US2494453A

US2494453A - Mechanical page turner

Info

Publication number: US2494453A
Application number: US705322A
Authority: US
Inventors: Reck Frank
Original assignee: AERONAUTICAL RES CORP
Current assignee: AERONAUTICAL RES CORP; AERONAUTICAL RESEARCH Corp
Priority date: 1946-10-24
Filing date: 1946-10-24
Publication date: 1950-01-10
Anticipated expiration: 1967-01-10

Description

Jan. 10, 1950 F. RECK MECHANICAL PAGE TURNER 3 Sheets-Sheet 1 Filed Oct. 24, 1946 INVENTOR M P4444 BY (P E ATTORNEY- Jan. 10, 1950 F. RECK MECHANICAL PAGE TURNER 5 Sheets-Sheet 2 Filed Oct 24, 1946 INVENTOR M H K BY @m i m a/ f m swws ATTORNEYS Jan. 10, 1950 F RECK 2,494,453

MECHANICAL PAGE TURNER Filed Oct. 24, 1946 3 Sheets-Sheet 3 F I\ ATTORNEYS Patented Jan. 10, 1950 MECHANICAL PAGE TURNER Frank Reck, Flushing, N. Y., assignor to Aeronautical Research Corporation, New York, N. Y., a corporation of Delaware Application October 24, 1946, Serial No. 705,322

14 Claims.

1 This invention relates to mechanical page turners, and has for its object the provision of a novel and improved device of this character. The mechanical page turner of the invention is a device for mechanically turning in numerical sequence the pages of a book or the like. It is primarily intended for persons who have lost the use of their arms, and who therefore require the. almost constant presence of an attendant to turn the pages of their reading matter. Turning a page of a book by hand appears to be a simple operation, but when carefully analyzed it is actually somewhat complicated. The first move is picking up the page with the fingers and separating it from the others. Following this, the arm carries the page to the left side and the hand performs asmoothing out operation. If the pages have a tendency to spring back, the hand holds them down while the book is being read. To-reproduce these motions mechanically for persons who are physically disabled, the size, weight and simplicity of the mechanical device are of special importance.

The page turner of the invention is ,of convenient size, light weight, and simple in construction and operation. Its operative parts may be for the most part simple metal stampings. It requires no preliminary preparation of the book, and is easily adjusted for books of various sizes. another, with a minimum of adjustment where the books are of different size. In addition to its use by physically disabled persons, the page turner is admirably adapted to be automatically operated for displaying books and the like in store windows and elsewhere. For the sake of simplicity, book is herein intended to include magazines, pamphlets, catalogues, newspapers and all other reading and display matter in page or equivalent .form.

' In its broad aspect, the page turner of the invention comprises, in conjunction with a suitable support for the book, an element for lifting the page .to be turned and an auxiliary element or finger for turning the lifted page, and means for simultaneously oscillating the two elements across the open face of the book, and means for reversing the direction of movement of the elements when the page-lifting element moves into lifting. engagement with the page to be turned and ior again reversing the direction of movement of the elements when the turning of the page is completed. A follower may be advantageously associated with the auxiliary element for holding down the turned page. In, its more One book may be quickly exchanged for complete aspect, the page turner comprises an oscillatory arm with a reversible motive means connected thereto, and means for alternately reversing the motive means and thereby reversing the direction of movement of the arm. The pagelifting element and the finger are operatively connected to the oscillatory arm so that the finger moves at a substantially faster speed and through a longer path than the element. The invention further contemplates the provision of novel and improved adjustable means for supporting a book, and also a novel and improved easel-like support for the page turner itself or for other articles or devices.

The foregoing and other novel features of the invention will be best understood from the following description taken in conjunction with the accompanying drawings, in which Fig. 1 is a top plan in the direction of the arrow I of Fig. 3 and with the oscillatory arm and associated elements cut away.

