Auxiliary sight parallelogram mechanics

-


Soviet MBTs utilize a parallelogram hinge mechanism which is used to link the vertical angular motion of the tank's main gun to the head mirror of the main sight. This is done by having 2 hinged parallelograms, one hinge as a common axis of rotation, which is brought into motion from an axis lever attached to a second hinge mounted through an eccentric bushing on the cannon's trunnions. The hinge for the common axis of rotation transfers vertical motion from the gun to the main sight while also duplicating the motion to the auxiliary sight. 

Basic parallelogram mechanism viewed from the right side

Basic parallelogram mechanism viewed from the top

Front view of parallelogram mechanism

On the left is the lever arm that connects to the auxiliary sight, and behind the gunner's sight is the connector bridge, which connects the cannon's trunnion through the main parallelogram drive on the right. The main drive has 2 lever arms, which connect to the right side of the sight. 
The left arm placement may vary due to some main sights utilizing an inbuilt bridge connector directly connecting to the auxiliary sight. This removes the need to duplicate the motion through a connector bridge. 

1G46 sight with 2 parallelogram linkage connectors. 

1A40 mechanical parallelogram linkage

Sights like 1A40(-1) have an internal linking bridge, which allows them to have a lever arm on the left side, allowing a direct connection to an auxiliary sight. For example, this would apply to the TPN-1-49-23.


1A40-1 sight. On the left is the linking bridge for pairing an auxiliary night sight.
 
Sights like 1G42 or 1G46 do not have such a feature, requiring sights like TPN-3, TPN-4 or PN-5 to get paired through a rear connector bridge mounted behind the main sight. This can be observed in the image with a hollow sight placement. 

TPN-1-49-23 with a single link arm connector.

TPN-3 with a single link arm connector.

TPN-4 Buran-PA with single link arm connector

Along with the older generation night vision devices, many of the late Soviet and early Russian thermal sights, like AGAVA-2 or Nocturne, use this parallelogram-linkage method to synchronize the mirror with the main sight. 

AGAVA-2 sight. 1: rear connector bridge, 2: connector arm, 3: parallelogram connector

Nocturne thermal imaging sight with a parallelogram mechanism

The 1PN-96MT is an auxiliary thermal imaging sight, which uses the same parallelogram-linkage method to synchronize the internal mirror with the main sight mirror. 1PN-96MT has 2 parallelogram connectors requiring 2 lever arms. This allows the sight to not have its own inbuilt stabilization mechanism and instead rely on the main sight to stay on the correct LoS.

1PN-96MT-01 paired with 1G46 sight

1PN-96MT with 2 connector points for parallelogram-linkage

References: 
  • Arms-Expo.ru - 1A40-1 tank sight
  • Poisk.ru - 1G46 
  • Михаил Барятинский, Т-72 Уральская броня против НАТО - Mikhail Baryatinsky, T-72 Ural Armor against NATO
  • Patent: RU2713717С1 
  • УСТРОЙСТВО ОРУЖИЯ И ЕГО БОЕВОЕ ПРИМЕНЕНИЕ. Учебник в двух частях. Часть вторая. Омск, Издательство ОмГТУ, 2012
  • С.А Беляков, ПРИБОРЫ НОЧНОГО ВИДЕНИЯ БРОНЕТАНКОВОЙ ТЕХНИКИ, Учебное пособие, Омск 2001
  • ТАНК Т-72А ТЕХНИЧЕСКОЕ ОПИСАНИЕ И ИНСТРУКЦИЯ ПО ЭКСПЛУАТАЦИИ КНИГА ПЕРВАЯ, МОСКВА ВОЕННОЕ ИЗДАТЕЛЬСТВО 1986

Comments

Post a Comment

Popular posts from this blog

"AGAVA" - "AGAVA-2" and its confusing history

-
Image
When covering Soviet sight technology there are always some interesting designs and approaches to solving an issue. It is a common fact that the Soviet Union in the 1980s-1990s was quite behind in thermal sight technology. Only in the 1990s, but to be specific in 1992, the Soviet Union now Russia started to field small batches of thermal sights on their tanks, primarily T-80Us and some of the early T-90 variants, which just recently entered service. Russia's journey through creating its own domestic thermal sight traces back to 1982.  The 1980s were quite an important time for the 'Krasnogorsk Factory named after S.A Zverev', which is still to date an Optical Engineering and Optoelectronics factory. The factory is primarily known for making domestic Soviet cameras back in the day. However, that's not the only thing that the factory has produced back then.  Close to the mid-1980s, the facility was contracted to develop new thermal sight technology for the Soviet Ministry
Read more

GTD-1000 - GTD-1000TF - GTD-1250 Gas Turbine Engines

-
Image
The world's first mass-produced tank gas turbine engine GTD-1000T was created at the Klimov Plant in 1968 for the T-80 main battle tank developed By the special tank design Bureau of the Kirov plant (now JSC "Spetsmash"), which was adopted by the Soviet Army in 1976. Since 1980, a modification of the GTD‑1000TF for T-80B/BV tanks was produced, since 1986 a modification of the GTD-1250 for T-80U tanks.  GTD-1250 Engines of the GTD-1250 family as part of the power plants of T-80 tanks are in service with the armies of Russia, Belarus, Cyprus, South Korea, Kazakhstan. Turbine engine GTD-1000T/GTD-1250, which have a large volume-weight  capacity and a more favourable traction characteristic compared to diesel engines, provide T-80 tanks with interesting characteristics: - higher operational readiness - easy start-up at low temperatures (up to -40°C) - better cross-country ability on soils with a low load-bearing capacity - best noise and heat-masking qualities - increased &qu
Read more

A new sight for the modernized T-90

-
Image
  Back in 2018, a new programme was started. This programme's focus is to create domestic equipment for Russian armoured vehicles, specifically optics. This is so that the Russian army can stop depending on the french company "Thales" and their Catherine technology. T-72B3 received new internal components for the Sosna-U sight, phasing out any foreign components. As for the T-90M/T-90MS, something else was done. Previously, the T-90M/T-90MS employed the Sosna-U sight, which featured french components from Thales. However, the internals of the sight was not simply replaced. This time, a completely new domestic sight was created under the name PNM-T. The sight was reportedly made by the PJSC ANPP TEMP-AVIA in 2018 or 2019. The first appearance was in the Telekanal Zvezda show, during the episode about the Proryv-3 (T-90M). In this episode, a new plaque can be seen with the name of the sight. Its first public physical appearance, however, was at the Army-2019 event. The doo
Read more