Unipower
Page 79
If you've noticed an error in this article please click here to report it so we can fix it.
New Four-wheel-drive Tractor of 85 b.h.p. and with Ten Speeds AN interesting new tractor is the chief item among the latest products of Universal Power Drives, Ltd., Perivale, Middlesex. Thi machine has a four-wheel drive, a transmission arrangement incorporating a five-speed primary gearbox and a two-speed auxiliary gearbox, from which large tubular propeller shafts run rearwards and forwards to the axles. These shafts have Rzeppa constant-velocity universal joints at their gearbox ends, and Hardy Spicer needle-roller joints at the axle ends.
The pewer unit employed has six cylinders, side valves and cylinder dimensions of 101.6 mm. x 107.75 mm., giving a capacity of 5.244 litres. It develops 85 b.h.p. at 2,800 r.p.m., a maximum torque of 205 lb.-ft., at 1,000 r.p.m. With the clutch and gearbox,
it forms a unit, which is mounted at threepoints on iubber.
In answer to the obvious .question, how is the drive transmitted to the frOnt. wheels without interfering with the steering arrangements, etc., it is found that further use is made here of Rzeppa universals. The front axle is equipped with a patented arrangement of driving and steering ends, and, as is well known, the special joint employed for transmitting the drive functions through a wide angle.
Exceptionally deep side members measuring in section 12 ins. x 3 ins, x
in., sturdily braced with full-depth cross-members and with a system of triangulation at the rear, are features of the main frame, which is supported on semi-elliptic springs at both front and rear. In this connection it may he pointed out that the deep rear cross member gives a degree of latitude in positioning the towing hook and that the diagonals transmit the pull scientifically.
Girling brakes are applied through a Dewandre vacuum-servo system.
It is of note that no less than three power take-offs are provided, two on the primary gearbox and one on the auxiliary box. Th4 last-named should prove a particularly useful adjunct, giving full engine power and being located in a convenient position.
Provision is made for braking the wheels of the trailer, used in conjunction with this Unipower tractor. A hand-brakelever and connections are provided, whilst means are afforded for interconnecting the vacuum system with brakes on the trailer wheels.
With regard to equipment, the lighting systemis of C.A.V.-Bosch make and includes a 6-volt 100-amp.-hr. battery. There are twin towing hooks at the front and a single hook at the rear, and in addition a substantial bumper. The radiator shell is as plain as possible and made of extra heavy gauge material. Finally, the machine is largely built of standard components which can be readily and cheaply serviced.
Perhaps most well-known of the Unipower products is the two-axle bogie, mostly used for converting four-wheelers to rigid sixwheelers. For 1938 a number of improvements has been effected to this unit. which has a capacity of 8 to 10 tons.