Fig. 2 is a front elevation in the direction of the arrow 2 of Fig. 3,

Fig. 3 is a vertical end section on the line 3-3 of Fig. 1,

Fig. 4 is a detail section on the line 44 of Fig. 3,

Fig. 5 is a vertical end section on the line 33 of Fig. 1 showing the easel support in its erect position,

Fig. 6 is a detail section on the line 65 of Fig. 5,

Fig. 7 is a front elevation of the operative elements in their mid-positions,

Fig. 8 is a rear elevation, partly in section, of the operative elements,

Fig. 9 is a left side end elevation, partly in section, of the operative elements,

Figs. 10, 11 and 12 are electric circuit diagrams, and

Fig. 13 is a detail section of the electric circuit contact schematically shown in Fig. 11.

The operative elements of the page turner are assembled on a base Ii] preferably made of molded plastic material, although it may be made of wood, metal or other suitable material. As shown in the drawings, the base is molded of relatively thin plastic material, and is generally rectangular in shape. Its integral depending front, back and end Walls enclose a hollow interior for housing certain of the operative elements. Its top it is flat for supporting a book, and may advantageously have a slight downw-ardinclination toward the reader, The inclination of the top, toward the reader, is conveniently increased, when delongitudinal edge of the member [3, carries a pin l8 slightly off-set inwardly with respect to the longitudinal axis of the member l3 and extending into the adjacent groove it. The lower end of the member 53 is squared, and due to its inward, off-set pivot connection the member can be swung inwardly into contact with the member l2, and because of its squared and cannot bev swung outwardly beyond a position perpendicw; lar to the member 12. With the member 12 horizontally extended behind the base In (Fig. the member was swung to its perpendicular or erect position, and there provides a firm support forthe top I for the base. The inclination of the top may be adjuste d by sliding the member IS in the grooves '56, the nearer the member I3 is to: the front wall- K5, the steeper the inclination. A pin l9, in one or both grooves l6, limits the outward'movement of the member l3 in the grooves: With the member 53 swung down into contact with'the'member l2 the latter can be swung back out-ofthe-way within the hollow interior of-the base (Fig. 3).

A reversible electric motor 23 is mounted on the inside of the back wall 2! of the base and is oper ativ el'y connected through suitable reduction gearingto a swinging or oscillatory arm 23. The lower end ofthe arm 23 is secured to the last gear 22 of the reducing gear train. The arm 23 and gear 22 are rotatably mounted on a bearing pin 24, carried by a bracket 25 appropriately .1.

fastened to thewall 2!. The gear 22 is covered by abircularcapZZ. The other end of the arm 23 carries a pivot pin 25, A lever 21 ispivotally mounted intermediate its ends on the pin 26. The outer end of the lever carries a forwardlyextending' bearing pin 28 f and the inner end; of the lever has twp prongs 29. A pulley 33-is rotatably mounted on thetpin ztadjacent the lever 27. 'Ari L shaped wire finger 3"l is securedto the pulley 38. The pulley has a thick hub 30, in which the shorter section of the finger 3i is radially secured. The other andlonger section of the fl'ng'er'exte'nds forwardly and approximately parallel with the top TI of the base.

"A stationaryreel 32'i's f xed tothe bracket 25, withits axis aligning with the axis of the pin 24. Anendless belt'iiz, fixed to the bottom of, the reel, is wrapped around the reel and doubled around the'f reewheeling pulley 33. The belt is fixed to the reel by inserting its two ends ,33 through an aperture, at the bottom of the rim of the reel andfasten ing the two ends to one face of thereel by a clamp 3 2f (Fig. '7). The. diameter of the 'reel 32 is approximately twice the diameter of thepulley 33. As the arm 23 swingsin either direction, the pulley 39, moving with the arm, swings the belt around the stationary, reel, and since the belt is fastened at onepoint. to the reel, the pulleyis itself rotated on thepin 28 by the swinging belt. The direction of rotation of the pulley is opposite to the direction of its oscillatory movement with the arm 23, and the pulley makes approximately one revolution as the arm 2,3 swings through itsoscillatory path of slightly less than 180-. Y'

