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39-518: In contrast to most motorhomes which were manufactured on drivetrain-equipped frames supplied by a chassis manufacturer; GMC designed, engineered, and built the entire vehicle, and in most cases the interiors, completely in-house. Empty shells were also supplied to other RV manufacturers for interior outfitting and to specialty manufacturers for custom outfitting, ranging from mail delivery and mobile training facilities to people movers and ambulances. Industry rumors had been circulating for some time that GM

78-533: A servomechanism that takes over the car's throttle to maintain a steady speed set by the driver. Speed control existed in early automobiles such as the Wilson-Pilcher in the early 1900s. They had a lever on the steering column that could be used to set the speed to be maintained by the engine. In 1908, the Peerless included a governor to keep the speed of the engine through an extra throttle lever on

117-429: A 40 US gallons (150 L) freshwater tank and a 40 US gallons (150 L) holding tank. Body construction consisted of a rigid frame made of welded aluminum extrusions. The body frame was mounted on the chassis steel ladder frame using body isolators. The floor was marine plywood, except where it sloped up at the extremities, where they were plate aluminum. The body panels are fiber-reinforced plastic (fiberglass) below

156-414: A GM vice president said today. Robert W. Truxell, general manager of GMC Truck & Coach said, “As a result of this action, GMC will be able to utilize production facilities more effectively for servicing growing truck demands.” Another factor is that the driveline for the new 1979 E platform which was in the process of being downsized (and on which Buick would debut its first-ever front-wheel-drive Riviera)

195-403: A U.S. patent for a "vacuum powered throttle control with electrically controlled air valve" in 1951, which was granted in 1956. Despite these patents, Riley, Exline, and subsequent patent holders were not able to collect royalties for any cruise control inventions. The first car with Teetor's "speedostat" system was the 1958 Chrysler Imperial (called "auto-pilot"), using a speed control dial on

234-488: A general term meaning improved cruise control. Dynamic set speed systems use the GPS position of speed limit signs from a database. Many systems also incorporate cameras, lasers, and millimeter-wave radar equipment to determine how close a vehicle is to others or other objects on the roadway. The technologies can be set to maintain a distance from vehicles in front of the car; the system will automatically slow down based on

273-405: A memory feature to resume the set speed after braking and a coast feature to reduce the set speed without braking. When the cruise control is engaged, the throttle can still accelerate the car, but once the pedal is released, it will slow down the vehicle until it reaches the previously set speed. On the latest vehicles fitted with electronic throttle control , cruise control can be integrated into

312-399: A product. Clay modeling was soon adopted throughout the industry and remains in use today. This automobile -related article is a stub . You can help Misplaced Pages by expanding it . Cruise control Cruise control (also known as speed control , cruise command , autocruise , or tempomat ) is a system that automatically controls the speed of an automobile . The system is

351-481: A silver-blue film of DI-NOC , replicating the painted surface of a vehicle. Upon completion of the full-scale clay, plaster cast segments were made of it. Dimensional drawings were made of this final design for tooling and early fiberglass prototype parts for the first prototype bodies. The motorhome had a front-wheel-drive transaxle, which GM called the Unitized Power Package , originally used in

390-418: Is described in two patents filed that year (US patents 3570622 and 3511329), with the second introducing digital memory , and was the first electronic device that controlled a car. Due to the 1973 oil crisis and rising fuel prices, the device became more popular in the U.S. "Cruise control can save gas by avoiding surges that expel fuel" while driving at steady speeds. In 1974, AMC, GM, and Chrysler priced

429-629: The Oldsmobile Toronado and Cadillac Eldorado with an Oldsmobile 455 cu in (7.5 L) V8 from the Toronado. In mid-1977 the engine was downsized to a 403 cu in (6.6 L) V8. (At the time, the Buick Riviera , which shared most of the same components, and used the same E-body platform, as the Toronado and Eldorado until its 1977 downsizing, was still using the conventional rear-wheel-drive layout.) Both used

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468-426: The 26-foot (7.9 m) coach. All GMC Motorhomes are 96 inches (240 cm) wide and about 9 feet (2.7 m) tall including the usually-installed roof air conditioner. Interior head room is 76 inches (190 cm). Gross vehicle weight rating for the 23-foot (7.0 m) coach was 10,500 pounds (4,800 kg) and 12,500 pounds (5,700 kg) for the 26-foot (7.9 m) coach. Most GMCs with factory interiors have

507-537: The GM-designated Turbo-Hydramatic 425 automatic transmission, with a wide roller chain drive to connect the output of the longitudinally-oriented engine to the transmission. The final drive was connected directly to the transmission, and power was fed to the front wheels using half-shafts, one of which ran under the front portion of the engine. The engine was fueled with regular gasoline stored in two 25-US-gallon (95 L) tanks. The GMC

546-636: The GMC configuration. These included the Cortez Motor Home from the Clark Equipment Corporation which initially offered a four-speed manual transmission with front-wheel drive, available from 1963 to 1970 until the division was sold to Kent Industries. From 1972 to 1977, a redesigned Cortez-SD was manufactured, initially by Kent and later a group of investors, using the same Oldsmobile 455 and three-speed automatic transmission that

