US3490370A

US3490370A - Rubber stamp printing set

Info

Publication number: US3490370A
Application number: US693532A
Authority: US
Inventors: Fritz Wilhelm Pfannenschwarz
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-12-31
Filing date: 1967-12-26
Publication date: 1970-01-20
Anticipated expiration: 1987-01-20

Description

1970 F. w. PFANNENSCHWARZ 3,490,370

RUBBER STAMP PRINTING SET Filed Dec. 26. 1967 3 Sheets-Sheet 1 .9 AAA/Ina BBBBbbb Ccccu Fig.3

Jan. 20, 1970 F. w. PFANNENSCHWARZ 3,490,370

RUBBER STAMP PRINTING SET Filed Dec. 26, 1967 3 Sheets-Sheet 2 Jan. 20, 1970 F. w. PFANNENSCHWARZ 3,490,370

RUBBER STAMP PRINTING SET Filed Dec. 26, 1967 3 Sheets-Sheet 5 im 1b; 'l fxi Fig. 13 u u U United States Patent RUBBER STAMP PRINTING SET Fritz Wilhelm Pfannenschwarz, Hauptstrasse 8, Nordheim, 7107 Wurttemberg, Germany Filed Dec. 26, 1967, Ser. No. 693,532 Claims priority, application Germany, Dec. 31, 1966, P 28,508 Int. Cl. B44b 5/00; B41k N00 US. Cl. 101381 20 Claims:

ABSTRACT OF THE DISCLOSURE A rubber stamp printing set comprises a plurality of rubber type blocks, means for holding a plurality of the type blocks for printing and a case for the type blocks and holding means. The type blocks are cubical with a raised printing character on the bottom face, a preferably recessed identifying character on the upper face and slots in opposite side faces. The holding'means comprises a slide bar having spaced tongues which engage in the slots in the type blocks and a holder of channel cross section with grooves on inner faces of opposite side flanges to receive the tongues of the slide bar and thereby retain the type blocks. At least the top of the holder is transparent so that the identifying characters of the type blocks can be seen. Means is provided for securing a plurality of holders in assembled side-by-side relations. The case has a slotted plate engaging the slots of the type blocks to to hold them in place and means cooperating with the securing means on the holders to position them in the case.

The invention relates to a rubber stamp printing set comprising a case containing interchangeable elastic type which have printing characters on their bottom faces and legible identification characters on their upper faces which can be seen when the type are set in a holder for printing.

The stamp set in accordance with the invention is particularly suitable for instruction, but can also be used in any oflice where there is a need for rubber stamps with a text which is frequently changed so that a stamp with fixed type is not Worthwhile. For good printing results it is desirable for the type to be securely held in their holder and that moreover, for the stamp characters to be visible at all times including during stamping and in particular when selecting different previously prepared stamps. This is of particular importance in educational toys. In accordance with the invention, the continuous and complete visibility of the characters does not interfere with satisfactory application of pressure to the type during printing. In spite of these advantages, the holder and the further elements are of simple construction so that the stamp set can be produced and sold at a low price. There is also provided a simple and orderly storing of the type. Moreover, the type can easily be removed from the storage positions and inserted in the holder- The holder which encloses three sides of the type has at least the top portion transparent so that the type can be seen through it. Through the transparent construction of the holder, the legends which are usually placed on the tops of the type blocks can be seen even when the type has been inserted in the holder. Moreover, the holder is fashioned as a grip so that it is not necessary to have the usual round or long grip provided over the stamp. Because the elastic type are enclosed on three sides by the holder and on two further sides by neighboring type blocks, they can not be readily deformed. They are thereby retained in proper position during application of pressure on the surface to be printed so that a very clean impression is obtained. In spite of this, the stamp identification characters are always visible.

Although the transparent portions for identification of the characters of the type can be formed as small slits not impairing the support, it is particularly advantageous for the transparent portions to be formed of transparent plastic or the like so that substantially the entire upper face of the type is supported. The identifying characters can be made as large as desired. The transparent portion is particularly easily produced when the entire holder is formed of transparent plastic material.

In order to secure the type satisfactorily in the holder as well as to store them in selected arrangement in the stamp case, a further feature of the invention is that the type are provided on opposite sides with slits that receive a double tongue slide-bar which is insertable in the holder and can be secured in place. The slide bar serves as a setting frame in which individual type are inserted to compose the type line. Moreover, by means of the slits, the type can be inserted in a correspondingly slotted plate in the cage for storage in an orderly arrangement.

