U.S. patent number 3,850,470 [Application Number 05/387,917] was granted by the patent office on 1974-11-26 for expandable housing unit.
Invention is credited to Roy Kay Trelle.
United States Patent |
3,850,470 |
Trelle |
November 26, 1974 |
EXPANDABLE HOUSING UNIT
Abstract
An expandable housing unit which has an upper housing section
mounted for telescopic extension and retraction over a lower
housing section, and drawers which are mounted in each side of the
lower housing section for lateral movement between the extended and
retracted positions when the upper housing member is raised. The
drawers are fitted with vertically moveable roof sections which are
normally in a retracted position when the upper housing member is
in the lowered position and which are spring-urged upwardly so as
to follow the upper housing member as the latter is raised.
Inventors: |
Trelle; Roy Kay (Burnaby,
British Columbia, CA) |
Family
ID: |
23531841 |
Appl.
No.: |
05/387,917 |
Filed: |
August 13, 1973 |
Current U.S.
Class: |
296/175; 52/66;
296/165; 296/26.02; 49/425 |
Current CPC
Class: |
B60P
3/32 (20130101) |
Current International
Class: |
B60P
3/32 (20060101); A47f 013/06 () |
Field of
Search: |
;296/26,23R,23C,23MC,27
;49/425 ;312/296 ;52/66,67 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Reeves; Robert B.
Assistant Examiner: Skaggs, Jr.; H. Grant
Attorney, Agent or Firm: Carver and Company
Claims
I claim:
1. An expandable housing unit including:
a. a roofless lower housing section having four walls and a
floor,
b. a roofed upper housing section having four walls mounted over
the lower housing section for telescopic movement a raised position
and a lowered position,
c. means for moving the upper housing section between said
positions,
d. an opening in at least one wall of the lower housing section
extending substantially from end to end thereof,
e. a drawer having end walls mounted in the opening,
f. a roof section over the drawer lying below and clear of the
lower edge of an adjacent wall of the upper housing section when
the latter is fully raised,
g. means for mounting the drawer for movement between a retracted
position within the lower housing section and an extended position
projecting outward therefrom with said means including:
i. a rail having an inboard portion secured to an end wall of the
lower housing section,
ii. and having an outboard portion hingedly connected to the
inboard portion for swinging movement between a substantially
vertically upstanding position co-extensive with the inboard
portion,
iii. an elongated support member secured to an adjacent end wall of
the drawer for engaging the rail and supporting the drawer
thereon,
iv. a plurality of rollers mounted on the support member for
movement between the retracted positions above the support member
and extended positions extending below the support member for
engagement with the rail so as to provide rolling support for the
drawer on the rail and,
v. manually operative means for moving the rollers between said
positions.
2. An expandable housing unit as claimed in claim 1 in which the
means for moving the rollers between extended and retracted
positions include:
a. a yoke for each roller pivotally mounted substantially
intermediately between its ends having an axle at a lower end on
which each roller is mounted,
b. an operating rod having a pivotal connection at the upper end of
each of the yokes,
c. a lever hingeably mounted at outer end of the support member and
having a pivotal connection with the operating rod for pivoting the
yokes so as to move the rollers between the extended and retracted
positions.
3. An expandable housing unit as claimed in claim 2 in which the
yokes move through an over center position when the rollers are
moved between their extended and retracted positions and including
stop means for limiting the movement of the yokes when the rollers
reach the extended positions so as to releaseably lock the rollers
in said extended positions.
4. An expandable housing unit including:
a. a roofless lower housing section having four walls and a
floor,
b. a roofed upper housing section having four walls mounted over
the lower housing section for telescopic movement between a raised
position and a lowered position,
c. means for moving the upper housing section between said
positions,
d. an opening in at least one wall of the lower housing section
extending substantially from end to end thereof,
e. a drawer having end walls mounted in the opening,
f. a roof section over the drawer mounted for telescopic movement
between raised and lower positions and,
g. resilient means operable independently of position of the drawer
relative to the upper housing section for yieldably urging the roof
section of the drawer upwards against the upper housing section so
that said roof section automatically follows said upper housing
section as the latter is moved between its raised and lowered
positions,
h. means for mounting the drawer for movement between a retracted
position within the lower housing section and an extended position
projecting outward therefrom.
