United States Patent (19) (11) 4,133,571

Filios 45 Jan. 9, 1979

(54) EXPANDABLE CAMPER BODY FOREIGN PATENT DOCUMENTS
Inventor: Frank T. Fillios, 53 Hillside Ter, 2026360 12/1971 Fed. Rep. of Germany ........ 296/23 C
(76. Belmont, Mass, 02178 237899 12/1943 Switzerland ............................... 296/26
Primary Examiner-Joseph F. Peters, Jr.
21) Appl. No.: 766,832 Assistant Examiner-John A. Carroll
Attorney, Agent, or Firm-James J. Cannon, Jr.
22) Filed: Feb. 7, 1977 57 ABSTRACT
An expandable camper body having an aft section
51 Int. Cl’................................................ B60P3/32 which telescopes within a forward section, folding sup
(52) U.S. C. ...................................... 296/23 C;52/67; port tracks for guiding and supporting the aft section
296/26 when extended, said support tracks providing an exten
(58) Field of Search ......................... 296/23 C, 26, 27; sion of tracks within the forward section, hydraulic
52/67; 135/1 R, 1 A power for raising and lowering said support tracks and
powered gear drive to extend and retract said aft sec
56 References Cited tion on said tracks. Flexible utility connections are pro
vided such that all utilities are operative in the extended
U.S. PATENT DOCUMENTS or retracted positions.
3,181,910 5/1965 Thomas......... 52/67
3,212,810 10/1965 Bass ........... ... 296/23 C 3 Claims, 11 Drawing Figures
U.S. Patent Jan. 9, 1979 Sheet 1 of 3 4,133,571
 U.S . Patent Jan. 9, 1979 Sheet 2 of 3 4,133,571

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U.S. Patent Jan. 9, 1979 Sheet 3 of 3 4,133,571
 4,133,571 2
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outwardly, some mechanical systems must be dupli
EXPANDABLE CAMPER BODY cated. If one side expands only, problems of tracking
BACKGROUND OF THE INVENTION
and weight and balance arise. Hence, the present inven
tion is designed for horizontal expansion along the lon
1. Field of the Invention gitudinal axis of the camper body. This embodiment
This invention pertains to expandable camper bodies, lends itself to simple mechanical systems and minimal
and in particular to a camper body composed of for operational problems.
ward and aft sections, the aft section capable of a tele This invention relates to camper bodies, and is di
scoping movement within the forward section and the rected particularly to a camper body which, when ex
support tracks for the aft section capable of being raised 10 panded, approximately doubles in size. The principal
and folded hydraulically for ease of transport. object of this invention is to provide a camper body
2. Description of the Prior Art which, when retracted, is relatively small and easy to
The prior patent art is replete with examples of ex transport and can be compacted to approximately one
pandable camper bodies and house trailers. However, to . half its extended volume to provide the least visual
the best of the inventor's knowledge, none of the prior 15 obstruction and wind resistance in transport from place
art devices has been a commercial success. An analysis to place.
of the prior art indicates that the basic problems relate A more particular object of the invention is to pro
to the cost effectiveness of the prior art designs. Most vide a camper body which comprises a telescoping aft
are too expensive to manufacture, too difficult to oper section so arranged as to permit simplified, inexpensive
ate and provide too little additional space relative to the 20 construction and ease of expansion when parked.
additional costs. For example, in U.S. Pat. No. Another object is to provide improved and simplified
3,212,810, a collapsible house trailer is described which track means interconnecting the forward and aft sec
collapses both vertically and horizontally. The provi tions of the camper body for relatively simple horizon
sion of vertical expansion adds a little to the value of the tal movement in expanding and retracting the camper
trailer, but a substantial amount to the cost of produc 25 body such that the expansion and retraction may be
tion. The longitudinal expansion of this trailer results in performed by one person in a short period of time.
a separation of its front and rear wheels, which bear the Another object of the invention is to provide an ex
load of its weight. To offset the change in weight and pandable camper body which automatically secures the
balance distribution, a strong expandable undercarriage forward and aft sections in tight interfitting engagement
or structural frame must be provided, though details are 30 at the fully extended and fully retracted positions for
not shown. Furthermore, the provision of vertical and structural integrity.
