An Improved Envelope Folding Machine.
Year: 1890

page_text: Date of Application, 2nd Dec., 1890
Complete Specification Left, 18th Mar., 1891-Accepted, 2nd May, 189
PROVISIONAL SPECIFICATION.
An Improved Envelope Folding Machine.
I CARL WILHELM FRIEDRICH THODE of Hamburg in the Empire of Germany
Manufacturer do hereby declare the nature of this invention to be as follows:-
This invention relates to an improved envelope-folding machine, and has for its
object to enable the machine to be adapted to fold envelopes of different sizes
without dismounting any of the parts.
Upon the table of the machine are mounted four shafts arranged in the form
of a parallelogram with each side produced at one end and the parallelogram
corresponding to the envelope when folded. The shafts are in section square
with the arrises bevelled, the latter forming the journal surfaces turning in the
bearings, whilst the parts carried by the shafts fit upon the flats so as to rotate
with the shafts with freedom, for longitudinal adjustment thereon. Each shaft
turns in three bearings of which the middle one also supports the inner end
of the shaft normal thereto, and, to enable the size and shape of the parallelo-
gram to be varied, certain of these bearings are adjustable in position
on the
table by means of guide slots and clamping screws, the arrangement being such
that the form of the parallelogram will always be maintained. A scale is
provided on the table to facilitate this adjustment. Upon the parts of the shafts
forming the sides of the parallelogram are mounted folding lappets which turn
with the shafts and which also serve to prevent the shafts sliding in their
bearings. On each shaft is mounted a double grooved sheave through which
the shafts are free to slide and by which they are operated. For this purpose
the sheaves of the one parallel pair of shafts are connected by cords with one
of two treadles whilst the sheaves of the other pair of shafts are similarly con-
nected with the other treadle. By depressing these treadles, the shafts receive
a semi-revolution in one direction, the reverse motion being imparted by springs
respectively connected to the same pulleys by cords passing over the pulleys in
the opposite direction to the treadle cords the springs corresponding to those
pulleys whose positions on the table are variable being movable therewith. A
counterweighted hand lever is pivoted at the back of, and extends over, the
table and is laterally adjustable so as to pass centrally over the parallelogram
formed by the folder shafts. This lever carries a pair of cross-bars adjustable
longitudinally thereon and to which are affixed downwardly extending knife-
edged pressers adjustable laterally along the cross-bars so that their position
may be made to correspond exactly to the intended lines of the top and bottom
folds. To the hand lever are bolted a pair of crossed slotted bars disposed
✗-wise to which are bolted a pair of adjustable gum-troughs of V-section
furnished with sponges by which the adhesive material is deposited at the proper
places along the edges of the bottom flap of the envelope.
The operation of the machine is as follows:-The hand lever being raised the
envelope blank already cut to shape and gummed at the top or seal Hap is placed
upon the table in such position that when the hand lever is brought down the knife
edged pressers will come down on and depress the paper slightly, exactly along the
lines of the top and bottom folds the outermost corners of the pressers coinciding
also with the lines of the side folds at the same time that the gummer deposits the
adhesive material along the edges of the bottom flap. The hand lever being
held down, the one treadle is depressed whereby the folders carried by the one pair
of shafts are turned over so as to fold the side flaps of the envelope. The treadle
being kept depressed in order to hold the partially-folded envelope in position, the
lever is then raised and the other treadle also depressed whereby the folders carried

page_text: by the other pair of shafts are similarly operated for the purpose of folding the top
and bottom flaps, the folder which folds the bottom flap being operated slightly
before the other, in order that the bottom flap, on which the adhesive material is
still moist, may be pressed firmly on the side flaps before the seal flap is folded.
Both treadles are then released and the finished envelopes are removed and the
parts are returned by the counterweights and springs to their original position for
the next envelope. The operation of the bottom folder in advance of the upper one
is arranged for by making the cord corresponding to the former a little tighter than
the other, both these cords being attached to a pivoted arm fixed adjustably to a
quadrant fixed to the treadle so as to be adaptable to the variable position of the
sheaves to which the cords run.
Gum troughs are fixed adjustably to horizontal slotted cross bars adjustable to
suit the shape of the sealing flap and attached to a cross-bar vertically guided in a
frame. The gum troughs rest upon the sealing flap of the uppermost of the pile of
envelope blanks which are withdrawn successively, the gummer coming down on
each in succession and preventing any disturbance of the underlying pile of blanks.
Dated December 2nd 1890.
COMPLETE SPECIFICATION.
An Improved Envelope Folding Machine.
