Improvements in Dovetailing Machines.
Year: 1899

page_text: Date of Application, 4th July, 1899-Accepted, 12th Aug., 1899
Improvements in Dovetailing Machines.
I, JOHN EMILL ERICKSON, Mechanic, residing at No. 118, Lafund Street, in
the City of St. Paul, County of Ramsey, and State of Minnesota, United States
of America, do hereby declare the nature of my invention for dovetailing machines
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
My invention relates to the type of dovetailing machines, in which the dove-
tails, or mortises with receding sides, are formed in the ends of boards carried
on a reciprocating table which co-operates with two sets of cutters of successively
increasing diameters; and in which the tenons are formed in boards on a
stationary table by the diagonal reciprocations of two sets of cutters of equal
diameters. In the machine of the patent referred to the cutting of mortises was
done only during the upward movement of the reciprocating table; and tenons
were cut only during the downward thrusts of the cutter carriers; the respective
driving cranks making complete revolutions before stopping. It is one of the
objects of the present improvement to so organize the operating mechanisms that
they will stop automatically at each half throw of the cranks, and thus enable
cutting to be done at each reciprocation of the table in the one instance and of the
saws in the other. A further object of the improvements is to provide devices
operating automatically both to clamp the boards in place on the tables during
the cutting operation and release them upon completion of the cutting. Other
improvements relate to convenient means for adjustment of parts for holding
boards of different thicknesses; means for adjusting the board guides relative
to the saws; and other details of structure; all of which improvements tend
to greatly increase the capacity of the machine for turning out finished work.
As the purpose of the machine is to prepare boards for making boxes, and
especially to enable low grade lumber to be used for packing-boxes and other
cheap boxes, the importance of such improvements as facilitate the work, increase
the out-put and better adapt the machine to successfully operate upon the
cheaper grades of material, is apparent.
The improvements are illustrated in the accompanying drawings, in which
Fig. 1 is a side elevation of the improved dovetailing machine; Fig. 2 an
elevation of that end of the machine at which dovetail mortises are cut; Fig. 3
an elevation of the table shown in Fig. 2, and connections, showing the positions
of parts when boards may be inserted or removed; Fig. 4 shows an elevation of
the opposite end of the machine, at which tenons are formed, the table being
swung to one side to show more clearly the interior mechanisms; Fig. 5 is a
plan view showing in outline the general arrangement of the mechanisms for
reciprocating the table and saws, respectively; Fig. 6. is a detached view of
devices employed at the tenon-forming end of the machine for controlling the
board-clamping devices; Fig. 7 is a detached view of devices employed for

page_text: adjusting a movable portion of the table and the clamp as required for boards
of different thicknesses; Figs. 8, 9 and 10 are details of the devices comprising
the adjustable portion of the table; and Fig. 11 is a detached view of a portion
of the friction and brake devices used in starting and stopping the saw and
table reciprocating mechanisms.
In the drawings 1 designates the machine frame, 2 the main driving shaft and
3 the pulley thereon connected with a source of power. For driving the arbors
of the tenon-cutters, which are at the same end of the machine as the shaft 2,
pulleys on the latter shaft are connected by belts 4 and 5 respectively with
pulleys 6 and 7 on shafts 8 and 9 at the opposite end of the machine, and from
pulleys 10 and 11 on the latter shafts respectively, belts 12 and 13 are run
to pulleys 14 and 15 on shafts 16 and 17 near the top of the frame; and from
pulleys 18 and 19 on the latter shafts belts 20 and 21 respectively are run to the
pulleys 22 and 23 on the upper and lower saw arbors 24 and 25.
The saw
arbors 26 and 27 at the other end of the machine are rotated by belts 28 and 29
on pulleys 30 and 31 connected with over-head shafting, (not shown).
The saws 32 on the arbors 26 and 27 are circular and of successively increasing
diameters, the series forming a contour like the frustum of a cone. "The several
saws of the series may be separated by washers and connected in any well known
manner. These saws have their edges beveled to a common plane and are placed
in such positions relative to each other and to the bed that they may cut dovetail
mortises by two successive cuts, as referred to in my former patent.