5. An expandable housing unit as claimed in claim 4 in which means
for raising and lowering the roof section of the drawer
include:
a. pulley means mounted adjacent the upper edge of an end wall of
the drawer,
b. a cable means passing over the pulley means and connected to the
lower edge of an end wall of the roof section,
c. a preloaded spring urged mechanism connected to the cable means
for moving the roof section of the drawer to its raised position
when the upper housing section is raised and yieldably permitting
return of the roof section to its lowered position under the weight
of the upper housing section when the latter descends to its
lowered position.
6. An expandable housing unit as claimed in claim 5 in which the
preloaded spring urged mechanism includes:
a. a lever mounted adjacent one end on an end wall of the drawer
for swinging movement and connected at an opposite end to the cable
means,
b. a preloaded spring connected at one end to the lever at
substantially the midlength thereof for urging the lever to rotate
in a direction to apply tension on the cable means.
7. An expandable housing unit as claimed in claim 6 in which the
cables and lever are disposed so that the internal angle between
the cables and lever increases from an acute angle to substantially
a right angle as the drawer roof is moved from its raised position
to its lowered position so as to reduce effective lever advantage
on the spring so that the tension on the cables remains
substantially the same throughout movement of the drawer roof
between its raised and lowered positions.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to expandable housing units and in
particular, but not limited, to housing units which are carried in
the box of a truck -- the combined unit being normallly termed a
camper.
2. Prior Art
In transportable housing units of the house trailer and camper
types, particularly the latter type, provision of adequate floor
space and head room is a major concern. The shift of the effective
center of gravity due to wind resistance, side and front, dictates
to a large measure, the overall dimensions of the housing unit.
In order to minimize wind resistance when the unit is being
operated on the road and yet to provide adequate habitable space
when the unit is used for accommodation, a number of configurations
have been devised whereby the housing unit can be contracted for
travel and expanded when used for accommodation.
In one type of configuration, the housing unit has an upper roof
section which fits over a lower section for telescopic movement
between raised and lowered positions so as to provide adequate head
room when the unit is used for accommodation and also provides a
minimal frontal and side area to minimize wind resistance when
travelling. This type of unit also includes drawers in which beds
and like pieces are built, which can be moved outwards from a
contracted position within the body of the unit to an extended
position so that substantially the entire floor of the unit is
clear when the unit is set up for accommodation.
In previous drawer type units, drawers are provided with roofs
which may be canvas or wood and which usually have a connection,
hinged or otherwise to the upper edge of the drawer. The roof
elevation is therefore limited by the height of the drawer which is
normally below eye level when the camper is expanded. Consequently
head room within the drawers is insufficient and can engender a
claustrophobic effect.
Drawer type units of prior art often prove difficult to arrange in
the expanded and contracted conditions, particularly in respect of
moving the drawers between the extended and retracted positions.
Also considerable time is required to erect and fasten drawer roofs
and effect proper seals between relatively secureable parts to
ensure that the unit is sustantially proof against the
elements.
SUMMARY OF THE INVENTION
The present invention provides a portable housing unit particularly
adapted to, but not restricted to, use as a camper which is of the
expanding and contracting drawer type, which can be disposed easily
in the expanded condition, and is substantially weatherproof when
expanded. The unit is constructed to provide sufficient head room
within the unit, and drawers themselves, so necessary for
comfortable living.
The portable housing unit of the present invention has a lower
housing section, an upper housing section mounted over the lower
section for telescopic movement between the raised and lowered
positions, confronting openings in adjacent side walls, a drawer
mounted for movement between a retracted position within the lower
section and an expanded condition extending laterally therefrom,
and a roof on the drawer normally disposed beneath the upper
section when the latter is in its lower position and clear of the
side wall edges of the upper section when the latter is in the
raised position.
In one embodiment of the invention the drawer roof is mounted for
vertical movement on the drawer so that the roof can be raised and
lowered when the upper housing section of the unit is raised and
lowered.
In another embodiment of the invention the roof of the drawer is
fixed relative to the drawer.
In the description following, the drawings merely show and the
detailed description merely describes preferred embodiments of the
invention which, however, is capable of expression in structure
other than that particularly described and illustrated.
DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a camper unit including a truck,
and one embodiment of a housing unit of the invention in a
contracted condition,
Fig. 2 is a perspective view of the housing unit in an expanded
condition,
Fig. 3 illustrates, diagrammatically, mechanism for raising and
lowering the upper housing section of the unit,
Fig. 4 is a transverse sectional view of the housing unit in a
contracted condition,
Fig. 5 is a view similar to FIG. 4 of the housing unit in an
expanded condition,
Fig. 6 is a longitudinal sectional view of support mechanism for
enabling movement of a drawer,
Fig. 7 is a section taken on line 7--7 of FIG. 6,
Figs. 8, 9, and 10 are sections taken on lines 8--8, 9--9 and
10--10, respectively, of FIG. 2 illustrating sealing
arrangements,
Figs. 11 and 12 are views similar to FIGS. 4 and 5 of another
embodiment of the invention.
DETAILED DESCRIPTION
Referring to the drawings, and in particular to FIG. 1, one
embodiment 10 of a transportable expandable housing unit of the
invention is shown mounted on a pickup truck 11 which can,
obviously, be any type of truck or conveying vehicle. The truck,
conventionally, has a substantially rectangular box 12 having side
panels 13--13 and a hinged tailgate 14.
The housing unit 10, refer to FIGS. 1 and 2, has a roofless lower
housing section 15 having a lower portion 16 which fits the truck
box -- space being provided for fender clearance, see FIGS. 4 and
5, -- and a rectangular upper portion 17 which is the same length
as the lower portion but is wider than the latter so as to extend
over the side panels of the truck box. Left and right side walls 21
and 22, of the housing section 15 terminate at the juncture of the
portion 16 and 17. Front and rear end walls 23 and 24 of the lower
housing section 15 are of equal height and thus bound left and
right openings 25 and 26, see FIG. 3, into the upper portion
17.
A roofed upper housing section 27 is mounted over the lower housing
section for telescopic movement between a lowered position, as seen
in FIG. 1, and a raised position, as seen in FIG. 2. Left and right
side walls 31 and 32 and front and rear end walls 33 and 34 are of
the same depth.
Movement of the upper housing section between its raised and
lowered positions is effected by operation of the worm type winch
36, see FIG. 3, which is located in the right hand space between
the right side of the lower portion of the lower housing section
and the right side panel of the box and it is operated by a crank,
not shown, which fits into a socketed end 37 of the worm which
projects through a rear false wall of the lower portion of the
lower housing section. The winch has a drum 38 on which a pair of
cables 41 and 42 are wound. The cable 41 is connected to a pair of
cables 43 and 44 which extend over pullies, severally 46, secured
to the rear end wall upper portion of the lower housing section and
are secured to the lower edges of the upper housing section side
walls. The cable 42 passes over a pulley 46.1 mounted on the front
wall of the lower portion of the lower housing section and is
connected to a pair of cables 47 and 48 which pass over pulleys,
severally 49, mounted on the upper portion of the front end wall of
the lower housing section adjacent the upper edge thereof and are
secured to the side walls near the lower edges thereof. The
arrangement so illustrated and described results in centering of
the upper housing section on the lower housing section during
movement so that special guides are not required and, further, as
the drive is through the worm type winch, the upper housing section
is automatically locked in its raised position but can be lowered
by reverse operation of the winch.
The left and right side walls 31 and 32 of the upper housing
section are provided with openings 53 and 54, respectively, which
are substantially the same length as the openings 25 and 26 and
which open out of the lower edge of said upper housing section side
walls but terminate short of the roof of the upper section so as to
provide upper side wall portions 55 and 56, respectively and, lower
side wall portions, severally 57.
Left and right drawers 61 and 62, respectively, are mounted in the
openings of the lower housing section for movement through the
openings in the lower and upper housing sections between retracted
positions, as shown in FIGS. 1 and 4, and expanded positions, as
shown in FIGS. 2 and 5. The drawers are disproportionate in width.
The right hand drawer 62 is designed to carry a bunk or bed and the
left hand drawer 61 is designed to carry kitchen equipment and the
like which, in total, are heavier than a bed and the like so that
the combined center of gravity of the drawers and equipment they
carry when the drawers are placed in the extended or retracted
conditions, is substantially centered over the center line of the
unit.