I, CARL WILHELM FRIEDRICH THODE of Hamburg in the Empire of Germany,
Manufacturer, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement :-
This invention relates to an improved envelope-folding machine, and has for its
object to enable the machine to be adapted to fold envelopes of different sizes
without dismounting any of the parts, when the dimensions of the envelope are to
be altered.
Upon the table of the machine are mounted four shafts arranged in the form
of a parallelogram having each side produced at one end, the parallelogram
corresponding to the dimensions of the envelope when folded. The shafts are
in section square with the arrises bevelled off, the bevels forming the journal
surfaces turning in the bearings, whilst the parts carried by the shafts fit upon
the flaps so as to rotate with the shafts with freedom for longitudinal adjustment
thereon. Each shaft turns in three bearings of which the middle one also
supports the inner end of the shaft normal thereto, and, to enable the size and
shape of the parallelogram to be varied, certain of these bearings are adjustable
in position on the table by means of guide slots and clamping screws, the
arrangement being such that the form of the parallelogram will always be
maintained. A scale is provided on the table to facilitate this adjustment.
Upon the parts of the shafts forming the sides of the parallelogram are
mounted folding lappets which turn with the shafts and which also serve to
prevent the shaft sliding in their bearings. On each shaft is mounted a double
grooved sheave through which the shafts are free to slide, and by which they
are operated. For this purpose the sheaves of the one parallel pair of shafts
are connected by cords with one of two treadles whilst the sheaves of the other
pair of shafts are similarly connected with the other treadle. By depressing
these treadles, the shafts receive a semi-revolution in one direction, the reverse
motion being imparted by springs respectively connected to the same pulleys
by cords passing over the pulleys in the opposite direction to the treadle cords,
the springs corresponding to those pulleys whose positions on the table are
variable being movable therewith. A counterweighted hand lever is pivoted at
the back of, and extends over, the table and is laterally adjustable so as to

page_text: pass centrally over the parallelogram formed by the folder shafts. This lever
carries a pair of cross bars adjustable longitudinally thereon and to which are
affixed downwardly-extending knife-edged pressers adjustable laterally along the
cross-bars so that their position may be made to correspond exactly to the
intended lines of the top and bottom folds. To the hand lever are bolted a
pair of crossed slotted bars disposed ✗-wise, to which are bolted a pair of
adjustable gum troughs of V-section furnished with sponges by which the
adhesive material is deposited at the proper places along the edges of the bottom
flap of the envelope.
Reference is to be had to the accompanying drawings, forming part of this
Specification, in which Figure 1 is a front elevation, partly in section, Figure 2 is a
side-sectional elevation, Figure 3 is a plan, and Figure 4 a plan, (with the hand
lever removed) of the machine. Figures 5 and 6 are detail views. Figures 7, 8, 9,
shew the apparatus for gumming the seal flaps.
.A. is the table of the machine which is recessed in a frame mounted on standards
and carrying four shafts a¹ a² a³ a (shewn in cross-section on a larger scale in
Figures 5 and 6) of square section with the arrises bevelled off to form the
journal surfaces of the shafts in their bearings whilst the parts rotating with the
shafts fit against the flats, as shewn in Figure 6. The shaft a¹ turns in fixed
bearings 62 and an intermediate adjustable bearing d'. The shaft a turns in the
fixed bearings e ₁, its end journal being supported in the adjustable bearing c¹.
The shaft a runs in the bearings c c² 3 whilst the shaft a' runs in bearings d' d² c³.
The adjustable bearings are so guided as to be only movable in a direction
parallel or normal to the shafts. The bearing consists of two slide blocks
fitted in parallel slots in the table A. and secured by a screw c in the slot c.
Bearing is carried by a slotted plate secured by screw 1 inserted in one of
the holes f. The bearing slides in the slot d³ and bearing d² slides in slot d*.
The bearing c is carried by a slotted plate, secured and guided by two bolts y¹
passing through slots in the table.
In order that all the parts may always be accurately adjusted at right angles
to one another, the part of the table where the work is done is provided with a
scale divided in inches, centimetres, etc., as required. To make envelopes of a
certain size it is simply necessary that the space enclosed by the four shafts be made
to correspond to the size required, which may be accurately done by means of the
scale.