The cutters 33 on the arbors 24 and 25 are of equal diameters and are pre-
ferable circular saws, separated by washers or otherwise suitably spaced and
secured. The upper arbor, 24, is mounted on a frame or sash 34 arranged to
slide in angularly-arranged guides 35 provided on the main frame; and the
arbor 25 is similarly mounted on a sash 36 arranged to slide in guides 37 inclined
in direction opposite that of the guides 35. A bar 38 is connected by pivots 39
to central portions of these sashes, so that their reciprocatory movements will
be made in unison. A pitman 40 is pivoted at one end to the sash 30 and at
its opposite end to a crank-arm 41 on a shaft 42 that is mounted in bearings on
the base portion of the machine frame and extending centrally inward.
A .com-
plete rotation of this shaft will obviously cause one downward and one upward
reciprocation of the connected frames and the saws they carry.
On the inner end of the shaft 42 is a beveled gear 43, and in mesh with it is
a beveled pinion 44 on a shaft 45 that extends laterally to the outside of the
frame and there carries a gear-wheel 46. In mesh with the latter gear is a
pinion 47 on a shaft 48 which carries also a friction-wheel 49, the shaft having
suitable bearings on the base member of the machine frame. Thus the rotation
of the friction-wheel 49 causes the rotation of the shafting and gearing just
described and thereby operates the crank 41 to reciprocate the saw frames 34
and 30.
For engaging the friction-wheel 49 at intervals of time to revolve it, a friction-
wheel 50 is provided on a shaft 51 that carries a pulley 52 which is belted to a
pulley on the main driving shaft 2, whereby the shaft 51 and the friction-wheel it
carries are kept in constant rotation. The shaft 51 is mounted on the angular
arm of a lever-frame 53 that is pivoted at 54 to a portion of the machine frame,
and extends downward near the face of the pulley 49 to a point at the side of the
base of the machine frame. On the side of the lever 53, adjacent the friction-
wheel 49, is formed or secured a brake-shoe 55 for engaging that wheel to stop
its revolution. A spring 56 suitably arranged on the side of the frame 1 normally
exerts tension against the lower portion of the lever and presses the brake
against the wheel 49. Movement of this portion of the lever in direction away
from the wheel serves to free the brake and at the same time, by reason of the
angularity of the lever and its pivotal connection, swings the shaft of the driving
friction-wheel downward and brings the two friction-wheels in contact; and
thus the gearing for producing reciprocation of the saw frames is set in motion.

page_text: The lower end of the lever 53 is provided with a lug or catch 57 for engaging
a notch 58 in a horizontal bar 59, which extends to the end of the machine and is
pivoted to an arm 60 on a rocking-rod 61 mounted transversely in the lower
portion of the frame end. To this rod is attached a foot-lever 62 in convenient
position to be operated by a workman at the end of the machine. Pressure on
this foot-lever serves to actuate the bar 59 lengthwise and by engagement of the
notch 58 in the bar with the lug 57 on the lever 53, turns the latter on this
pivot sufficiently to cause contact of the two friction-wheels. It is obvious that
so long as the friction-wheels are in contact the saw-sash reciprocations would
continue; but stopping devices, operating automatically at suitable intervals are
provided to prevent such continuous reciprocatory movements.
On the shaft 42 is a disk 63 having at two diametrically opposite points pro-
jections 64 for engaging a lever 65 to depress it whenever the projections come
in contact with it. This lever is fulcrumed to a bracket 66 and its outer arm
extends beneath the longitudinal bar 59, and in position to lift it when the
inner end of the lever is depressed by the projections on the disk 63. This lifting
of the bar 59 frees its notch 58 from the catch 57 on the friction and brake lever
and thus permits the spring 56 to exert. its force against the lever to free tho.
friction and apply the brake. As the cam projections 64 are at opposite sides
of the disk it is apparent that the operation of the controlled mechanism will
continue only during a half revolution of the disk, and that the succeeding
cam engagement will depress the engaged lever and thereby actuate the brake to
stop further movement. To renew the operation the foot-lever must be released
and returned to its elevated position, which is done by the force of a spring (not
shown) connected in any well-known way. When so raised the bar 59 is again
in proper position to engage the catch in the friction-carrying lever 53 upon
depression of the foot-lever. The devices at both ends of the machine, for
controlling the reciprocations of the saws in one instance and those of the table
in the other, are substantially the same; and the same reference numbers are used
for corresponding parts in both mechanisms.