An easily produced holder in which the type can be easily inserted and which provides a good grip consists advantageously of an elongated housingtof channel cross section, the underside and one end of which are open. On the opposite inner side walls of the housing there are longitudinally extending grooves, the width and depth of which correspond to the portions of the tongues of the slide bar projecting beyond the type. The slide bar carrying the type is inserted in the grooves through the open end of the housing. In order to cover the open end of the housing and to facilitate insertion and removal of the type, the slide bar is preferably provided with an upwardly projecting tongue which preferably extends above the upper edge of the housing. The slide bar can be easily and economically produced as a steel or sheet metal stamping. Because of their low price, which is much less than that of the holders, a large number of slides can be provided with a set. A stamp having the desired text can be composed by assembling the required type on a slide bar. The type can be left on the slide bar when it is desired to use the holder for another stamp. It is hence unnecessary to remove and sort all of the type each time a new stamp is needed since the stamp text can be left on the slide bar. In order for the type to remain on the slide bar when inserted in and removed from a holder, the slots in the type are preferably formed so as to grip the tongues of the slide bar firmly while the type have a looser engagernent with the inner walls of the holder. The securing of the type on the holder can also be attained or assisted by forming the tongues so that their free ends converge. In order to secure the slide bar and assembled type in the holder, insofar as the elasticity and gripping of the type does not suffice, the ends of the tongues extend into openings in the end wall at the closed end of the holder and are preferably provided with notches and teeth engaging corresponding portions of the holder.

In order that the transparency of the upper portion of the holder through which the identifying characters holder. It is then possible to assemble a plurality of holders next to one another and it is not necessary to have a special holder for multiple-line printing. An advantageous and simple manner of providing means for connecting adjacent holders is to provide on the side walls of the holders pins and holes which are so arranged as to engage corresponding holes and pins on the side wall of an adjacent holder. In the event one pin breaks, the remaining pins provide adequate means for securing the holders together. The pins and holes further assure that an individual holder can be securely gripped during use.

Alternatively, a dove tail connection between adjacent holders can be obtained by providing a dove tail groove on one of the longitudinal side walls of the holder and a corresponding dove tail tongue on the other. The tongue and groove of adjacent holders interengage with one another to secure the holders together. While this provides a still better connection than the embodiment with pins and holes, it has the disadvantage that upon breaking of the dove tail connection, the holders can no longer be connected. The production of the connecting means is particularly simple when the holder is molded of transparent plastic material. The connecting means is produced during molding merely by providing an appropriate die. Hence no special tools are required. The means for joining two or more holders can also advantageously be used for securing the holders in the stamp case merely by providing corresponding interengaging means in the case to cooperate with the connecting means on the holders.

In order to store the type in the stamp case, there is provided a plate having a thickness corresponding to the slots provided in opposite sides of the type and having storage slots in which the type can he slipped. Underlying the slotted plate, there is preferably a printed sheet having printed characters which appear through the slots to indicate the positions in which corresponding type is to be stored. It is hence possible to see at a glance whether all type having like letters are in the case or whether some have been lost. So that it is not necessary to extend the storage slots to the edge of the plate, which would impair the stability of the plate and require additional connections, the storage slots in the plate are provided with wider portions so that individual type can be inserted through these enlargements. Advantageously several wider portions are provided in each of the storage slots so that the distance the type have to be pushed along the slot is not great. However, with this arrangement there is the danger that, particularly when used by children, the type might not be arranged in the correct place. For stamp sets to be used by children, a better arrangement is to provide a wider portion at one end only of each slot. *It is then not necessary to provide an underlying printed sheet bearing indicia to identify the slots but sufiices merely to provide the corresponding characters on the slotted plate adjacent the corresponding enlargements. Still other arrangements may be used to identify the storage slots.

The stamp case may be in the form of a portfolio or in the form of a molded plastic case having a hinged cover. A slotted plate for storage of the type blocks by engagement with slots in the sides of the type can readily be mounted in a stamp casing molded of plastic material by providing in the side walls of the casing grooves to receive the slotted plate. The plate is spaced upwardly from the bottom of the casing to provide space for receiving the lower portions of the type blocks. In order to save room, the slotted plate may be provided only in that portion of the casing where it is desired to store type.