585-620: The GMC motorhome adopted in 1973. Another parallel design was the Revcon motor home, which, starting in 1971, was an all-aluminum body front-wheel drive coach, initially with the same Toronado drive train as the later GMC. Beginning in 1978, the Revcon took on a more aerodynamic design similar to the just-canceled GMC Motor home, which included a slant nose and dual rear axle, while adopting a Chevrolet 454 engine and Turbo-Hydramatic 475 transmission. These were in production through 1990, with one coach built in 1991 using remaining components before

624-495: The United States during World War II to reduce gasoline use and tire wear. A mechanism controlled by the driver provided resistance to further pressure on the accelerator pedal when the vehicle reached the desired speed. Teetor's idea of a dashboard speed selector with a mechanism connected to the driveshaft and a device able to push against the gas pedal was patented in 1950. He added a speed lock capability that maintained

663-548: The car's speed until the driver tapped the brake pedal or turned off the system. A 1955 U.S. patent for a "constant speed regulator" was filed in 1950 by M-Sgt Frank J. Riley. He conceived the device while driving on the Pennsylvania Turnpike and installed his invention in his car in 1948. Another inventor named Harold Exline, working independently of Riley, also invented a type of cruise control that he first installed on his car and friends' cars. Exline filed

702-514: The cruise control. The "resume" feature has to be used each time after selecting the new gear and releasing the clutch. Therefore, cruise control is most beneficial at motorway /highway speeds when top gear is used virtually all the time. The speed limiter function, however, does not have this problem. Some advantages of cruise control include: However, when misused, cruise control can lead to accidents due to several factors, such as: Some modern vehicles have adaptive cruise control (ACC) systems,

741-433: The dashboard. This system calculated ground speed from the rotating speedometer cable and used a bi-directional screw-drive electric motor to vary the throttle position as needed. Cadillac soon renamed and marketed the device as "cruise control." In 1965, American Motors Corporation (AMC) introduced a low-priced automatic speed control for its large-sized cars with automatic transmissions. The AMC "cruise command" unit

780-429: The desired speed by pulling the throttle cable with a solenoid , a vacuum -driven servomechanism , or by using the electronic systems built into the vehicle (fully electronic) if it uses a 'drive-by-wire' system. All cruise control systems must have the capability to be turned off explicitly and automatically when the driver depresses the brake pedal and often also the clutch. Cruise control systems frequently include

819-450: The engine's speed to different loads (e.g., when going up a hill). Modern cruise control (also known as a speedostat or tempomat) was invented in 1948 by the blind inventor and mechanical engineer Ralph Teetor . He came up with the idea due to being frustrated by his driver's habit of speeding up and slowing down as he talked. A more significant factor in developing cruise control was the 35 mph (56 km/h) speed limit imposed in

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858-664: The factory closed. Clay model Clay modeling (or clay model making) for automobile prototypes was first introduced in the 1930s by automobile designer Harley Earl , head of the General Motors styling studio (known initially as the Art and Color Section, and later as the Design and Styling Department). Industrial plasticine , or "clay", which is used for this purpose, is a malleable material that can be easily shaped, thus enabling designers to create models to visualize

897-432: The final form. Once these models were completed, evaluated, and approved, full-sized drawings were made using 1/4 inch tape to outline the front, rear and side design. These drawings would guide the designers in the next stage: a full-size clay model. The clay full scale 26-foot (7.9 m) motorhome was created. Once the shape was completed, the clay surface was "polished" with a sponge and cold water and finished with

936-412: The front of the vehicle. A single door amidships on the passenger side provided access to the main passenger compartment. At the back of the vehicle, the entire rear body panel could be removed by loosening the bolts around its edges. This allowed beds, appliances, and other bulky items to be installed or removed. A total of 12,921 GMC Motorhomes were produced from model years 1973 to 1978. The interior of

975-625: The motorhome was constructed at the Gemini Corporation plant in Mt. Clemens, Michigan in 1973 and 1974 before being brought in house at GM for the remainder of production. Peter R. Fink, the owner of Travco motor homes, was the CEO of Gemini. The Gemini operation featured a progressive team concept with teams of workers constructing rooms of the motor homes in full, rather than performing repetitive tasks on an assembly line. Beginning operation in 1972,

1014-615: The option at $ 60 to $ 70, while Ford charged $ 103. In the late 1980s, an integrated circuit for Wisner's design for electronic cruise control was finally commercially developed by Motorola as the MC14460 Automotive Speed Control Processor in CMOS . The advantage of electronic speed control over its mechanical predecessor was that it could be integrated with electronic accident avoidance and engine management systems . The driver must manually bring

1053-627: The plant featured state-of-the-art equipment including one of the first programmable routers. Gemini closed a few years after General Motors discontinued production of its motor homes. Over 8,000 are currently listed in an international registry. Estimates suggest that 3,000 to 4,000 of the original production may still be in running condition. A press release datelined Pontiac, November 11, 1977, read as follows: “GMC Truck & Coach Division of General Motors plans to discontinue producing luxury MotorHomes and similar TransMode multi-purpose vehicles and convert those plant facilities to expand truck operations,