The tables 67 at the opposite ends of the machine are similar in general
structure and arrangement, the one being arranged to reciprocate vertically, and
the other to remain stationary, but adapted to be swung laterally on hinges (as
shown in Fig. 4) to give access to the saws and other interior parts. The
reciprocating table (used in connection with the dovetailing saws) is supported
by a bracket frame 68, having loose sleeves 69 on vertical guide-rods 70 that
extend from the bottom to the top of the frame 1. On the outer end of tho
shaft 42 is a crank-disc 71, and to a pin 72 thereon, and to the under side of the
table 67, a pitman 73 is connected, so that a throw of the crank will reciprocate
the table upward on the rods 70, from the position shown in Figs. 1. and 2, to a
point above the saws, where it will be stopped by the brake, by the operation of
the cam 63 on the brake connections. After a release of the foot-lever and
subsequent pressure upon it, the renewal of the crank-movement will retract the
table to its lower position, where it will be again arrested in the same manner.
The boards to be cut can be placed in proper position on the table by means
of a guide 74, that prevents lateral movement and which is adjustably laterally on
the table by set-screws 75 that pass through slots in its base; and other
guides, 76, at right angles to the former and adjacent to the saws, which limit
inward movement of the boards. The latter guides are upward tapering pro-
jections on bars 77 and are of proper size and suitably spaced to pass freely
through the interstices between the saws. These bars are of T-shape in cross-
section (Fig. 10), and are held together in a series by intermediate flat strips 78,
and underlying strips 79 that may have flanges on which the bases of the bars 77.
rest; and the strips 78 and 79 are clamped together by bolts and furnish ways
for the lengthwise movement of the guide bars 77. The whole series of bars and
strips are placed in a frame 80. The outer end of each of these bars is
adjustably secured by a set-screw 81 to a moveable cross-piece 82. Thus each

page_text: guide bar, by freeing its set-screw, may be independently removed or adjusted;
and the series may be adjusted lengthwise in unison by movement of the piece 82,
The latter adjustment is made by a screw engaging the frame 80 and bar 82 and
operated by a nut or wheel 83. The inner ends of the strips 78 are cut away,
as shown in Figs. 8 and 9, to provide projections 84 corresponding with those
remaining on the boards when the dovetails or tenons are formed; and such
projections serve as supports for the edge of the board while it is being cut to
prevent portions from being broken or torn off by the saws. The adjustable
table-section thus built up and its frame 80 are placed in a corresponding recess 85
in the table-bed 67.
Boards are held in place on the table by a clamping bar 86, suspended by
screws 87 from the cross-piece of a clamp frame 88 above the table. Ways 89
are provided to guide the ends of the bar, so that its position relative to the
table can be adjusted as desired by turning the screw 87. From the under sides
of this frame rods 90 extend downward through openings in the table and
carry springs 91 which bear against the under side of the table and against
nuts on the ends of the rods, thereby tending to draw the clamping frame down-
ward toward the table. Further movement of the table downward from the
position shown in Fig. 2 will cause the ends of the clamp frame to strike stops 92
on the frame 1, and remain stationary; while the table will descend to the limit
allowed by the throw of the pitman 73, and so the space between the clamp-bar 86
and the table will be widened to release the board for removal. Upon the upward
reciprocation similar adjustment stops 93, near the top of the frame, serve to arrest
the movement of the outer ends of levers 94, the inner ends of which are pivoted
at 95 to the frame 88 and are intermediately fulcrumed on lugs 96 on the table.
The obvious effect will be the separation of the table and clamp in the same
manner as when the clamp frame itself engages the lower stops in its downward
movement. The stops 92 and 93 are adjustable up and down to regulate the extent
of separation of the clamp and table as desired.
The table at the opposite end of the machine, where the tenons are formed, is
hinged by knuckles 97 to a rod 98, so that it may be swung to one side, as indicated
in Fig. 4. When in working position the portion of the table opposite its
hinged connection is bolted to a bracket 99, supported by a rod 100. This
bracket is hinged on the rod so that it may be swung outward when not in use,
as indicated in Fig. 4, to give better access to the interior parts. As the saws
at this end of the machine reciprocate diagonally it is necessary that the table
be in a proper plane relative to the intersections of the planes of the movements
of the saws in their reciprocations, so that the saws of the second series will pass
through the kerfs at the one surface of the board that were cut by the saws
of the first series. To enable the initial adjustment of the table to such position
to be made, a hand-wheel 101 on the rod 98; which has a screw-threaded
portion 102, may be turned to raise or lower the bed to the extent necessary; and,
afterwards, if, from wear of parts or other cause, it be found necessary to make
slight vertical adjustment of the table it may be done in the same way.