horizontal expansion creates, in the fully collapsed state, Another object of this invention is to provide a novel
a situation in which three walls overlap on portions of means for guiding the movable aft section of the camper
each side of the trailer, thereby costing a substantial loss body and a power driven means for effecting such
of useful space relative to the gross space. U.S. Pat. 35 movement, so that virtually no manual labor is required
Nos. 2,902,312 and 2,732,251 each teach horizontally, to expand or retract that section, and so that the expan
latitudinally, expandable house trailers. The first patent sion and retraction may be effected with minimum ef
requires jacks under both fixed and movable sections for fort and a few minutes time.
support, and requires a complicated folding floor mech Another object of this invention is to provide an
anism. The second also has a folding floor which inter 40 improved hydraulic fluid pressure system for operating
feres with use of the trailer in the collapsed position. the expansion and retraction of the aft section of an
Furthermore, U.S. Pat. No. 2,732,251 requires an exten expandable camper body.
sive and intricate hydraulic system for its operation. It is SUMMARY OF THE INVENTION
clear that the trailer of this invention is too expensive to
be practical. Among the recent patent art, U.S. Pat. No. 45 The present invention relates to an expandable
3,740,088 illustrates telescopic end sections for a trailer. camper body which may be mounted on the chassis of
This is a typical example of a non-cost-effective design, a truck, preferably a delivery type van. The expandable
in that the additional bunk space provided does not camper body includes a forward, fixed section mounted
justify the additional cost of fabrication, U.S. Pat. No. on the truck chassis, and an aft section which snugly
3,915,492 teaches a trailer that is expandable horizon 50 telescopes within the forward section in the retracted
tally either along its latitudinal axis or along its longitu position and telescopes rearwardly along the longitudi
dinal axis. The embodiments taught in this patent are nal axis in the expanded position. Each section con
mechanically complex and somewhat incomplete. It is prises a floor, three side walls, and a roof, there being no
unclear how the roof extends to cover the extended common side wall between the two sections. Since the
areas, how the utility lines are handled and how the 55 aft section fits completely within the forward section
extended areas are supported. Furthermore, a consider and extends all the way to its front wall, expansion of
able amount of weight is added to the trailer and consid the aft section substantially doubles the interior of the
erable internal height is lost with its double flooring camper body. For mechanical simplicity and structural
arrangement. integrity, the expanded aft section is supported by a pair
The expandable camper body of the present inven of hydraulically operated, folding support tracks. When
tion is specifically designed to overcome the limitations the aft section is fully telescoped within the forward
of prior art designs by providing mechanical simplicity section, these support tracks are fully folded and stored
with sturctural integrity in an inexpensive, cost-effec vertically against the rear wall of the aft section. When
tive embodiment. The present invention does not utilize the aft section is to be expanded rearward, these support
vertical expansion because the additional structural 65 tracks are unfolded hydraulically and lowered to a hori
requirements are not worth the minimal additional use zontal position such that they are aligned longitudinally
ful space. Horizontal expansion along the latitudinal with corresponding tracks in the floor of the forward
axis presents its own problems. If both sides expand section. As the support tracks are lowered, two pairs of
 3 4,133,571 4.
spaced apart legs are unfolded downwardly to provide FIG. 11 is a floor plan of the camper body of FIG. 2
vertical support for the tracks, one supporting each with the aft section extended.
section of track. These support tracks in effect are ex DESCRIPTION OF THE PREFERRED
tensions of the truck chassis frame and serve the dual
EMBODIMENT
purpose of guiding the aft section as it moves rearward
and supporting it during and after its extension, thus Referring now to the drawings, FIG. 1 is a side per
eliminating the need for auxiliary jacks. The aft section spective view of a delivery van 10 having mounted
is able to move inwardly and outwardly by means of thereon the expandable camper body 12 of the present
small wheels mounted on the underside of its floor invention in its fully retracted position, and FIG. 2 is a
which ride along the support tracks and corresponding 10 similar view with expandable camper body 12 fully
tracks in the floor of the forward section. These tracks extended. Expandable camper body 12 comprises a
are spaced toward either side wall substantially above forward section 14 mounted on the chassis of van 10 and
and parallel to the chassis frame. When the aft section is an aft section 16 which is capable of retraction within
expanded rearward, covers are placed over the tracks 15 forward section 14 and extension outward therefrom.