There is also preferably provided a pair of tweezers for taking the type out of the casing and setting it in a'slide bar. The tweezers are preferably provided on their holding end with offsets, the spacing of which corresponds to the spacing between the inner portions of the slots in the type. There is thus provided on the ends of the opposite legs of the tweezers, projections which can be in: sertedbetween the edges of the storage slots of the type casing'and engage opposite sides of individual type. The offset assist in guiding the type so that the elastic type do not jam in the slots of the slotted plate.

Although the identifying characters on the upper faces of the type blocks can be printed'or raised, it is pa'rticularly advantageous to have them recessed in the type block so that there is a limited surface lost for the application of pressure by the holder. A simple printed character is easily worn off and a raised character would interfere with use of the entire surface of the type for applying pressure.

The invention will 'be more fully understood from the following description of preferred embodiments shown by way of example in the drawings in which:

FIG. 1 is a perspective view of an open stamp case in accordance with the invention;

FIG. 2 is a perspective view of tweezers to be used in handling the type;

FIGS. 3 and 4 are respectively an enlarged perspective view and a side view of a type block; 7 p

FIG. 5 is a perspective view of a slide bar,

FIG. 6 is a perspective view of a holder,

FIG. 7 is an enlarged cross'section of a holder with a slide bar and type therein,

FIG. 8 is a longitudinal section through a'holder with a dove tail connection,

FIG. 9 is a cross section taken approximately on the line 99 in FIG. 8,

FIG. 10 is a plan view of the holder shown in FIGS. 8 and 9,

FIG. 11 a longitudinal section of a holder with pin and hole connecting means,

FIG. 12 is a cross section taken on the line 12-12 in FIG. 11,

FIG. 13 .is a plan of the holder of FIG; 11,

FIG. 14- a longitudinal section of a holder without side connecting means,

FIG. 15 is a cross section taken on the line 15-15 in FIG. 14,

FIG. 16 is a plan of the holder of FIG. 14, and

FIG. 17 is a partial section of a molded plastic stamp case with a slotted type-storage plate.

The stamp case 1 shown in FIG. 1 is of portfolio type and can suitably be made of plastic film or sheet material by solvent or thermal welding. It has a left cover 2 the outer corners of which are provided with spacers 3 which prevent direct contact with the right cover 4. The inner surface 5 of the left cover 2 serves to receive training texts, instruction for use, and the like. The two covers 2 and 4 are connected with one another by a hinged or flexible back portion 3a.

In the upper portion of a plate 4a, on the inside of the right cover 4, there are provided rows of slots 6 which have spaced wider portions 7. The enlargements 7 of the slots 6 are wide enough to receive a type block 8 so that the lower portion of the type block can be inserted through the enlargement and slits 18 provided in the sides of the type block can be slid over the edges of the slots 6 to retain the type in the slots. The plate 4a-is provided with any desired number of slots andis suitably spaced from the cover 4 or arranged loose from the cover, for example by being attached only at one edge adjacent the back 3a. If desired a plurality of plates 4a can be superimposed on one another in the case. As see in FIG. 1, a sheet underlying the plate 4a is printed with letters or other suitable characters 9 which are visible through the slots 6 and enlargements '7so as to indicate which-type are to be inserted in particular slots.

Below the slots 6, and as a possible variation, there are shown two adjacent slots 6a each of which is provided with an enlargement 7a at its left end. Adjacent the en largements 7a there are letters or characters 9a to indicate which type are to be inserted in the respective slots.

In the lower portion of the right cover 4 of the case 1 there is'shown a type holder 10 which is provided with pins and holes adapted to interfit-with corresponding holes and pins of like holders to position a plurality of holders in assembled relationship. The holder is shown in more detail in FIGS. 11 to 13. The holder 10 is secured in place in the case 1 by suitable means which are not shown in the drawing but may consist of mating holes and pins provided on the cover 4 or on the plate 4a in which the

slots

6, 6a are provided.

There is also shown in FIG. 1 a type holder 11 provided with dove tailed connectiing means as illustrated in FIGS. 7 to 10. The holder 11 is secured in place inside the cover by dove tail clamps 13 provided on the inside of the cover or on the plate 411.