The left drawer 61 has a body portion, generally 63, which has
front and rear end walls 65--65, a bottom wall 66, a lower side
wall portion 67, and an upper side wall portion 68 which is inset
relative to the lower side wall portion 67. A roof section
generally 69 has a roof 71, end walls 72--72, and an outer side
wall 73, and telescopically fits over the upper portion of the
drawer 61 against the upper side wall portion 68 thereof for
movement between an elevated position, as shown in FIGS. 2 and 5,
and a lowered position, as shown in FIGS. 1 and 4. Dimensions of
the housing unit thus far described are so related that in the
contracted condition the roof section 69 of the drawer fits beneath
the upper housing section, inside the upper side wall portion 55
thereof, with said upper side wall portion and the lower side wall
portion 67 of the drawer flush with each other. In the expanded
condition, as shown in FIGS. 2 and 5, the upper housing section of
the unit is raised sufficiently to enable the raised roof section
of the drawer to clear the lower edge of the side wall at the
opening 53 to permit the drawer and roof section to be disposed in
the extended position.
The drawer 61 is supported at each end by support assemblies,
generally 75, which can be disposed, selectively, to provide
rolling support for the drawer so the latter can be moved easily
between its retracted and extended positions or to provide
frictional resistance to movement of the drawer so that the latter
is frictionally restrained from movement from either of said
positions.
A support assembly, shown partially in FIG. 2, outlined in FIGS. 4
and 5 and in detail in FIGS. 6 and 7, includes a U-section rail
which has an inboard portion 77, see FIG. 6, secured inside the
upper portion of the lower housing section, not shown in FIG. 6,
against an adjacent end wall, the outer end 78 of the said inboard
portion terminating short of the adjacent lower side wall portion
57 of the upper housing section when the latter is fully lowered.
An outboard rail portion 79 is hingeably connected at the outer end
of the inboard portion on a hinge bolt 81 for movement between a
stowed vertically upstanding position FIG. 4 and an extended
position, FIG. 2 and 5, in which it swings outwardly to a position
co-extensive with the inboard portion. As shown in FIGS. 6 and 7 an
elongated U-shaped brace piece 82 is mounted on the bolt 81 inside
the outboard rail portion and is welded thereto as at 83 for
swinging movement therewith. The brace piece it is seen provides
additional support for fore and aft alignment of the inboard and
outboard portions of the rail and prevents the outboard portion
from swinging downwards past the co-extensive position. In the
co-extensive position the inboard and outboard portions of the rail
present upper bearing surfaces which lie in a common plane. A cable
85, see FIG. 2, connected between the lower housing unit and other
end of the outboard portion of the rail provides additional support
for said portion.
The drawer is supported on the rail by an elongated box-sectioned
support member 91, FIG. 6, which is bolted to an outer surface of
an end wall of the drawer, immediately above the rail and has a
flat under wall 92 which rests on and frictionally engages the
upper surface of the rail.
An extendable and retractable roller assembly, generally 95, is
mounted in the support member operable, selectively, to provide
either frictional or rolling support of the drawer on the rail. The
roller assembly includes rollers, severally 96, which are mounted
on axles 97 carried on lower end of yokes severally 98. The yokes
are mounted for a pivotal movement, near their midlength, on pins
101 which extend transversely through the support member. The upper
ends of the yokes have pivotal connections severally 102 with a
push/pull rod 103 which extends longitudinally through the support
member. A lever 105 is mounted for pivotal movement on a pin 106 at
an outer end of the support member and also has a pivotal
connection at, 108, with the push/pull rod so that movement of the
lever effects longitudinal movement of the push/pull rod and swings
the roller yokes about the pins 101. The parts are so arranged that
with the lever in an upright position, as shown in solid outline,
the rollers take a retracted position as shown in solid outline.
When the lever is swung downwards to a position as shown in broken
outline the movement of the push/pull rod swings the rollers
through an over-center position in which they project through
openings severally 110, in the under wall 92 of the support member
so as to engage the rail and lift the support member off the
latter. Engagement of the lever with a stop 110.1 which can be a
pin extending through the support member limits rotation of the
yokes about their pivot pins 101 to the over center position so
that the rollers are effectively releaseably locked in extended
positions and can only be returned to retracted positions by
reverse operation of the lever. A coil spring 111 mounted on the
pivotal connection 108 bears against the push rod and lever and
normally urges the lever to an upward extending position so as to
maintain the rollers in the retracted positions.
