Casket Lowering Device Product

Overview

A casket lowering device is a motorized mechanical system designed to lower a deceased person in a casket into a grave at a slow, dignified, controlled speed. The device eliminates manual rope handling and prevents sudden drops or uneven descent that can disturb mourners and damage the casket. Modern units feature motorized drum-and-strap systems with mechanical governors as a failsafe against catastrophic descent if electrical power is lost.

Every cemetery and graveyard uses casket lowering devices; they are standard equipment at graveside services. The device is positioned over the grave opening before the funeral service, supporting the casket on webbing straps while pallbearers stand by. At the end of the service, the funeral director activates the device via foot pedal or pendant, lowering the casket at a preset rate (typically 30–90 seconds) while mourners observe. The system is then raised and removed for burial.

Core subsystems include the Main Span Frame span beam, the Spooled Strap Drums motor-driven spools, the Motor & Speed Reducer speed control, the Centrifugal Governor Brake mechanical failsafe, the Operator Control Station operator interface, the Casket Strap System casket support, and the Adjustable Leg Assembly adjustable support legs.

How It Works

Before the funeral service, the lowering device is set up over the grave opening. The Adjustable Leg Assembly are adjusted to the appropriate height via Leg Lock Pin pins so that the Main Span Frame beam sits 1–2 meters above ground level. The Spooled Strap Drums are wound with enough Synthetic Spool Webbing to reach from frame to grave bottom.

The casket is positioned over the grave and the Casket Strap System webbing straps are placed under the casket at four or six points (shoulders, torso, legs, ankles). Carabiners on the strap ends are clipped to the Synthetic Spool Webbing spooled on the drums, connecting the casket to the lifting apparatus. At this point, the casket is fully supported; pallbearers step back.

When the funeral director is ready, he/she presses the Descent Speed Pedal or wireless pendant. The Electric Motor activates at low speed (controlled by the Variable-Frequency Drive), turning the Gear Speed Reducer which drives the Drum Drive Shaft connecting the two Spooled Strap Drums. As the drums rotate slowly (5–10 rpm), webbing unwinds off the drums, allowing the casket to descend at a steady rate.

The descent speed is typically preset: 30–60 seconds per 6 feet (approximately 0.3 m/sec), though it can be adjusted at installation or in real-time via the Speed Setting Control. As the casket reaches grave bottom, the operator eases the Descent Speed Pedal to a stop, bringing the casket to rest. The Electric Motor shuts off, and the webbing straps are manually detached from the drums by gravediggers. The empty lowering device is then raised back to surface height and wheeled away.

The entire descent typically takes 45–120 seconds depending on grave depth (2–3 meters typical), providing time for family members to observe the casket being lowered while maintaining dignity and control.

Governor Brake & Safety

The Centrifugal Governor Brake is the critical safety component, providing redundancy if electrical power is lost or a strap tears. The governor is a mechanical centrifugal system mounted on the drum shaft. Two weights (Governor Centrifugal Weight) rotate with the drum on a spring-loaded pivot. During normal controlled descent (5–10 rpm), centrifugal force on the weights is low, and springs hold them retracted. The brake shoes stay disengaged.

However, if a strap tears and the casket free-falls, drum RPM suddenly increases toward 25+ rpm. At this point, centrifugal force exceeds spring tension, the weights fly outward, and the Governor Brake Shoe friction pads engage the drum surface with high friction (coefficient >0.4). This creates a braking torque that quickly decelerates the drum, limiting the descent to a safe rate (terminal velocity of casket under gravity + brake resistance, typically 0.5–1 m/sec). This mechanical failsafe operates without electrical power and requires no operator intervention.

A RPM Speed Sensor monitors drum RPM and triggers an alarm if over-speed is detected, alerting bystanders to a problem. An Emergency Stop Button red emergency stop button cuts motor power immediately and solenoid-engages a mechanical brake.