of the forward section to provide a level floor in the Forward section 14 has a floor 18, sidewalls 20, front
forward section. The means for effecting movement of wall 22 and roof 24. Aft section 16 has a floor 26, side
the aft section inwardly and outwardly is provided by a walls 28, rear wall 30 and a roof 32. FIGS. 1, 2 and 3
centrally disposed, longitudinally oriented gear rack in illustrate the relative positions of these walls, floors and
the underside of the aft section. A corresponding open 20 roofs. Allowing for the fact that aft section 16 can be
track in the floor of the forward section receives this fully telescoped within forward section 14, aft section
gear rack as the aft section is telescoped within the 16 has slightly smaller dimensions than forward section
forward section. A motor driven spur gear mounted at 14. When aft section 16 is fully extended, the floor space
the rear end of the truck chassis and just under the floor and volume of camper body 12 are nearly doubled.
Both sidewall 20 of forward section 14 and sidewall 28
of the forward section meshes with this gear rack to 25 of aft section 16 have at least one door 34, 38 respec
effect the forward and rearward movement of the aft
section. When the aft section is fully extended, a cover tively and at least one window 36, 40 respectively.
is placed over the centrally disposed receiving track to Doors 34, 38 and windows 36, 40 are so positioned that
provide a level floor in the forward section. When not they coincide when aft section 16 is fully retracted
within forward section 14. Both aft section 16 and for
in use these covers are stored in the floor in the aft 30
section. Utility lines for gas, water and electricity run ward section 14 are so constructed that camper body 12
along the base of the sidewalls, of the forward and aft is usable whether in a fully retracted position or a fully
extended position.
sections. Quick release connections are provided be Aft section 16 is guided to and supported in its fully
tween the forward and aft section lines such that when extended position by support tracks 42, the details of
the aft section is retracted, its utility lines may be con 35 which are illustrated in FIGS. 4 through 9. FIG. 4
nected to the front end of the forward section and when illustrates the support tracks 42 fully folded and secured
the aft section is extended, its utility lines are connected in a storage and travel position on the exterior rear wall
to the rear end of the forward section. Whether the aft 30 of aft section 16 which is fully retracted within for
section is extended or retracted, the camper body is able ward section 14. FIG. 5 illustrates support tracks 42 in
to be used for living purposes. All controls for operat 40 a fully extended horizontal position. In order to be
ing the extension and retraction of the aft section are folded, support tracks 42 are divided into two hinged
mounted on the rear of the camper body so that the sections, as will be described hereinafter in reference to
operator may view its operation, a distinct safety fea FIG. 9. Support tracks 42 are hinged to van chassis 10
ture. and, in effect, form an extension of the chassis frame to
BRIEF DESCRIPTION OF THE DRAWINGS 45 support the weight of aft section 16 when extended.
Each support track 42 includes a pair of spaced legs 44,
FIG. 1 is a side perspective view of the camper body 46, one under each half of support track 42. Legs 4, 46
of the present invention mounted on a van chassis, with fold downward to a vertical position, as described here
the aft section retracted within the forward section. inafter in reference to FIG. 9, and are adjustable to
FIG. 2 is a side perspective view of the camper body 50 compensate for variations in ground level in order to
of FIG. 1 with the aft section fully extended. maintain support tracks 42 in a level, horizontal posi
FIG. 3 is a sectional view of the camper body taken tion. A pair of brace rods 48 are placed between support
along the line 3-3 of FIG. 2. tracks 42 to maintain proper longitudinal alignment
FIG. 4 is a rear view with the support tracks fully with van chassis 10.
folded. 55 Referring now to FIG. 5, support tracks 42 also pro
FIG. 5 is a partially cut-away rear view with the vide guide means for supporting aft section 16 for in and
support tracks fully extended and in position to receive out telescoping motion with respect to forward section
the aft section. 14. To this end, support tracks 42 have longitudinally
FIG. 6 is a cut-away view of the rear of the forward extending rectangular recesses forming depressed
section showing the track system of the forward sec 60 tracks 50 and the floor 18 of forward section 14 has
tion. longitudinally extending rectangular recesses forming
FIG. 7 is a view of the gear rack on the underside of depressed tracks 52, spaced substantially along the lines
the aft section meshed with the driving spur gear. of the chassis frame of van 10 and aligned with tracks
FIG. 8 is a detail view of an aft section wheel. 50. The underside of aft section 16 (FIG. 10) has similar
FIG. 9 is a detailed view of the support track hydrau 65 but complementary track members 53 in register with
lic system. and complemental to the recesses of forward section 14.
