing a datum mark so spaced from the axis of said cylinder in relation to the diameter of said cylinder that when said operating means has been operated with said parts of said fractional line spacing mechanism engaged to set said indicator device in a predetermined starting position, said parts of said fractional line spacing mechanism have been disengaged, said cylinder has been rotated by said operating means to bring the bottom edge of the sheet into registration with said datum mark, and said parts of said fractional line spacing mechanism have been re-engaged; further rotation of said cylinder and consequent incremental feeding of said sheet in the line spacing direction will cause said indicator device, moving conjointly with said cylinder and said detent movable element, to indicate the space on said sheet remaining available for receiving typing as the bottom of said sheet approaches the line of typing.

3. In a work sheet line spacing and page end indicator mechanism for a typewriter or like machine, the combination of a frame; a sheet feeding cylinder; means mounting said cylinder on said frame for rotation; a hollow operating shaft for rotating said cylinder; a detent ratchet wheel mounted coaxially with respectto said shaft for rotation relative thereto; a spring pressed detent pawl engaging said ratchet wheel for permitting rotation of said ratchet wheel while determining incremental rotary movements thereof corresponding to the spacing between lines typed on the work sheet; a first clutch element rotatable about the axis of said shaft in unison with said ratchet wheel; a second clutch element rotatable about the axis of said shaft in unison with said shaft but being shiftable axially with respect to said shaft; spring means urging said second clutch element axially of said shaft into engagement with said first clutch element fornormally causing said ratchet wheel to be rotated conjointly with said shaft and said cylinder; a manually operable control pin extending through said shaft, engaging 'a part of said second clutch element, and .being movable axially of said shaft for shifting said second clutch element tor disengage it from said first clutch element; a circular indicator device fixed with respect to said ratchet wheel to rotate therewith and enshrouding said clutch elements; and means providing a datum mark so spaced from the axis of said cylinder in relation to the diameter of said cylinder that when said shaft has been rotated with said clutch elements engaged to set said indicator device in a predetermined starting position, said clutch elements have then been disengaged, said shaft has then been turned to rotate said cylinder to bring the bottom edge of said sheet into registration with said datum mark, and said clutch elements have then been re-engaged; further rotation of said shaft and cylinder in the line spacing direction and consequent incremental feeding of said sheet will cause said indicator device, moving conjointly 4. ln a work sheet feeding and positioning mechanism for a typewriter or like machine, the combination of a frame; a sheet feeding cylinder; means mounting said cylinder on said frame for rotation; operating means,

for rotating said cylinder; detent mechanism including a movable element for determining rotation of said cylinl der in predetermined line spacing increments; an indica-4 tor device operable conjointly with said detent movable element; releasahly engageable coupling means for coupling said detent movable element to said cylinder; la control member for effecting engagingandl disengaging of said coupling means; a paper table mounted on said.,

frame at the rear of said cylinder; a pair of paperitable extension arms respectively pivotally mounted at the rear of said paper table and being movable selectively to inoperative lower positions and to operative upper positions in which they conjointly provide an extension of said paper table for supporting a work sheet; and a datum mark on at least one of said arms and'so located thereon that when said arm is in its upper position said datum mark is so spaced from the axis of said cylinder in relation to the diameter of said cylinder that when said operating means has been operated with said coupling means engaged to set said indicator device in a predetermined starting position, said coupling means hasy been released, said cylinder has been rotatedv by said operating means to bring the bottom edgel of the sheet into registration with said datum mark, and said coupling means has been re-engaged; further rotation of said cylinder and consequent incremental feeding of said sheet in the line spacing direction will cause said indicator device, moving conjointly with said cylinder and said detent movable element, to indicate the space on said sheet remaining available for receiving typing as the bottom of said sheet approaches the line of typing.

5. In a Work sheet feeding and positioning mechanism for a typewriter or like machine, the combination of a frame; a sheet feeding cylinder; means mounting said cylinder on said frame for rotation; operating means for rotating said cylinder; detent mechanism including a movable element for determining rotation of said cylinder in predetermined line spacing increments; an indicator device operable conjointly with said detent movable element; releasably erigageable coupling means for coupling said detent movable element to said cyiinder; :i control member for effecting engaging and disengaging of said coupling means: a paper table mounted on said frame at the rear of said cylinder; a pair of paper table exten- Sion arms respectively pivotally mounted at the rear of said paper table and being movable selectively to inoperative lower positions and to operative upper positions in which they coniointly provide an extension of said paper table for supporting a work sheet; means operatively connecting said arms for causing one of said arms to move about its pivot conjointly with movement ot' the other of said arms about its pivot; and a datum mark on at least one of said arms and so located thereon that when said arm is in its upper position said datum mark is so spaced from the axis of said cylinder in relation to the diameter of said cylinder that when said operating means has been operated with said coupling means engaged to set said indicator device in a predetermined starting position, said coupling means has been released, said cylinder has been rotated by said operating means to bring the bottom edge of the sheet into registration with said datum mark, and said coupling means has been re-engaged; further rotation of said cylinder and consequent incremental feeding of said sheet in the line spacing direction will cause said indicator device, moving conjointly Vith said cylinder and said detent movable element, to indicate the space on said sheet remaining available for receiving typing as the bottom of said sheet approaches the line of typing.