The motor 23 is of the reversible type, rotating in one direction when the terminals A and C of its field winding are connected together, and in the other direction when the terminals B and C are connected together. A switch 34, mounted on the arm 23, has a contact 0 movable between two stationary contacts a and b, and electrically conheated by a flexible cable 35 to the terminals C, A and B, respectively. The switch is covered by a casing 34 secured to the arm 23. The switch is of the snap action type and when the contact c is moyed into engagement with one contact a (or b) that engagement is maintained until the contact c is moved into engagement with the other contactb (or a). As hereinafter more fully explained, the prongs 29 of the lever 21 move the contact 0 alternately into engagement with the contacts a and I), thus alternating the direction of rotation of the motor 20 and thereby imparting an oscillatory movement to the arm 23. After each movement of the contact o by the prongs 29, the lever 21- is returned to its center or neutral position by a pair of cooperating plates 36 pivotally mounted on the pivot pin 26 andpositioned between the arm 23- and the lever 27-. Each plate 36 has a rearwardlyprojecting lug 31 on its inner edge and a forwardly projecting lug 38 on its outer edge. A coiled spring 39 secured between rearwardlyprojecting ears 40 on the outer edge ofeach plate biases the plates totheir neutral positions with the lugs 38- engaging theadjacent edges ofthe arm 23. The shank-4i of the pronged end ofthe lever- 2%. is positioned between and in contact with the lugs 31, and the lever is thus held in its neutral position when the plates 33 occupy their neutral positions;

The book to be read restson the top- H of the baseand is-opened to thepage where reading is to begin. The bottom ofthe open bookrests ona transversely adjustable rail 42: The rail isslidably mountedina transverseslot-H, at the centerot the top H, andcan be adjusted forbooks of various sizes. The slidable mounting of the railis shownin Figs. 3 and 4, and comprises a flat metalstr-ip.4-l secured midway of the rail and overlying the slot 43. Pins 45 extendingthrough the slot connect thestrip 44 to aspring strip 43 pressing; against the underside of the top H. A rearwardly extending bracket 41 is slidably mounted on the right side ofthe rail 42, and carries a spring clip 48 at its rear end. The center of the openbook is approximately in alignment with thebearing pin 24 of the pivoted arm 23, and the rail 42' is adjusted so that the top of the book is near the tear (or top) edge of the base top I l The back cover of-the bopk-issecured to thespr-ing clip-48.

Assuming the page turner to be in thepositionindicated'by-the left side dotted lines of, Fig. 2, with the switch contacts a and =c closed toswing the arm-23 clockwise, the motor circuit is closed (as hereinafter explained) and-;the-arm begins its clockwise swing. As the arm moves in the circular path P; the-endless belt 33'rotatesthe pulley 30 counter-clockwise, andthe finger 3,] sweeps from left to rightdnthe actual path P' above and across the face ofthe open bookat-aspeed approximately twice that of the arm 23. Atacky or equivalentpage-lifting element 491s mounted on the forward ends of-thebearing pin 28', and as the arm 23 approaches theend ofits; clockwise swing, the element 49 engages the upper right hand margin of the page to be turnedand arrests m v nt f he l mentan hehear s. pin 28. The position of the elements at this in stant is indicated by the right side dotted lines of Fig. 2. Continued movement of the arm 23 now moves the lever 21 about the pin 28 as a fulcrum, and the pronged end of the lever snaps the movable contact from engagement with contact a into engagement with contact b, thereby reversing the motor 20, and the arm 23 thereupon starts its counter-clockwise swing. The tacky element 46 lifts the page to be turned, and the pulley 30, now rotating clockwise on the pin 28, sweeps the finger 3| toward and behind the lifted page. As the finger moves at approximately twice the speed of the arm 23, it soon contacts the turning page, and takes over the page-turning action, moving the page out of contact with the tacky element and completing the main page turning action. As the arm 23 approaches the end of its counter-clockwise swing, a lug 55 on the lever 21, adjacent the pin 28, engages an upstanding post 51 secured to the back 2| of the base. Continued movement of the arm 23 now moves the lever 21 about the engaging lug and post 5| as a fulcrum, and the pronged end of the lever snaps the movable contact 0 from engagement with contact b into engagement with contact a, thereby again reversing the motor 20, and the arm 23 thereupon starts its clockwise swing, and the cycle of operations is repeated.