1092-419: The sides of the low-profile frame. With the exception of the wheel wells, the rear suspension does not intrude into the living space. The rear bogies are suspended using a double-ended reversible sleeve airbag that is pressurized by an automatic leveling system to maintain the designed ride height. The leveling system can also be manually controlled to level the coach at a campsite. The overall chassis design, from

1131-411: The steering wheel. Peerless successfully used a flyball governor. They advertised their system as being able to "maintain speed whether uphill or down." A governor was used by James Watt and Matthew Boulton in 1788 to control steam engines , but the use of governors dates at least back to the 17th century. On an engine, the governor uses centrifugal force to adjust the throttle position to adapt

1170-460: The use of an existing GM E platform powertrain and a modified rear suspension, has been considered an early ancestor of the crossover. The motorhomes were built in either 23-foot (7.0 m) or 26-foot (7.9 m) length, with about 90% of the total production being the latter. The wheelbase from the front wheels to the centerline of the rear tandem pairs is 140 inches (360 cm) for the 23-foot (7.0 m) coach and 160 inches (410 cm) for

1209-402: The vehicle from increasing engine speed to accelerate beyond the chosen speed. However, they will not apply the brakes in the event of overspeeding downhill, nor stop the car from going faster than the selected speed even with the engine just idling . Cruise control is less flexible on vehicles with a manual transmission because depressing the clutch pedal and shifting gears usually disengages

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1248-457: The vehicle up to speed and use a button to set the cruise control to the current speed. The cruise control takes its speed signal from a rotating driveshaft , speedometer cable, wheel speed sensor from the engine's RPM , or internal speed pulses produced electronically by the vehicle. Most systems do not allow the use of the cruise control below a certain speed - typically around 25 or 30 mph (40 or 48 km/h). The vehicle will maintain

1287-444: The vehicle's engine management system . Modern "adaptive" systems include the ability to automatically reduce speed when the distance to a car in front, or the speed limit, decreases. The cruise control systems of some vehicles incorporate a "speed limiter" function, which will not allow the vehicle to accelerate beyond a preset maximum; this can usually be overridden by fully depressing the accelerator pedal. Most systems will prevent

1326-509: The vehicles in front or continue to keep the set speed. Some systems cannot detect completely stationary cars or pedestrians, so the driver must always pay attention. Automatic braking systems use either a single or a combination of sensors (radar, lidar, and camera) to allow the vehicle to keep pace with the car it is following, slow when closing in on the vehicle in front, and accelerate to the preset speed when traffic allows. Some systems also feature forward collision warning systems, which warn

1365-780: The waistline frame extrusion and at the ends. The upper side body and roof panels between the ends are sheet aluminum. All of the body panels are bonded to the frame using adhesive. GMCs are notable for their large expanse of windows, which redefined the RV industry at the time. They often had luxury features common on upper models of GM brands, such as cruise control , air conditioning , AM / FM / 8-track sound systems, an aluminum/fiberglass body, as well as air suspension. Rear lower compartments provide space for generators and propane tanks. GMCs were optionally supplied with generators from Onan in 4,000 Watts and 6,000 Watts, many of which are still in service. There were no driver's or passenger's doors at

1404-604: Was actuated through a push-button on the dashboard once the car's desired speed was reached. The throttle position was automatically adjusted by a vacuum control that opened and closed the throttle based on input from the speedometer cable rather than through an adjustable control on the dashboard. The unit would shut off anytime the brakes were applied. Daniel Aaron Wisner invented an "automotive electronic cruise control" in 1968 as an engineer for RCA 's Industrial and Automation Systems Division in Plymouth, Michigan . His invention

1443-465: Was equipped with front disc brakes and drums on all four rear wheels. The front-drive configuration eliminated the driveshaft and rear differential and the solid axle found on most front-engined motorhomes. As a result, the floor could be built with about 14 inches (36 cm) clearance above the roadway. The floor was too low for a rear cross axle, and GM designed the rear suspension as a tandem pair of wheels, mounted on bogies that rode on pins attached to

1482-598: Was going to build a motorhome. On February 7, 1972, it was made official. About this time the new vehicle was known as the TVS-4, Travel Vehicle Streamlined. The motorhome design continued to evolve in the two main areas of styling and chassis. The Design Center was continuing with both the external and interior designs. There were twelve designers working with sketches and 1/8 scale (A-scale) clay models . Three or four of these 1/8 scale clay models were made, each with unique design characteristics, each refining their shapes closer to

1521-614: Was lighter duty and incompatible with the GVW of the GMC motorhome where the existing Oldsmobile-sourced driveline was being phased out of production (the 403 and THM425 transaxle were phased out and replaced with the Oldsmobile 350 and THM325 when the downsized E platform was under development.) Prior to the introduction of the GMC Motor home, a handful of other manufacturers made use of a similar front-wheel drive configuration and inspired

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