Inner and outer spaced stops 112 and 112.1 are secured to the
support member for engaging a bracket 113 mounted on the adjacent
end wall, not shown in FIG. 6, of the lower housing section to
limit movement of the drawer between its extended and retracted
positions and to limit vertical movement of the drawer. A spring
connecting bracket 114 is also mounted on the inner end of the
support member. A similar rail, support member and roller assembly
provides support for the opposite end of the drawer.
Referring to FIGS. 4 and 5, the roof section 69 of the drawer 61 is
automatically raised to its extended position, when the upper
housing section is raised to its extended position, by a spring
operated hoist assembly, generally 115 located at each end of the
drawer. Each hoist assembly has a normally tensioned coil spring
115.1 which is connected at one end to the bracket 114 of the
adjacent support member 91 and is connected at its other end,
substantially at the midpoint of a lever 116 which is pivotally
mounted at one end 116.1 on a pivot pin 118 projecting from the
adjacent end wall 65 of the drawer 61. A pair of cables 119 and 121
are connected to the other end of the lever 116 and pass upwards
over pulleys, severally 121.1, mounted adjacent the upper edge of
the end wall 65 of the drawer 61 and are connected to the drawer
roof section adjacent the lower edge of end wall 72 thereof an
opposite sides of the center of gravity of the roof section 69. It
is seen that when the roof section is lowered the cables are drawn
over their respective pulleys thus rotating the lever 116 upwards
around its pivot pin 118 thus extending the spring and increasing
its tension. When the upper housing section 27 is raised the lever
swings downwards under the action of the spring thus lifting the
roof section of the drawer so that it follows the upper housing
section as the latter is raised.
In order to maintain a near even tension on the cables 119 and 121
as the roof section moves between its raised and lowered positions
the lever 116 is disposed so that as it rotates upwards as the roof
section of the drawer descends under the weight of the lowered
upper housing section 27, the angle between the lever axis and the
cables 119 and 121 increases from an acute angle to substantially a
right angle. Thus, as tension of the spring increases, lever
advantage of the spring on the cables decreases. Relationship of
spring extension and angular change is so determined that tension
on the cables throughout full movement of the roof section of the
drawer between its raised and lowered positions remains
substantially constant.
The roof section 69 is guided for vertical movement by a vertical
guide piece 122, FIGS. 2 and 5, secured to the front and rear
walls, 65 of the drawer and fits in a way, not shown, in the drawer
roof section. Upward movement of the drawer roof section is limited
by engagement of stops, severally 123, secured to lower edges near
the corners of the drawer roof section and upper edges near the
corners of the drawer body portion.
To effect sealing of the housing unit in either its expanded or
contracted condition, against wind and weather, novel sealing
arrangements are employed. FIG. 8 shows a typical sealing
arrangement for sealing an end wall 65 of a drawer and the forward
wall 23 of the lower housing section. The end wall of the drawer
has vertically disposesd laterally extending flange 125 positioned
near the inner edge of the drawer end wall which engages, when the
drawer is moved to its fully extended position, bristles of a brush
126 which extends vertically along the inside face of the wall 23
adjacent. A flexible flap 127 is secured to the end wall 23
outboard of the brush 126 against which the flange 125 bears when
the drawer is moved to the extended position. This combination
results in a virtually weatherproof seal.
As shown in FIG. 9 the brush 126 and flap 127 serve to provide a
seal between the end wall 23 and the outboard hinged portion 79 of
the rail 77 when the latter is swung to the stowed position.
As shown in FIG. 10 a brush seal arrangement is, effectively,
employed for effecting sealing engagement between the upper and
lower housing sections when the upper section is in its raised
position. As shown a brush 130 is secured inside the forward end
wall 33 of the upper housing section along and adjacent the lower
edge thereof and a brush 131 is secured to the adjacent end wall of
the lower housing section on the outer surface thereof extending
along the upper edge. The brushes 130 and 131 move into engagement
with each other when the upper housing section is fully raised. A
similar sealing arrangement, provides sealing engagement between
the adjacent rear walls of the upper and lower housing section and
between three sides of the drawer roof section 69 and the drawer
body portion 65.
Referring to FIGS. 4 and 5, sealing between the roof section 69 of
the drawer and the upper housing section 27 is provided by means of
an external flange 134 which extends outwards of the inner edges of
the drawer roof and end walls and which carries a resilient
non-wicking sealing element 135 which engages the inside surface of
the upper housing section adjacent the opening therein. Brush
seals, severally 136, are used to provide sealing engagement
between the drawer bottom and the side wall of the lower housing
section.