While the finger 3|, in its sweep from right to left completes the main page turning action, it ultimately moves beyond and out of contact with the turned page. In order to hold the turned page down, after the finger moves beyond the page, an elongated transparent follower 52 is mounted on the finger and is lightly biased by a spring 53 toward the page when the finger is in its left side position. The follower may advantageously be a light-weight transparent plastic, such as Lucite. As the finger sweeps back and forth, the follower reciprocates across and in contact with the open pages of the book, pressing the turned page into contact with the adjacent pages and holding the page down. The tension of the spring 53 is preferably insufficient to depress the follower when the finger is approximate its right side position, and in this position the followers extend outwardly from the finger as indicated by the dotted lines in Fig. 2.

The main circuit of the motor 20 may be controlled in various ways. The simplest control is a manually operated switch for connecting the motor to the source of electric energy. The electric circuits for this control are diagrammatically indicated in Fig. 10. The field winding terminals A, B and C of the motor 20 are electrically con- I;

nected to the contacts a, b and 0, respectively, of the snap switch 34. The lug 5H and post 5| are assumed to be in operative engagement and the pronged end 29 of the lever 2! has just moved the contact 0 into engagement with the contact a, thus connecting the motor windings to swing the arm 23 clockwise. The motor terminals T are connected to a suitable source of electric energy 54 by a light-touch or micro-switch 55, which may be operated by whatever part of the body the reader prefers. If physically able, the reader will usually operate the switch with the thumb or a finger, but the switch may be hung about the readers neck and operated by the chin, or it may be pinned to the readers garment and operated by the knee, elbow, etc. In using the page turner with this simple switch, the switch 55 must be held closed until page turning is complete. Thus, with the operative parts and electrical connections in the positions assumed in Fig. 10, the

reader, desiring to turn the next page, closes the switch 55, whereupon the motor is energized and the arm 23 starts its clockwise swing. When the tacky element engages the page to be turned, the pronged end of the lever moves the contact 0 into engagement with the contact I) to reverse the motor, and the arm 23 starts its counterclockwise swing. Immediately after the lug engages the post 5| and the reader hears the snap of the contact 0 moving into engagement with the contact a, he releases the switch 55, thereby disconnecting the motor 20 from its source of energy 54. This cycle of operations is repeated each time the reader desires to turn the next page.

Where it is inconvenient for the reader to hold the switch closed during the entire cycle of page turning, a second switch may be provided for maintaining the motor circuit closed during each cycle. Such a control is diagrammatically indicated in Fig. 11. In this figure, the rigid post 5! is replaced by a vertically movable post mounted in bracket 51 and normally biased by a spring 52 to its elevated position. The post 58 carries the movable contact 59 of a microswitch mounted within the base It. In the elevated position of the post, the contact 59 engages the stationary contact 60 of the switch, and the motor 20 is electrically connected to the energy source 55. As shown in Fig. 11, the lug 5!) has just engaged and depressed the post 56 and the lever 2? has moved contact 0 into engagement with contact a to reverse the motor and the post has been depressed to open the contacts and 6E! and stop the motor. When the page is to be turned, the reader has only to momentarily depress the manually operated micro-switch 55, and that momentary energization of the motor 20 is sufficient to raise the lug 50 off the post 55 and permit the contacts 59 and 65 to close. When the cycle of page turning is complete the lug 50 again engages and depresses the post 58 and thereby reverses the motor and opens the

contacts

59 and 60. As often as the switch 55 is momentarily closed, the cycle I of page turning is repeated. Fig. 13 illustrates the manner of attachment of the bracket 51 to the rear wall 2| of the base, with the switch contacts 59 and 65 appropriately mounted within the base. In this figure the post is shown in its elevated position with the

contacts

59 and 60 closed.