The parts having been arranged for the cutting of lumber of a given thickness,
to suitably change their position for thicker or thinner boards the table and
clamping device should be adjusted in opposite directions to an equal extent.
This is done, in reference to the clamp, by turning the screws 87; and the corre
sponding adjustment of the table is effected by the raising or lowering of the
adjustable portion, carried by the frame 80, within the table recess 85. For this
purposo cams 103 on shafts 104 journaled in bangers 105, at the under side of the
main table frame, support the adjustable table-frame 80. To these shafts are
attached arms 106 that are connected by bars 107, and to the end of one of the
shafts 104 a hand-lever 108 is attached, and is provided with a catch 109 for
locking it at any desired point of adjustment of a segment 110 projecting from
the upper portion of the frame 1. The movement of the lever-handle toward or
away from the machine serves to raise or lower the adjustable table to the

page_text: extent desired, and when the lever-handle is locked the parts will be held in
position.
For the purpose of raising the clamping-bar 86, so that boards can be freely
inserted or removed while the reciprocating saws are stationary, there is provided
an arrangement of levers to be operated by the same cam-disk 63 that serves to
stop the saw reciprocations. Upon the completion of a thrust a cam projection 64
engages the lower arm of a lever 111 that is fast to a rod 112 fulcrumed in the
machine frame and carries on it an upper angular arm 112" which bears against
the outer side of a depending lever-frame. The lower arm 113 of this frame has
the upper end of a strip 114 attached to its side, and an adjusting screw 115 for
varying tho distance of the lower end of the strip from the arm, to regulate the
extent of the inward movement of the arm 113 caused by the throw of lever 112ª.
The lever 113 is fulcrumed to the table frame at 116 and has a lateral arm. 117.
A bar 118 lias one end pivoted to the lever 113 and its other end pivoted to the
lower arm of a lever 119 that is fulcrumed to the table frame at 120 and has a
lateral arm 121 on a level with the arm 117 of the lever 113. It is apparent that
depression of the lower end of the lever 111 will swing the upper arm 112 inward'
and thereby rock the connected levers 113 and 119 on their fulcrums and corre-
spondingly elevate their lateral arms 117 and 121. To utilize such movements for
lifting the clamp from the board, pins 122, secured on the under side of the clamp
frame 88, are extended downward through holes in the table to points whero
they are engaged by the lever arms 117 and 121 in their upward movements and
the clamp frame is thereby lifted. In normal position the clamp frame rests in
seats 123 on the table bed.
Tho saws 33, their frames 34 and 36, and the connected reciprocating parts
are counterpoised by a weight (not shown) attached to the lower end of a rope 124,
which runs over a grooved pulley 125 at the top of the machine, and is connected
to the frame 34 or 36: whereby the work of the driving crank 41 is lessened.
To maintain uniform distance between the saw arbors and the shafts that drive
them, during the vertical reciprocations of the former, radius-rods 126 are con-
nected at their outer ends to the saw-frames and at their inner ends by forked
arms 127 to the sides of the swinging frames 128 and 129; respectively,
upon which the shafts 16 and 17 are journaled. The lower portions of the
frames 128 and 129 are hinged, at 130 and 131 respectively, to inner parts of
the machine, frame, and as their upper portions are pivotally connected, at 132
and 133, to the arms of the radius-rods, they are capable of rocking movements,
while the rods serve to maintain an unvarying distance between the parts they
connect.
To cut tenons, a board having been placed on the table with a latteral edge
against the guide 74, and the inner edge against the guides 76, the clamp bar.86
being at the time in its elevated position and the saws at one or the other of
their extremes of movement, a depression of the foot-lever 62 will free the
brake and bring the friction pulleys in contact and start rotation of the shaft 42.
The first operative effect of such rotation is to move the cam 64 from contact
with the lever 111 and allow it to rise to contact with the face of the disk 63,
which movement permits the springs 91 to pull the clamp-frame downward and
clamp the board on the table. Further rotation of the shaft 42 will reciprocate
the saws in their diagonal courses and cause them to cut tenons with beveled sides,
each tenon being separately supported at the under side and protected from being
broken or torn by the saws by means of one of the projections 84 or a guide-
bar 77. When the limit of a reciprocation is reached the second cam 64 will
liave engaged the levers 65 and 111, and the actuation of the former lever will
cause the separation of the friction wheels and application of the brake, and the
actuation of the latter lever serve to lift the clamp from the board.