6. in a work sheet feeding and positioning mechanism for a typewriter or like machine, the combination of a frame; a sheet feeding cylinder; means mounting said cylinder on said frame for rotation; operating means for rotating said cylinder; detent mechanism including a movable element for determining rotation of said cylinder in predetermined line spacing increments; an indicator device operable conjointly with said detent movable clement; releasably engageable coupling means for coupling said detent movable element to said cylinder; a control member for electing engaging and disengaging of said coupling means; a paper table mounted on said frame at the rear of said cylinder; a first arm pivotally mounted on said frame for movements selectively' to an inoperative lower position and to an operative upper position; a second aim having pivotal connection to said first arm at a point spaced from the pivotal mounting of said tirst arm on said frame; a part on said frame having a slot; a pin carried by said second arm at a point spaced from the pivotal connection between said arms and extending into said slot for both pivotal and sliding movements with respect thereto, whereby movement of one of said arms from inoperative position to operative position, and vice versa automatically etects corresponding movement of the other of said arms, said arms, when in operative positions, coniointly providing an extension of said paper table for supporting a work sheet; and a datum mark on at least one of said arms and so located thereon that when said arms are in their operative upper positions said datum mark is so spaced from the axis of said cylinder in relation to the diameter of said cylinder that when said operating means has been operated with said coupling means engaged to set said indicator device in a predetermined starting position, said coupling means has been released, said cylinder has been rotated by said operating means to bring the bottom edge of the sheet into registration with said datum mark, and said coupling means has been re-engaged; further rotation oi said cylinder and consequent incremental feeding of said sheet in the line spacing direction will cause said indicator device, moving conjointly with said cylinder and said detent movable element, to indicate the space on said sheet remaining available for receiving typing as the bottom of said sheet approaches the line of typing.

7. ln a work sheet feeding and positioning mechanism for a typewriter or like machine, the combination oi a frame; a sheet feeding cylinder; means mounting said cylinder on said trame for rotation; operating means for rotating said cylinder; detent mechanism including a movable element for determining rotation of said cylinder in predetermined line spacing increments; an indicator device operable conjointly with said detent movable element; releasably engageable coupling means for coupling said detent movable element to said cylinder; a control member for effecting engaging and disengaging of said coupling means: a paper table mounted on said frame at the rear of said cylinder; a first arm pivotally mounted on said frame for movements selectively to an inoperative lower position and to an operative upper position; a second arm having pivotal connection to said first arm at a. point spaced from the pivotal mounting of said first arm on said frame; a part on said frame having a slot; a pin carried by said second arm at a point spaced from the pivotal connection between said arms and extending into said slot for both pivotal and sliding movements with respect thereto, whereby movement of one of said arms from inoperative position to operative position, and vice versa, automatically effects corresponding movement of the other of said arms, said arms, when in operative positions. conjointly providing an extension of said paper table for supporting a work sheet; and two datum marks respectively so located on said arms that when said arms are in operative positions a datum line connecting said marks is parallel to the axis of said cylinder, said datum line being so spaced from the axis of said cylinder in relation to the diameter of said cylinder that when said operating means has been operated with said coupling means engaged to set said indicator device in a predetermined starting position, said coupling means has been released, said cylinder has been rotated by said operating means to bring the bottom edge of the sheet into registration with said datum line, and said coupling means has been re-engaged; further rotation of said cylinder and consequent incremental feeding of said sheet in the line spacing direction wiil cause said indicator device, moving conjointly with said cylinder and said detent movable element, to indicate the space on said sheet remaining available for receiving typing as the bottom of said sheet approaches the line of typing.

8. In a typewriter or like machine, the combination of a sheet feeding cylinder; a paper table mounted at the rear of the cylinder; a rst arm pivotally mounted on said paper table for rocking about a pivotal axis fixed with respect to said paper table selectively to an inoperative lower position and to an operative Lipper position; a second arm; a pivotal connection directly between said arms at a point spaced from the pivotal mounting of Said first arm on said paper table and mounting said second arm for movements selectively to an inoperative lower position, and to an operative Lipper position; a part on said paper table having a slot; and a pin carried by said second arm at a point spaced from the pivotal connection between said arms and extending into said slot for both pivotal and sliding movements with respect thereto.

9 10 whereby movement of one of said arms from inoperative References Cited in the file of this patent position to operative position, and vice versa, will auto- UNITED STATES PATENTS matically e'ect correspondng movement of the other of said arms- 864,496 Barney Aug. 13, 1907 9. A construction as set forth in claim 8 in which said 5 955207 Roche Apr' 19 1910 arms cross each other at the pivotal connection between FOREIGN PATENTS said arms, and in which said slot is substantially hori- 408,952 Germany Jan. 29, 1916 zontal.

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