The page turner may advantageously be used for display purposes, as for example in a store window. When so used, the manually operated switch 55 of Fig. 11 may be replaced by a rotary switch that momentarilycloses the motor circuit periodically, say at intervals twice or more longer than the cycle of page turning. Fig. 12 diagrammatically illustrates such a rotary switch for automatic operation of the page turner. The contact 6! is rotated at a constant speed by a suitable motive means 62, such as a small constant speed electric motor, and periodically engages a stationary contact 63 to momentarily close the circuit of the motor 20. Each time the contacts BI and 63 are momentarily closed, a complete cycle of page turning takes place, as described in connection with Fig. 11. The intervals between closing of the contacts BI and 63 may be of any desired duration, to allow adequatedisplay of the open pages before the next page is turned.

The tacky element 49 shown in the drawings is a roller of wood or the like having an eyelet pressed through its center and serving asa bear ing. The cylindrical peripheral surface of the roller is covered with a tacky or sticky material. A strip of scotch drafting tape wrapped around the cylindrical surface will pick up a considerable number of pages before requiring replacement. Preferably, the cylindrical surface is coated with a suitably sticky or slightly adhesive material, such for example as a mixture of hectograph compound, glycerine and gelatin. In use, such a mixture picks up lint from the paper, which may be wiped off with a damp cloth, and the roller used for many books. The rollers are inexpensive and a large supply may be kept on hand. The roller is pressed over a spring knob 64 on the forward end of the bearing pin 1 28 (Fig. 9), and rotates freely on the pin, the knob serving to hold the roller on the pin. Various other types of tacky element may be mounted on the forward end of the pin 28 without departing from the spirit of the invention. The function of the tacky element is to lift the page to be turned after the element has engaged the page and reversed the direction of movement of the arm 23, and While I now believe this is best accomplished through the agency of a sticky or slightly adhesive medium, any equivalent agency capable of effecting an initial lifting of the page may be used in lieu of the sticky medium.

I claim:

1. A mechanical page turner, comprising a support for a book, an element for initially lifting the page to be turned of an open book on said support, an auxiliary element for turning the lifted page, means for simultaneously oscillating said elements across the open face of the book with the auxiliary element moving at a substantially faster speed and through a longer path than the element, means erated by the engagement of said page-lifting element with the page to be lifted for reversing the direction of movement of said elements when the page-lifting element moves into liftin engagement with the page to be turned, and means for again reversing the direction of movement of said elements when the turning of the page is completed.

2. A mechanical page turner, comprising a support for a book, an element for initially lifting the page to be turned of an open book .on said support, a finger adapted to engage and turn the page after it has been lifted by said element, a follower connected to said finger and adapted to hold down the turned page, means for simultaneously oscillating said element and finger across the open face of the book, operated by the engagement of said lifting element with the page to be turned means for reversing the direction of movement of said element and finger when the element moves into lifting engagement with the page to be turned, and means for again reversing the direction of movement of the element and finger when the turning of the page is completed.

3. A mechanical page turner, comprising a support for a book, an element for initially lifting the page to be turned of an open book on said support, a finger adapted to engage and turn the page after it .has been lifted by said element, a 01- lower operatively associated with said finger and adapted to :hold down the turn-ed page, means for simultaneously oscillating said element and finger across the open face of the book with the finger moving at a substantially faster speed and through a longer path than the element, and means for reversing the direction of movement of said element and finger "when the element moves into lifting engagement with the page to be turned and for again reversing the direction of movement of the element and finger when the turning of the page is completed.