To form the dovetail mortises the board is placed on the other table, and guided
and supported in the same manner. Upon depression of the foot-lever the brakė
is released and the friction wheels brought together, thereby starting the rotation

page_text: of the crank-shaft and the reciprocation of the table, the immediate effect of
which is to release the clamp-frame from the stops 92 or 93 and permit the
clamp-bar to descend to the board and hold it in place. As the table approaches
the limit of its reciprocation the stops 92 or 93 are again engaged and the
clamp-bar lifted; and coincidently one of the cams 64 depresses the lever 65
and the movement of the latter releases the foot-lever connection with the brake-
lever and permits the brake to be applied to the friction wheel to stop the
operating machinery and hold it in place for the removal of the board.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. In a dovetailing machine, the combination with a stationary work-holder,
of arbors carrying sets of cutters, means for rotating the arbors, means for
reciprocating them in intersecting courses on a common plane, and devices operat-
ing automatically upon the completion of each reciprocatory movement to prevent
a return reciprocation, substantially as set forth.
2. In a dovetailing machine, the combination with a stationary work-holder,,
of guides arranged in intersecting diagonal courses, sliding frames therein, cutter-
arbors mounted on the frames, means for rotating the arbors, means for recipro-
cating the frames in the guides, and means for automatically arresting their move-
ments at the end of each reciprocation; substantially as set forth.
3. In a dovetailing machine, the combination with a stationary work-holder,
of guides arranged in intersecting diagonal courses, sliding frames therein con-
nected to move in unison, cutter-arbors mounted on the frames, means for
rotating the arbors, a crank for reciprocating the cutter frames, and devices
operating automatically to stop the crank at each extreme of its throw, sub-
stantially as set forth.
4. In a dovetailing machine, two reversely arranged series of guides set at
angles corresponding to the angles of the dovetails and in which frames are
adapted to be moved in unison, shafts journaled upon said diagonal frames and
carrying cutters and adapted to be revolved, a stationary table adapted to support
the material to be acted upon, and devices for holding the cutter-carrying frames
stationary upon completion of each reciprocation, substantially as set forth.
5. In a dovetailing machine, diagonal guides, connected sliding frames therein,
cutter-carrying arbors mounted on the frames and provided with means for
rotating them, a shaft and crank and connections for reciprocating the frames,
controllable friction devices for causing the shaft to rotate, and automatic brake
devices for stopping it at each half turn, substantially as set forth.
6. In a dovetailing machine, series of circular saws of equal diameters on
angularly arranged rotating arbors, sliding frames therefor in guides at right
angles to the arbors, a table adapted to hold boards in proper relation to the plane
of intersection of the cutter reciprocations for the cutting of bevel-faced tenons,
mechanisin under control of an operator for causing a reciprocation of the cutters
past the table, and automatically operating devices for stopping such mechanism
upon completion of each reciprocation of the saws, substantially as set forth.
7. In a dovetailing machine, the combination with connected cutter-carrying
frames arranged to travel in diagonal courses, and a work-holder suitably fixed
relative to the travel of the saws; of a pitman and crank for reciprocating said
frames, gearing including a friction wheel for intermittently rotating the axis
of the crank, a driving friction wheel mounted on a movable support, an operating
lever and connections for moving the latter friction wheel to contact with the
former, and a brake meclianism operating automatically to separate the friction
wheels and apply the brake to the idle friction wheel at each half revolution
of the crank, substantially as set forth.
8. In a dovetailing machine, the combination with the driving gear for
reciprocating the saw frames or table, of friction wheels for communicating

page_text: motion thereto, a rocking frame carrying the driving friction, a brake arranged
thereon to engage the idle wheel when the running wheel is freed therefrom, a
spring for rocking the frame to apply the brake, an operating lever and con-
nections for rocking the frame to release the brake and bring the friction wheels
to contact, and a tripping lever operated periodically by said driving gear to
disconnect the operating lever and rocking frame and permit the brake spring
to rock the latter and apply the brake substantially as set forth.