Upon the shafts a¹ a² a3 at between the bearings c¹ c³ d¹ are mounted the
folding lappets whose bosses fit on the shafts so as to turn therewith. The
middle folders h may be regarded as filling pieces whilst the end folders' of
each set are fixed to the shafts by binding screws and prevent longitudinal
movement of the shafts in their bearings. Each shaft carries a double grooved
pulley k¹ k² ka khaving a square hole fitting on the shaft, as shewn in Figure 6,
so as to revolve the shafts and folders whilst permitting sliding motion of the
shafts through the pulleys for the purpose of adjustment. The pulleys are driven
as follows: CD are treadles pivoted on a cross-bar B. The treadle D has a
cross rod E whilst the treadle C has a standard F upon which is pivoted a
swinging arm F movable over the quadrant F¹ also fixed on the standard. Two
cords attached to the ends of the rod E run to the sheaves k³ ³ respectively and
two others run from the arm F2 to the sheaves, the ends of the cords being
attached to the sheaves, the cords of each pair leading from the sheaves in such
manner that when the treadle is depressed the corresponding pair of sheaves will
be rotated in contrary directions so as to turn inwards the folders upon the shafts
operated by those sheaves. The treadle C operates the shafts a³ a and the
treadle D operates the shafts a' a². The contrary motion whereby the folders are
turned outwards, is a second cord leading off the other pulley groove in the opposite
direction to the first cord attached to each of the sheaves k₁ k² k³ k*, the other
ends of the cords being attached to springs 11 12 13 14 which are put in tension
when the treadles are depressed. As the position of the sheaves and in the

page_text: table varies, the arm F2 is free to swing to accomniodate itself to the position of
and the holders of their springs 12 14 are fixed to the bottom of the respective
bearings c and d with which they move. and are guide sheaves for the cords.
G is a hand lever pivoted on a shaft m at the rear of the frame, extending to the
front of the machine and slotted to receive the bolts of channelled cross-bars n¹ n²
fixed adjustably thereon. A pair of knife-edged pressers pl p² are fixed in the
groove of each of the cross-bars by means of screws. Two slotted bars r¹² are
fixed cross-wise beneath the lever G by a bolt K which serve to hold gum
troughs 3 by which the bottom flap is gummed, the gum exuding through the
sponges at the lower edge of the reservoirs 73. The tail end of the lever G is
counterweighted at m² and is adjustable upon shaft m and the pressers p² p² are
adjustable along the cross-bars n² n².
The operation of the machine is as follows:-The hand lever G being raised,
the envelope blank, already cut to shape and gummed at the top or seal flap, is
placed upon the table A in such position that when the hand lever G is brought
down the knife edged pressers p₁ p² will come down on, and depress, the paper
slightly exactly along the lines where the top and bottom folds are to be made,
the outermost corners of the pressers coinciding also with the lines of the side folds
at the same time that the gummer deposits the adhesive material along the edges
of the bottom flap. The hand lever G being held down, the treadle C is depressed
whereby the folders carried by the pair of shafts a³ a' are turned over so as to fold
inwards the side flaps of the envelope. The treadle C being kept depressed in
order to hold the partially-folded envelope in position the lever G is then raised
and the other treadle D also depressed whereby the folders carried by the other
pair of shafts a¹ a² are similarly operated for the purpose of folding the top and
bottom flaps, the folder on shaft a² which folds the bottom flap being operated
slightly in advance of the other by making the cord which connects sheave k² to
rod E somewhat tighter in order that the bottom flap on which the adhesive
material is still moist may be pressed firmly on the side flaps before the seal
flap is folded. Both treadles are then released and the finished envelope removed,
and the parts are returned by the counterweight and springs to their original
position for the next envelope.
The gumming of the seal flap is effected by means of the apparatus shewn in
Figures 7, 8, and 9, connected directly or indirectly with the machine. The cross-
bar has ends s¹ sliding in the slotted uprights s and is slotted to receive the bolts
for holding the gum reservoirs. In Figure 8 the flap to be gummed has a penta-
gonal shape and a central reservoir » is bolted to bar t and at either side of it, two
slotted barst are pivoted to said bar t by bolts t² to each of which a wedge-shaped
reservoir ¹ is attached, these pivoted carriers being adjustable to suit the shape of
the flap. The gum troughs rest upon the scaling flap of the uppermost of the pile
of envelope blanks which are withdrawn successively, the gummer coming down
on each in succession and preventing any disturbance of the underlying pile of
blanks. The gum reservoirs can be readily changed for others of a different shape
if required.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is--
The herein described envelope folding machine wherein the folder shafts a¹ a² a³ a¹
are arranged as described and turn in fixed and adjustable bearings in combination
with the laterally-adjustable hand lever carrying the pressers and gum holders, all
substantially as specified.
Dated this 17th day of March 1091.
C. W. F. THODE.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
re
C. W. F. THODE.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.