The right hand drawer 62 has a roof section 137 similar to the roof
section of the drawer 61 which is operated by a spring urged hoist
138 which operates in a manner as described with reference to the
spring urged hoist associated with the left hand drawer 61.
Furthermore sealing arrangements of the drawer 62 is similar to
that described with reference to the drawer 61.
The drawer 61 and likewise the drawer 62, see FIG. 2, are provided
with inspection and service panels severally 139 and the side walls
of the roof sections on each of the drawers have windows severally
141. Both end walls of the upper and lower housing sections are
provided with windows severally 142 and the rear wall of the lower
housing section has a door 143. The door, see FIG. 1, is partially
covered by the upper housing section when the unit is contracted
and the worm socket 37 of the winch is covered by the tailgate of
the truck so that with the tailgate locked unauthorized entrance
into the housing unit is effectively prohibited.
OPERATION
The housing unit, mentioned is disposed in a contracted position
for travelling so as to minimize wind resistance. To set up the
unit for habitation the end gate of the truck is lowered and the
upper section of the unit is raised by operation of the winch --
the roof sections of both drawers automatically move to the fully
extended position as the upper housing section is raised. The
hinged outboard portion of the rails at each end of the drawers are
then swung outward to their horizontal positions and the operating
levers of the roller assemblies are then operated to extend the
rollers. The drawers are then pulled out to their extended position
and the rollers then returned to their retracted position to lower
the supporting members of the drawers onto their respective rails.
The housing unit is thus ready for occupancy.
To return the unit to its contracted position the drawer rollers
are moved to their extended positions and the drawers moved inwards
to their retracted position and the rollers then returned to their
retracted positions so that the drawer is frictionally secured
against movement. The hinged outboard portions of the rails are
then swung upwards to their stowed positions against the outer end
of each of the drawer supporting members and the upper housing
section is lowered. The lower side portions of the side walls of
the upper housing section extend over the outboard hinged portions
of the rails so that said portions cannot again swing outwardly.
The drawers are, therefore, held captive in their retracted
positions.
ALTERNATE EMBODIMENT
FIGS. 11 and 12 show another embodiment 150 of a housing unit in
accordance with the invention which is shown in an expanded
condition in FIG. 12 and in a contracted position in FIG. 11.
The housing unit 150 has an upper housing section 151 and a lower
housing section 152 which are substantially similar to the upper
and lower sections of housing unit 10, the upper housing section
151 being raised and lowered by a cable and winch arrangement, not
shown, which is the same as that described with reference to the
unit 10.
Left and right drawers 153 and 154, are mounted in the lower
housing section 152 in the same manner as are the left and right
drawers of unit 10 for movement between retracted positions shown
in FIG. 11 and extended positions as shown in FIG. 12. Support
assemblies, generally 156, which are the same as the support
assemblies 75 of unit 10 are employed to facilitate movement of the
drawers 153 and 154 between extended and retracted positions.
Left and right side walls 157 and 158, of the upper housing section
151 do not have openings in the same manner as the left and right
side walls as described with reference to the upper housing section
of unit 10 but extend unbroken from top to bottom.
The drawers 153 and 154 have fixed roofs 161 and 162, respectively,
which, when the upper housing section 151 is fully raised, the roof
just clears the lower edges of the side walls so that the drawers
can be moved between extended and retracted positions. Inner edges
of the roof sections 161 and 162 are provided with upstanding
flanges 163 and 164 which make sealing engagement with the side
walls when the drawers are fully extended. Sealing arrangements as
described with reference to the unit 10 are employed in the unit
150 where required.
The unit 150, it is seen, when contracted provides minimal frontal
and side area yet when expanded provides head room beneath the
upper housing section which is substantially the same as that
provided by the unit 10. Head room beneath the roofs of the drawers
is however somewhat reduced -- substantially by the extent of
vertical movement of the roof sections of the drawers of unit
10.
Manufacturing costs, however, of the unit 150 are correspondingly
less than the costs of the unit 10 as the fixed roof section
obviates the necessity of providing a hoist assembly and
consequently eliminate much of the sealing arrangements found in
the unit 10. The weight of the unit 150 is correspondingly less
than the weight of unit 10 and is more adaptable to smaller
conveying units.
* * * * *