Straps & Casket Connection

The Casket Strap System is the load path between the casket and drums. Four or six Casket Strap Webbing Leg legs (50 mm wide polyester webbing, 600–800 mm length each) are positioned under the casket—typically at the four corners and optionally at the head and feet for better distribution. Each strap terminates in a Strap Carabiner Clip carabiner clipped to the Synthetic Spool Webbing wound on the drums.

A Casket Load Ring central ring clipped at the casket contact point distributes load evenly to all four straps. This prevents any single strap from bearing the full casket weight and ensures symmetrical lowering. Strap Contact Pad foam padding under each strap contact point prevents marking or damage to the casket exterior, which is cosmetically important for the service.

Total strap capacity is typically 2000 kg (500 kg per strap × 4), providing a 4:1 safety factor over a 500 kg casket—well beyond typical usage but critical for safety.

Frame & Support Structure

The Main Span Frame is a lightweight aluminum or steel beam (I-beam or box-tube, 100 × 100 mm section, 2000–2500 mm long) spanning the grave opening. Aluminum (6061-T6) is increasingly preferred over steel for lower weight (easier to position) while maintaining rigidity. The frame deflects <5 mm under 500 kg load, ensuring the Spooled Strap Drums remain level throughout descent.

Four adjustable Adjustable Leg Assembly telescope from 500–800 mm height, accommodating shallow and deep graves as well as ground slopes. Each leg locks in place via a Leg Lock Pin pin. Leg Ground Foot rubber pads at the base distribute load (125 kg per leg for a 500 kg casket) to the ground without sinking or tipping.

A Protective Safety Rail protective guard encloses the machinery (motor, gearbox, drums) preventing operator or mourner contact with rotating parts. Posts and horizontal bars form a cage; optional mesh infill further restricts access.

Drive System

The Electric Motor is a small AC induction motor (0.5–1 kW, 110V or 240V single-phase). To achieve the low descent speeds required (0.3–0.5 m/sec), the motor drives a Gear Speed Reducer reducer with a high ratio (30:1 to 50:1). This reduces the motor's 1450 rpm output to 5–20 rpm at the drum, suitable for controlled casket lowering.

A Variable-Frequency Drive variable-frequency drive modulates motor speed from 0–100%, allowing real-time adjustment of descent rate via the Descent Speed Pedal. Foot pressure translates to a proportional speed signal (0–10 kΩ potentiometer output); light pedal pressure gives slow descent (45–60 seconds per 6 feet), and heavier pressure accelerates the descent (down to 30 seconds minimum). This operator control is critical for accommodating different grave depths and psychological comfort levels of mourners.

The Drum Drive Shaft connects the gearbox output to both drum hubs via a spline coupling. A Flex Coupling flexible coupling accommodates minor shaft misalignment from frame deflection under load.

Operational Controls

The Operator Control Station houses the operator interface. A Descent Speed Pedal mounted on the frame allows the funeral director to stand near the device and control descent with foot pressure—both hands remain free for other tasks or for providing support to mourners. Alternatively, a wireless pendant may be provided for remote operation if the director needs to stand elsewhere during the service.

The Speed Setting Control allows pre-setting the descent profile (0–30 seconds per 6 feet); some models use a digital timer or speed selector. Status is indicated by Status Indicator Light LEDs—green for ready, red for fault or over-speed condition.

An Emergency Stop Button red emergency stop button cuts power and mechanically engages the brake, allowing immediate stopping if anything goes wrong.

Maintenance & Inspection

The Motor & Speed Reducer unit is sealed and maintenance-free for most operators; annual professional inspection of gear oil level and bearing condition is recommended. The Centrifugal Governor Brake weights and brake shoes are inspected annually to ensure smooth motion and proper engagement. The Synthetic Spool Webbing is checked for fraying, abrasion, or UV degradation; straps are replaced every 5–10 years or after 500+ cycles.

The aluminum Main Span Frame requires minimal maintenance but should be checked for corrosion, especially in coastal environments. A well-maintained device operates reliably for 20+ years, providing hundreds of services per year.