4. A mechanical page turner, comprising a support for a book, an oscillatory arm, reversible motive means operatively connected to said arm, an element for initially lifting the page to be turned of an open book on said support, an auxiliary element for turning the lifted page, means including said arm for simultaneously oscillating said elements, means actuated by the engagement of said page-lifting element with the page to be lifted for reversing said motive means when the page-lifting element moves into lifting engagement with the page to be turned, and means for again reversing said motive means when the arm completes its next oscillatory movement immediately following the aforementioned reversal of the motive means.

5. A mechanical page turner, comprising a support for a book, an oscillatory arm, motive means operatively connected to said arm, a lever pivotally mounted on said arm, means actuated by said lever for reversing the direction of rotation of said motive means, a free-wheeling pulley carried by said lever, a finger connected to said pulley and adapted to move in a path across support when the pulley is rotated, means whereby the oscillatory movement of said arm rotates said pulley alternately in different directions, a page lifting element carried by said lever and adapted as said arm reaches one end of its oscillatory movement to engage the page to be turned .of an open book on said support with sufficient force to cause said lever to actuate said reversing means, and means for causing said lever to actuate said reversing means as said arm reaches the other end of its oscillatory :movement.

6. A mechanical page turner, comprising asupport for a book, an oscillatory arm, motive means operatively connected to said arm, a lever mounted on said arm, means actuated by said lever for reversing the direction of rotation of said motive means, a page lifting element carried by said lever and adapted as said arm reaches one end of its oscillatory movement to engage the page to be turned of an open book on said support with sufficient force to cause said lever to actuate said reversing means and to initiate lifting of the page upon the subsequent reversal of the movement of said arm, a free-wheeling pulley carried by said lever, means whereby the oscillatory movement of said arm rotates said pulley alternately in different directions, a finger connected to said pulley and adapted to move in a path to turn the page lifted by said element, and means for causing said lever to actuate said reversing means as said arm reaches the other end of its oscillatory movement.

7. A mechanical page turner, comprising a support for a book, an oscillatory arm, reversible mo 'tive means operatively connected to said arm, a lever mounted on said arm andnormally biased to a neutral position and adapted to be moved to either of two operative positions, means whereby said motive means is alternately reversed by the alternate movement of said lever between its .two operative positions, an element carried by said lever and adapted as said arm approaches one .end of its oscillatory movement to engage the page to be turned of an open book :on said support with sufficient force to move said lever to one of its operative positions and to initiate lifting of the page upon the subsequent reversal of the movement of said arm, a free-wheeling pulley carried by said lever, means whereby the oscillatory movement of said arm rotates said pulley alternately in difierent directions, a finger connected to said pulley and adapted to move in a path to turn the page lifted by said element, and means for moving said lever to its other operative position as said arm approaches the other end of its oscillatory movement.

8. A mechanical page turner, comprising a support for a book, an oscillatory arm, a reversible electric motor operatively connected to said arm, a switch carried by said arm and adapted when actuated to reverse said motor, a lever mounted on said arm and normally biased to a neutral position and adapted when moved to either of two operative positions to actuate said switch, a page lifting element carried by said lever and adapted as said arm approaches one end of its oscillatory movement to engage the page to be turned of an open book on said support with sufiicient force to move said lever to one of its operative positions and to initiate lifting of the page upon the subsequent reversal of the movement of said arm, a free-wheeling pulley carried by said lever, means whereby the oscillatory movement of said arm rotates said pulley in a direction opposite to the movement of the arm, a finger connected to said pulley and adapted to move in a path to turn the page lifted by said element, and means for moving said lever to its other operative position as said arm approaches the other end of its oscillatory movement.