FIG. 10 is a cut-away view of the underside of the aft A plurality of wheels 62 are journaled in spaced relation
section of the camper body. within and along upper recesses 53, which wheels sit in
 4,133,571 6
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depressed tracks 50, 52, thereby providing vertical sup relation the insides of side walls 20 of the forward sec
port for aft section 16 when retracted and at the same tion 20. All shoulders, horizontal and vertical are fitted
time permitting smooth in and out or telescoping move with resilient seals (not illustrated) which abut similar
ment of aft section 16 relative to forward section 14. seals on the shoulders of the corresponding forward
The actual propulsion means comprises a motor 54 5 section members to provide weatherproofing in ex
driving a spur gear 56, both mounted at the rear of van tended or retracted positions. A scraper is also provided
chassis 10 (FIGS. 5 and 6), the spur gear 56 engaging a to clean the underside of aft section 16 while being
gear rack 58 centrally located along the longitudinal retracted. The seals and scrapers also do not form part
axis of the underside of aft section 16 (FIGS. 6, 7 and of the invention and will not be described further.
10). A corresponding receiving track 60 is located in the 10 FIG. 11 is a floor plan of the expandable camper body
floor 18 of forward section 14 to receive gear rack 58. 12 of this invention. This plan shows all kitchen areas
Motor 54 may be driven by the battery of van 10 or by such as sink 78, stove 76 and cabinets 80 located in aft
an external power source. When aft section 16 is fully section 16. A shower and toilet (not shown) are located
extended, covers (not shown) are placed over tracks 52, in forward section 14. All gas, electric and water utility
60 to provide a flush floor 18 in forward section 14. 15
lines 86, 87 are enclosed in sidewall 28 of aft section 16,
When aft section 16 is to be retracted, the covers are and sidewall 20 of forward section 14. When aft section
stored in floor 26 of aft section 16. 16 is fully extended, quick release connections (not
FIG. 5 also illustrates double acting hydraulic cylin shown) connect utility lines 86 at the front end of side
ders 72, 73 and 74, described in reference to FIG. 9. wall 26 to utility lines 87 at the rear end of forward
FIG. 6 is a sectional view of the rear of forward 20 sections 14. When aft section 16 is retracted, these quick
section 14 showing aft section 16 fully retracted, the release connections are disconnected and reconnected
wheels 62 of aft section 16 in depressed tracks 52, spur to the prime utility sources of van 10.
gear 56 and its motor 54. FIG. 10 is a partially cut-away view of the floor 26 of
FIG. 7 is a cut-away view illustrating the engagement aft section 16 showing the relative position of wheels 62
of spur gear 56 with gear rack 58. 25
and gear rack 58.
FIG. 8 is a cut-away view showing a wheel 62 in a In summary, expandable camper body 12 is designed
depressed track 50, 52, for movement of aft section 16. to overcome many problems encountered in prior art
FIGS. 5 and 9 illustrate the simple hydraulic system expandable designs. The utilization of folding support
which serves to extend and retract support tracks 42 tracks provides mechanical simplicity and structural
and their vertical legs 44, 46. This system, actuated by 30 rigidity in a very cost-effective embodiment. The sim
controls (not shown) located on rear wall 30 of aft plified gear rack and spur gear provide a simple, effi
section 16, causes support tracks 42 to extend and re cient and safe means for extension and retraction of the
tract with a minimal number of double acting hydraulic aft section of the camper body. The design of the pre
cylinders. In normal travel position, support tracks 42 ferred embodiment enables the camper body to be uti
are stored as shown in FIG. 4. In the normal lowered 35 lized whether extended or retracted. It should be noted
position, support tracks are extended as shown in FIG. that the principles of the present invention could also be
5. Each track 42 is constructed in two hinged sections, utilized for an expandable camper body or house trailer
66, 68. which expands horizontally along the latitudinal axis of
Hydraulic means are provided for folding and unfold the camperor trailer. However, in such an embodiment,
ing support tracks 42, as well as for raising and lowering additional support tracks and perhaps an additional
their legs 44, 46. To this end a pair of double acting motorized spur gear and gear rack might be required. In
hydraulic cylinders 73 are fitted longitudinally under
forward section 14, the actuating piston thereof being any event, the cost effectiveness of such an embodiment
connected in any suitable manner to the van chassis 10. would be unfavorable compared with the preferred
To permit the lowering and unfolding of track support 45 embodiment described and illustrated herein. In con
42 from the raised position of FIG. 4, dual acting hy trast to the prior art, the present invention in its pre
draulic cylinder 73 mounted on the rear of van chassis ferred embodiment is designed to maintain favorable
10 pushes track section 66 away from rear wall 30. At weight and balance moments for the aft section when
the same time a second dual acting hydraulic cylinder expanded.