Any desired number of type holders can be provided in the cover. For the sake of clarity, the type holders are shown disproportionately large in relation to the cover in FIG. 1. Moreover, slots and type holders can, if desired, be provided on the left cover 2 as well as on the right cover 4. Alternatively, slots can be provided on one cover and type holders on the other.

FIGS. 3 and 4 show a generally cube-form type block 8 formed of elastic rubber or plastic material. On its upper face 14, the type block is provided with a deep impression 15 of the letter or other character carried by the type block, here shown as the letter E. The underside 16a of the block is provided with raised type 16 of the character that is to be printed. Opposite side faces 17 are provided over the entire length of the type block 8 with slits 18.

In FIG. 5, there is shown a slide bar 19 formed, for example, of sheet metal or plastic and provided with spaced longitudinally extending tongues 20 forming a slot 21, the width of which corresponds to the distance between the inner portions of the slits 18 of the type blocks so that the type blocks 8 can be slipped onto the slide bar 19 with the tongues 20 of the slide bar received in the slits 18 of the type blocks. The tongues 20 of the slide bar 19 are sufficiently wide to project beyond the sides of the type blocks and be received in grooves 33 on the inside of the holder 12 as illustrated in FIG. 7. The right ends of the tongues 20 are rounded to facilitate introducing the type blocks into the slot 21 and inserting the slide bar 19 into the grooves 33 in the holder 12. The left end 22 of the slide bar 19 is closed and is provided with an upwardly bent tongue 23. As seen in FIG. 7, the tongue 23 projects up above the upper face 24 of the holder 13 so that it can easily be grasped even when the slide bar is assembled with the holder and type blocks.

In FIG. 6, there is shown a holder 12 formed wholly from clear or at least transparent plastic material and provided on its longitudinal side walls with concave, rubber gripping surfaces 25. The holder is formed as an elongated channel of generally rectangular cross section and the underside 26 is provided with an opening 27. The left end 28 is also open while the right end is closed by an end wall 44 having an upwardly projecting web 29 as seen in FIGS. 6 and 14 to 16. The side walls of the holder have upwardly projecting web portions 31 which extend up above the clear, or at least transparent, upper surface 30 so as to protect it from scratching that would interfere with its transparency.

The opposite inner faces 32 of the holder 12 are provided with longitudinally extending grooves 33 to receive the tongues 20 of the slide bar 19 in the manner which is illustrated in FIG. 7, which shows type blocks assembled in a holder 11 of the kind illustrated in FIGS. 8 to 10. The front ends of the grooves 33 'are preferably widened to form funnel-shaped entrance portions to facilitate insertion of the slide bar 19.

In FIG. 2, there are shown tweezers 34 having a gripping end 35 provided with offsets 36 which between them form reduced portions 37 the width of which corresponds to the width of the slot 21 of the slide bar 19 and the

slots

6, 6a of the case 1.

When it is desired to assemble a stamp, the operator takes a slide bar 19 in one hand and the tweezers 34 in the other, guides the gripping end 35 of the tweezers on opposite sides of the first letter desired on the right cover 4 of the case 1 and inserts the holding end of the tweezers until the offsets 36 engage the plate 4a, then presses the opposite portions of the tweezers together and slides the selected letter to the adjacent enlargement 7 of the slot 6 and lifts it out. He then slides the letter onto the slide bar 19 so that the legible representation 15 of the type block 8 faces uuwardly. When the slide bar 19 has been provided with the desired letters and with non-printing end and spacer blocks, the operator slides it in one of the

holders

10, 11 or 12, removed from the cover 4, so that the type face 16 projects outwardly of the holder. The legible representations of the respective characters on the upper faces of the type blocks are positioned under the upper face 30 of the

holder

10', 11 or 12.. As this is formed of clear or transparent plastic and is smooth and blank, the legible characters on the tops of the stamp blocks are clearly seen through it. The operator holds the stamp by the longitudinal side faces and can use it like any other, but the stamp text can be seen through the transparent surface 30 so that any errors in the selection or positioning of the type blocks can be detected and it can be ascertained whether the correct word is being used.