9. A mechanical page turner, comprising a support for a book, an oscillatory arm, reversible motive means operatively connected to said arm, means for alternately reversing said motive means and thereby imparting oscillatory movement to said arm, a free-wheeling pulley operatively carried by said arm, a stationary reel positioned with its center in alignment with the pivot of said arm, an endless belt operatively connecting said pulley and reel and fixed at one point to the reel, and a page-turning finger secured to said pulley and adapted to be moved across and approximate the top of the support by the combined action of said arm and pulley.

10. A mechanical page turner according to claim 9, further characterized in that the diameter of the pulley is substantially less than the diameter of the reel whereby the finger moves at a substantially faster speed than the arm.

11. A mechanical page turner, comprising a support for a book, an oscillatory arm, reversible motive means operatively connected to said arm, means for alternately reversing said motive means and thereby imparting oscillatory movement to said arm, a free-wheeling pulley operatively carried by said arm, a stationary reel positioned with its center in alignment with the pivot of said arm, an endless belt operatively connecting said pulley and reel and fixed at one point to the reel, a page-turning finger secured to said pulley, said pulley being of substantially smaller diameter than said reel whereby the combined action of said arm and pulley sweeps the finger across and proximate the top of the support at a substantially faster speed than that of said arm, and an elongated follower operatively associated with said finger and lightly biased toward the top of said support.

12. A mechanical page turner, comprising a support for a book, an oscillatory arm, reversible motive means operatively connected to said arm, a lever mounted on said arm and normally biased to a neutral position and adapted to be moved to either of two operative positions, means operatively associated with said lever for alternately reversing said motive means by alternately moving said lever between its two operative positions, a free-wheeling pulley operatively carried by said arm, a stationary reel positioned with its center in alignment with the pivot of said arm, an endless belt operatively connecting said pulley and reel and fixed at one point to the reel, a pagelifting element carried by said lever and adapted as said arm approaches one end of its oscillatory movement to engage the page to be turned of a book on said support with sufiicient force to move said lever to one of its operative positions and to initiate lifting of the page upon the subsequent reversal of the movement of said arm, a finger secured to said pulley and moving as a consequence of the combined action of said arm and pulley in a path to turn the page lifted by said element, a follower operatively associated with said finger and adapted to hold down the turned page, and means for moving said lever to its other operative position as said arm approaches the other end of its oscillatory movement.

13. A mechanical page turner according to claim 12, further characterized in that the diameter of the pulley is substantially less than the diameter of the reel whereby the pulley moves at a substantially faster speed than the arm.

14. A mechanical page turner according to claim 12 in which the motive means is an electric motor adapted to be reversed by the actuation of a switch mounted on the oscillatory arm, and the lever is operatively associated with the switch to actuate it when moved to either of the levers operative positions.

FRANK RECK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 124,172 Stuart Feb. 27, 1872 1,072,534 Vosper Sept. 9, 1913 2,411,084 Demers Nov. 12, 1946 FOREIGN PATENTS Number Country Date 10,134 Great Britain July 12, 1888 Certificate of Correction Patent No. 2,494,453 January 10, 1950 FRANK BECK It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 66, for actual read arcual; column 7, line 56, after the word "turned strike out means and insert the same in line 54, same column, before operated; column 8, line 27, before support insert said; column 9, line 45, for approximate read proximate;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 16th day of May, A. D. 1950.

THOMAS F. MURPHY,

Assistant C'ommiuioner of Patents.

Certificate of Correction Patent No. 2,494,453 January 10, 1950 FRANK BECK It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 66, for actual read arcual; column 7, line 56, after the word turned strike out means" and insert the same in line 54, same column, before operated; column 8, line 27, before support insert said; column 9, line 45, for approximate read proximate; and that the said Letters Patent should; be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 16th day of May, A. D. 1950.

THOMAS F. MURPHY,

4mm": Commissioner of Patenh.