9. In a dovetailing machine, diagonal guides, connected sliding frames therein,
rotary cutter-carrying arbors mounted thereon, driving gear for reciprocating the
frames, friction wheels for communicating motion to such gear, a rocking frame
carrying the driving friction wheel, a spring-actuated brake on the same frame
arranged to engage the idle wheel, upon release therefrom of the driving friction
wheel, and an operating lever and connections adapted to rock said frame to
release the brake and cause contact of the friction wheels, substantially as set
forth.
10. In a dovetailing machine, diagonal guides, connected sliding frames
therein, rotary cutter-carrying arbors mounted thereon, driving gear for recipro-
cating the frames, friction wheels for communicating motion to such gear, a
rocking fame carrying the driving friction wheel, a spring-actuated brake on the
same frame arranged to engage the idle wheel upon release there-
from of the driving friction wheel, an operating lever and connections
adapted to rock said frame to release the brake and cause contact of the
friction wheels, and a tripping device operated automatically by the driving gear
to release the lever connection with the rocking frame and permit the brake spring
to rock the latter to free the friction wheels and apply the brake, substantially as
set forth.
11. In a dovetailing machine, the combination with diagonal guides, sliding
frames therein, cutter-arbors mounted thereon and means for reciprocating the
frames in the guides, and mechanism for reciprocating the frames in their guides;
of pulleys and belts for rotating the arbors, rocking frames for mounting the
pulleys, and radius-rods pivotally connecting the latter frames and the sliding
frames, for the purpose set forth.
12. In a dovetailing machine, the combination with a stationary table and
devices for clamping the material thereon, of guides arranged in intersecting
diagonal courses, sliding frames therein, cutter-arbors mounted on the frames,
means for rotating the arbors, means for reciprocating the frames in the guides,
means for automatically arresting their movements at each reciprocation, and
means for coincident automatic release of the clamp from the material, sub-
stantially as set forth.
13. In a dovetailing machine, the combination with a stationary table and
clamping device for holding boards in place thereon, of guides and cutter-carrying
frames therein, mechanism for reciprocating said frames to cause the cutters to
engage the boards, and automatic devices actuated by said reciprocating
mechanism to release. the clamp after the cutters have passed the board, sub-
stantially as set forth.
14. In a dovetailing machine, the combination with a stationary table and
clamping devices for holding boards in place thereon, of guides and cutter-
carrying frames therein, mechanism for reciprocating said frames to cause the
cutters to engage the boards, a system of levers for lifting the clamp from the
board and a cam operated by said mechanism to actuate said levers as the com-
pletion of each reciprocation is neared, substantially as set forth.
15. In a dovetailing machine, the combination with a stationary table and
clamping devices for holding boards in place thereon, of guides and cutter-
carrying frames therein, mechanism for reciprocating said frames to cause the
cutters to engage the boards, a system of levers for lifting the clamp from the
board, a cam operated by said reciprocating mechanism to actuate said levers as
tlio completion of each reciprocation is neared; and brake devices arranged to be

page_text: coincidently set in operation by the same cam movement to stop the reciprocating
mechanism, substantially as set forth.
16. In a dovetailing machine, the combination with a table, of a clamp-frame
loosely seated thereon, a clamping-bar adjustably supported centrally to the
frame, springs for drawing the frame toward the table while the board is being
cut and devices arranged to automatically lift the frame after the cutting is
completed, substantially as set forth.
17. In a dovetailing machine, the combination with the main frame, diagonal
guides and reciprocating cutter carriers, of a table frame, and an upright rod
having a screw-threaded portion and arranged to vertically adjust and pivotally
support the table frame to allow it to swing laterally, substantially as set forth.
18. In a dovetailing machine, the combination with a table, of a clamp frame
thereon supporting a vertically adjustable clamping bar, and a vertically adjust-
able table-section underlying said bar, whereby variations of the space between
the clamp and board-support may be apportioned as desired above and below a
selected plane, substantially as set forth.
19. In a dovetailing machine, the combination with a table, of a superposed
clamp-frame, a clamping-bar guided vertically in the frame, and means for
adjusting the position of the bar relative to the frame, substantially as set forth.
20. In a dovetailing machine, the combination with a table, of a superposed
clamp-frame, a clamping-bar guided vertically in the frame, and means for
adjusting the position of the bar relative to the frame, and springs for drawing
the clamp-frame toward the table, substantially as set forth.