As the type blocks fit closely between the inner walls 32 and lie closely under the upper wall 38, they are supported by these walls when printing pressure is applied to the type. As the type blocks 8 are quite elastic, they conform to the walls of the holder. The type blocks are thus supported on three faces by the holder and on two faces by adjacent type or spacer blocks, so that distortion of the type by the printing pressure is avoided.

In FIGS. 8 to 16 like parts are designated by the same reference numbers. In FIGS. 8 to 10, there is shown a type holder 11 provided on one longitudinal side wall 39 with a dove tail groove 40 extending the full length of the holder and on the other side wall 41 with a dove tail tongue 42 which likewise extends the full length of the holder. The tongue 41 is adapted to engage in a groove 40 of a further holder 11 so that any desired number of holders can be assembled side-by-side.

In this and in the following examples illustrated, openings 43 are shown provided in the end wall 44 of the holder to receive the ends of the tongues 20 of the slider 19. The tongues 20 can, if desired, be provided with small notches or ribs on their side edges which engage corresponding ribs or notches of the holder to secure the slide in assembled position.

FIGS. 11 to 13 illustrate a holder 10 which on its opposite side walls is provided with pins 45 and holes 46. When two such holders are assembled side-by-side, the pins of one holder engage holes in the other holder so as to position the holders in assembled relation. 'In the example shown in the drawings, a pin and a hole are arranged in pairs.

FIGS. 14 to 16 show a holder 12 which has already been described in connection with FIG. 6.

The tongues 20 of the slide bar 19 may converge slightly toward the open end of the slide bar, being made sufiiciently resilient to spring apart to receive the type blocks when they are inserted. The closeness of fit of the several parts may be selected as desired.

In FIG. 17, there is shown a stamp case comprising a one piece plastic housing having side walls 47, a bottom 48 and a hinge joint 49 for attachment of a hinged cover 50. The side wall 47 is provided with a groove 51 spaced from the bottom 48. A plate 52 set into the groove 51 is provided with

slots

6, 6a to receive type blocks 8, the under portions of which are accommodated in a space 53 below plate 52. The plate 52 extends only over that portion of the housing which is to be used for storage of the type blocks 8.

An important advantage of the invention is that the elastic type are very well supported for application to the Work with satisfactory pressure although the characters are at all times visible. The type are very neat and easilv set in proper position. In the setting of the type, the sliding rubber faces are held relatively lightly so that there is no great frictional resistance. Through the proper use of the tweezers, this can be still further reduced. The stamp text can be assembled before hand on a cheap slide bar and put into a holder only for the printing operation. Even after the type has been introduced into a holder, the characters are readily recognizable and are not obscured by portions of the holder. The setting slide is simple and inexpensive to produce and serves also to anchor the type in the holder. The slide is not very large and hence takes only a small amount of room when it is desired to provide a large number of slides in a portfolio or case. The type are elastically held without the need of additional springs. The holder consists of only one piece and is very easy to produce by various plastic molding techniques in particular injection molding.

It will be understood that the various features of the embodiments herein shown and described by way of example, are mutually interchangeable and that other modifications may be made.

What I claim is:

1. A rubber type printing set comprising a plurality of elastic type blocks of rectangular prism shape each having a type character on its lower face, a corresponding identification character on its upper face and longitudinal slits on opposite side faces; holding means comprising a slide bar having spaced elongate tongues receivable in said slits to retain an assembly of type blocks on said slide bar, and a holder of channel section open at the bottom and at one end to receive an assembly of type blocks on said slide bar, said holder having a transparent top wall through which said identification characters of said type blocks are visible and opposite side walls, inner faces of opposite side walls of said holder having longitudinal grooves to receive said slide bar, and a case comprising an enclosure and a plate in said enclosure having slots to receive said type blocks with edges of said slots engaging in said slits, each of said slots having at least one enlarged portion of suflicient width for introduction of said type blocks through said enlarged portion, and means for securing in said case at least one said holder.

2. A printing set according to claim 1, in which said case comprises a surface spaced below said slotted plate and identification symbols on said surface and visible through said slots, said symbols corresponding to identification characters of said blocks and indicating correct positioning of said blocks in said slots.

3. A printing set according to claim 1, in which said set includes at least two said holders with interlocking connecting means on side walls of said holder for securing said holders together in side-by-side relationship and in which said means for securing said holders in said case include means in said case engaging and cooperating with said connecting means on said holders.