72 vertically installed at the base of opening 75 in leg 44 50 While the preferred embodiment has been discussed
pushes ends of slidably mounted diagonal brace mem in detail, various modes of carrying out the invention .
bers 77, 79 also folded into opening 75 upwards. The are contemplated as being within the scope of the fol
other ends of braces 77, 79 are pivotally secured to track lowing claims, particularly pointing out and distinctly
sections 66, 68. As braces 77, 79 are pushed upward, claiming the subject matter which is regarded as the
hinged track sections 66, 68 are pushed apart to unfold. 55 invention.
I claim:
r
Also at the same time a third hydraulic cylinder 74
unfolds rear leg 46. The process of raising and folding 1. An expandable camper body for mounting on a
support tracks 42 and legs 44, 46 is the reverse of the truck chassis comprising:
process just described. The hydraulic cylinders are a forward fixed section including a roof, two spaced
duplicated for each support track 42. Flexible hydraulic 60 parallel side walls, a floor and a front wall, said
lines (not shown) lead to the usual hydraulic pump and forward section being mounted on a truck chassis;
control system, which forms no part of the invention an aft section including a roof, two spaced parallel
and therefore is not further described herein. Limit side walls, a floor and a rear wall, said aft section
switches (not illustrated) can be used to automatically being movable in and out with respect to said for
stop the relative movement of the aft section 16 relative 65 ward section in telescoping fashion;
to the forward section 14. a support and guide mechanism to guide and support
It should be understood also that the side walls 28 of said aft section as it is extended from and retracted
the aft section 16 are offset so as to bypass in spaced into said forward section;
 4,133,571
7
said guide and support mechanism further compris two equal sections, the front end of said first section
ing: being hinged to the chassis of said van so that it
a pair of spaced apart, parallel longitudinal rectan may bold upwards against the rear wall of said aft
gular depressions forming tracks recessed in the section it its retracted position;
floor of said forward section; 5 said two sections being hinged together at the middle
a pair of spaced apart support and guide tracks of said support track such that said second section
extending rearward from said van chassis, each folds downward against said first section when said
of said support tracks having a longitudinal rect first section is raised;
angular depression forming a longitudinal exten a first vertical support leg positioned under said mid
sion of said tracks in said forward section; O dle hinge and having two diagonal braces one ex
at least two vertical adjustable legs for each of said tending to each of said sections;
support and guide tracks; said first vertical support leg pivotally mounted such
horizontal support braces positioned between said that it can fold under said first section, and having
support and guide tracks to maintain proper 15 an opening therein such that said diagonal braces
track alignment; may be folded thereinto;
a plurality of wheels mounted on the underside of a second vertical leg pivotally mounted to rear of said
second section such that it can fold under said
said aft section to ride in said recessed tracks in second section.
said forward section and in said support and 3. The expandable camper body of claim 2 further
guide tracks; 20 including:
drive means to move said aft section along said a first dual action hydraulic cylinder to raise and
depressed tracks to extend and retract said aft lower said said first support track section mounted
section; at the rear of said van chassis;
said drive means further comprising: a second dual action hydraulic cylinder to fold and
a gear rack mounted on the underside of said aft 25 unfold said
section; first and second support track sections, by raising and
a spur gear mounted at the rear of said van chassis positioning said diagonal braced, mounted at the
which engages said gear rack; base of said first vertical leg;
an electrical motor to drive said spur gear. a third dual action hydraulic cylinder to raise and
2. The expandable camper body of claim 1 wherein 30 lower said second vertical leg.
each of said support and guide tracks further comprises:

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