21. In a dovetailing machine, a table having a central recess, a supplemental
table therein, and devices for adjusting it vertically in the recess, for the purpose
set forth.
22. In a dovetailing machine, a table having a central recess, a supplemental
table therein, and devices for adjusting it in the recess toward or away from the
cutters, substantially as set forth.
23. In a dovetailing machine, the combination with a main table having a
central recess, of a supplemental table section therein providing a series of guides
and tongues for supporting the board edge while it is being cut, substantially
as set forth.
24. In a dovetailing machine, a table portion for supporting and guiding boards,
and providing a series of rods having up-turned ends forming guides for the
edge of the board between the cutters and supports for its under side, substantially
as set forth.
25. In a dovetailing machine, a table portion for supporting and guiding
boards, and providing a series of rods having up-turned ends forming guides for
the edge of the board between the cutters and supports for its under side, and a
series of intermediato projections underlying the tenons to support and protect
them from the cutters, substantially as set forth.
26. In a dovetailing machine, a table portion for supporting and guiding
boards, and providing a series of rods having up-turned ends forming guides for
the edge of the board between the cutters and supports for its under side, and a
series of intermediate projections underlying the tenons to support and protect
them from tho cutters, said table portion as a whole and also said guide rods
separately being longitudinally adjustable, substantially as set forth:
27. In a dovetailing machine, the combination with sets of cutters of unequal
diameters on obliquely arranged rotary arbors mounted in stationary bearings, of
a table, mechanism for reciprocating it on a plane past the cutters, and devices
for automatically stopping and holding it at the end of each reciprocation,
substantially as set forth.
28. In a dovetailing machine, the combination with sets of cutters of unequal
diameters on obliquely arranged rotary arbors mounted in stationary bearings,
of a table, devices for clamping boards thereon; means for reciprocating the table
past the cutters, means for automatically stopping it at the end of each recipro

page_text: cation, and automatic devices for releasing the clamping devices coincidently with
the stoppage of the table movements, substantially as set forth.
29. In a dovetailing machine, the combination with rotary cutters on stationary
supports, of a reciprocating table, a clamp-carrying frame loosely mounted
thereon, and devices for lifting the clamp frame from the table as the latter
nears the limits of its reciprocating, movements, substantially as set forth.
30. In a dovetailing machine, the combination with rotary cutters on stationary
supports, of a reciprocating table, a clamp-carrying frame loosely mounted
thercon, and stops for arresting its downward movement before the table reaches
its lower limit of travel, whereby the distance between the clamp and table
is increased, substantially as set forth.
31. In a dovetailing machine, the combination with rotary cutters on stationary
supports, of a reciprocating table, a clamp-carrying frame loosely mounted
thereon, levers, pivoted and fulcrumed thereon, and stops near the top of the
machine frame for engaging such levers, to lift the clamp frame as the table
nears its upper limit of reciprocation, and thereby increase the distance between
the clamp and table, substantially as set forth.
32. In a dovetailing machine, the combination with rotary cutters on stationary
supports, of a table, vertical guides therefor, a shaft and crank and connections
for reciprocating the table, friction-wheels controlled by an operating lever for
starting the shaft rotations, and automatic brake devices for stopping them at
each half turn, substantially as set forth.
33. In a dovetailing machine, the combination with rotary cutters on stationary
supports, of a reciprocating table, devices carried thereon for clamping boards
to the table, and means operating automatically to lift the clamp from the board
as the table nears the ond of a reciprocation and to permit it to again engage
the board as the table begins another reciprocation, substantially as set forth.
34. In a dovetailing machine, the combination with reciprocating cutter-
carriers, of a stationary table, devices thereon for clamping boards to the table,
and means operating automatically to lift the clamp from the board as the cutter-
carriers near the end of reciprocation and to permit it to again engage the
board as the cutters begin another reciprocation, substantially as set forth.
35. In a dovetailing machine, rotary cutlers, a table and devices for clamping
boards thereon, means for reciprocating the table past the cutters or the cutters
past the table, means for starting such movements at will, devices operating
automatically to stop the reciprocatory movements at the end of each reciprocation,
and automatically operating devices for clamping boards to the table during such
reciprocations and releasing them coincidently with the ending of reciprocations,
substantially as set forth.
Dated 118 29th day of May 1899.
JOHN EMILL ERICKSON.
Marks & Clerk,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester,
Agents.