4. A printing set according to claim 1, in which said case is a portfolio with two covers and a back portion hingedly connecting said covers.

5. A printing set according to claim 1, in which said case is a molded plastic housing with a bottom and grooved side Walls and said slotted plate is received in grooves in said side walls and spaced from said bottom.

6. A printing set according to claim 1, further comprising type-block-handling tweezers having a gripping end with offsets defining reduced end portions of a width to be received in said slots of said plate and between said tongues of said slide bar.

7. A printing set according to claim 1, in which means is provided on the side walls of said holder for connecting a plurality of like holders together in side-by-side relationship for multiline printing.

8. A printing set according to claim 7, in which said connecting means comprising interengaging pins and holes on the side walls of said holders.

9. A printing set according to claim 7, in which said connecting means comprises a longitudinally extending dove-tail tongue on one side wall of each holder and a corresponding longitudinally extending dove-tail groove on the opposite side wall.

10. A printing set according to claim 1, in which said identification character of said type block is recessed, the entire remaining upper face of said block being engageable with the top wall of said holder for support during application of printing pressure.

11. A printing set according to claim 1, in which said plate of said case has adjacent at least one said enlarged portion of at least one said slot an identification symbol indicating which type blocks are to be inserted in the respective said slot.

12. A rubber type printing set comprising a plurality of elastic type blocks of rectangular prism shape, each having a type character on its lower face, a corresponding identification character on its upper face and longitudinal slits in opposite side faces; holding means comprising a slide bar having spaced parallel elongate tongues joined at one end by a closed portion and receivable in said slits to retain an assembly of type blocks on said slide bar, and an elongate holder of channel section open at its bottom and at one end to receive an assembly of type blocks on said slide bar, said holder having a transparent top wall through which said identification characters of said type blocks are visible and opposite side walls, inner faces of opposite side walls of said holder having longitudinal grooves positioned to receive said slide bar, said top wall and side walls closely embracing said type blocks on three sides to support said blocks during application of printing pressure to said blocks by said holder.

13. A printing set according to claim 12, in which said holder comprises an integral molding of transparent plastic.

14. A printing set according to claim 12, in which said holder has upstanding side webs projecting above said transparent top Wall to protect it from scratching.

15. A printing set according to claim 12, in which said slide bar is provided on said closed end portion joining said tongues with an upstanding tongue which projects above the top wall of said holder when said type blocks and slide bar are assembled in said holder.

16. A printing set according to claim 12, in which said slide bar and holder are provided with interlocking means for releasably securing said slide bar in said holder.

17. A printing set according to claim 16, in which said holder is closed at one end and in which said closed end of the holder is provided with openings to receive end portions of said tongues of said slide bar when said slide bar is in said holder, said locking means comprising interengaging ribs and recesses on said tongues and edge portions of said tongues of said slide bar when said slide bar is in said holder, said locking means comprising interengaging ribs and recesses on said tongues and edge portions of said openings.

18. A printing set according to claim 12, in which said type blocks engage said slide bar with greater frictional force than said holder, whereby said type blocks are retained assembled on said slide bar during insertion in and removal from said holder.

1'9. A printing set according to claim 12, in which said tongues of said slide bar are resilient and in relaxed condition converge toward their free ends.

20. A rubber type printing set comprising a plurality of elastic type blocks each having a type character on its lower face and longitudinal slits in opposite side faces, holding means comprising a holder of channel cross section to receive said type blocks and a bar having spaced elongate tongues with a slot between said tongues, said holder being open at the bottom and having longitudinal grooves in inner faces of opposite side walls, said type blocks being receivable in said holder and in said slot of said bar with said tongues received in said slits of the type block and in said longitudinal grooves of said holder, storage means for said type blocks comprising a plate having slots to receive said type blocks with edges of said slots engaging in said slits, each of said slots in said plate having an opening for insertion of said type blocks into said slot, and type block handling tweezers having a gripping end with offsets defining reduced end portions of a width to be received in said slots of said plate and between said tongues of said bar.

1,078,601 11/1913 Matthews 101-381 RuflFalo 101-381 Lotz 101-381 Wheeler 101-381 McAneny 101-405 X Towers 101-28 X Grifiin 101-368 Devon et a1. 101-381 Munson 101-398 X Rothman 101-381 WILLIAM B. PENN, Primary Examiner